egg quality

In the world of reproductive health and fertility, there is a growing interest in understanding the quantity of eggs a woman has, also known as ovarian reserve. The concept of measuring ovarian reserve has gained popularity as more people seek to assess their fertility potential and make informed decisions about family planning. 

But can you truly measure how many eggs you have? Let's delve into the world of ovarian reserve testing and explore the possibilities and limitations.

How many eggs do females have?

Females are born with approximately one to two million oocytes, and it only goes down from here since no new eggs are made. But here's where it gets interesting.

Once we reach puberty, a process triggered by a complex interplay of hormones, only about 300,000 of these oocytes will remain. These precious few will have the opportunity to mature and potentially be released as eggs during our reproductive years. Our bodies typically release just one egg per menstrual cycle, and this process occurs approximately 400 times throughout our lifetime.

These remaining oocytes are not merely passive bystanders. Each one resides within a protective structure called a follicle, where it lies dormant and suspended in the middle of a cell division. Remarkably, the lifespan of an egg is one of the longest among the body's cells. However, this extended duration can also increase the chances of damage and genetic abnormalities as we age.

At menopause, which is defined as one year after your last menstrual period, the pool of remaining oocytes steadily declines until none remain. This natural process signifies the end of our reproductive years.

Understanding the intricacies of egg development and the limited supply available underscores the importance of considering fertility and family planning at an earlier age. Each egg is a precious resource, and its quality and viability can impact the chances of achieving a successful pregnancy. Exploring fertility preservation options, such as egg freezing, can provide women with greater control over their reproductive future.

While the numbers presented here provide a general understanding, it's crucial to remember that everyone’s ovarian reserve is unique. Factors like genetics, lifestyle, and overall health can influence the rate of egg loss and fertility potential. 

Egg count and age

As stated above, females are born with one to two million eggs. By puberty, only about 300,000 of these oocytes will remain. After starting the menstrual cycle, we lose about 1,000 immature eggs every month… meaning by age 37 there are around 25,000 eggs remaining. And by menopause, no more eggs remain.

Here is a rough chart of what this could look like for an individual. Keep in mind that everyone starts with a different number of eggs, and everyone’s rate of decline varies. This chart is just to give you an idea of what this egg count could look like: 

Measuring egg reserve (aka ovarian reserve)

Ovarian reserve refers to the number of eggs remaining in a woman's ovaries at a given time. It is one indicator of a woman's reproductive health, and can help guide fertility treatment decisions. The idea of quantifying ovarian reserve has gained significance as women strive to gain insights into their fertility and make proactive choices about their reproductive journey. And at the same time, at-home tests make it easier to measure your ovarian reserve.

Keep in mind that the number of eggs you have does not necessarily equate to your ability to conceive. Other factors, such as egg quality, the presence of any reproductive disorders, and the overall health of the reproductive system, play significant roles in fertility. Not to mention the health of the sperm! Some people have lower ovarian reserve but still achieve successful pregnancies, while others with a seemingly healthy ovarian reserve may face challenges in conceiving.

How to measure ovarian reserve

One of the most commonly used methods to measure ovarian reserve is through a blood test that evaluates specific hormone levels. These hormones include anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), and estradiol. AMH, in particular, has emerged as a reliable marker of ovarian reserve, as it reflects the number of small follicles in the ovaries that contain immature eggs. Low levels of AMH may indicate a diminished ovarian reserve, while higher levels may suggest a larger pool of eggs.

While ovarian reserve testing provides valuable insights, it is not a crystal ball that can predict fertility outcomes with absolute certainty. Ovarian reserve is just one piece of the fertility puzzle, and other factors such as egg quality, uterine health, and sperm quality also play crucial roles in the conception process. Additionally, fertility is influenced by various external factors, including age, lifestyle, and underlying health conditions.

Fertility testing can provide a snapshot of ovarian reserve at a specific moment in time. Ovarian reserve naturally declines with age, and the number of eggs available for fertilization decreases over time. Therefore, it's crucial to interpret the results in the context of your age and overall health.

Egg reserve testing methods

Another consideration when evaluating ovarian reserve is the variation in testing methods and reference ranges used by different laboratories. Each laboratory may have its own set of standards and measurements, which can lead to variations in results. You may want to consult with a fertility doctor who is knowledgeable in reproductive medicine to interpret the test results accurately and provide personalized guidance (if you work with Cofertility, we can help you set this up).

So, can you measure exactly how many eggs you have?

While ovarian reserve testing can provide valuable information, determining the exact number of eggs a woman has remaining in the ovaries is not possible. 

Why? First of all, the number of eggs in the ovaries is not static but rather dynamic and constantly changing. We are born with a finite number of eggs, and this number gradually declines over time through a process called follicular atresia. This natural process of egg loss occurs throughout our reproductive years, and the rate of decline varies from person to person.

Second, the accuracy of measuring the exact number of eggs is hindered by the limitations of current medical technology. While imaging techniques like ultrasound can visualize the presence of ovarian follicles, they cannot precisely determine the number of eggs within each follicle. Additionally, even if the number of follicles can be counted, it does not equate to the exact number of eggs, as not all follicles contain a viable egg.

Ovarian reserve is just one piece of the puzzle

While ovarian reserve testing can provide valuable information, it is just one tool in the broader landscape of fertility assessment. A fertility doctor can consider your medical history, conduct a physical examination, measure your antral follicle count, and may recommend additional tests or imaging studies to provide a comprehensive assessment of your reproductive potential.

‍

Cofertility is a human-first fertility ecosystem rewriting the egg freezing experience. With our Freeze by Co platform, women can freeze their eggs for free when they donate half of the retrieved eggs to a family who can’t otherwise conceive. We are obsessed with improving the family-building journey — today or in the future — and are in an endless pursuit to make these experiences more positive.

More and more people are freezing their eggs; in fact, in 2021 we saw a 46% increase in egg freezing cycles in the United States. If you’re exploring egg freezing, you may have a lot of questions, including if you can stay on birth control or not. In this article, we will discuss how birth control works and answer common questions about egg freezing while on various types of birth control.

How birth control works

Birth control methods work in various ways to prevent pregnancy. Hormonal methods, such as the pill, patch, ring, and injection, regulate hormones in the body to prevent ovulation. Without ovulation, there is no egg available for fertilization.

Non-hormonal methods, such as condoms, diaphragms, and intrauterine devices (IUDs), physically prevent sperm from reaching the egg or alter the environment in the uterus to prevent implantation. IUDs can be either hormonal or non-hormonal, depending on the type.

If you are freezing your eggs, do not start or stop your current birth control regimen without talking to your fertility doctor. 

Can I freeze my eggs while on the pill?

You will need to stop taking the pill before the actual egg freezing cycle. That’s because hormonal birth control is intended to prevent ovulation, but during freezing you want to do exactly the opposite. Some doctors will have you stop during your egg freezing cycle, and some may have you stop for the month leading up to the retrieval. 

The irony is that in preparation for an egg freezing cycle, the birth control pill is commonly prescribed for two to three weeks to sync your cycle and reduce the chance of inducing a cyst from the ovulation follicle. It can also help synchronize the cohort of follicles for a more optimal response. So if you’re not on the pill, you may be prescribed birth control pills with the start of the menstrual cycle in which you plan to undergo the egg freezing cycle.

Can I freeze my eggs while on Depo-Provera?

Depo-Provera (medroxyprogesterone acetate) is an injection that contains a synthetic form of the hormone progesterone. Since this shot can interfere with hormonal medications, you may have to wait up to three to six months after the last shot until your ovaries are in an optimal state to be stimulated.

While Depo-Provera can affect the timing of ovulation, it does not impact the number or quality of eggs that are retrieved during the egg freezing process.

Can I freeze my eggs with an IUD?

Yes! Unlike other forms of birth control, IUDs do not prevent ovulation and therefore will not get in the way of stimulating egg production during your freezing cycle. If you have an IUD, there’s no need to remove it before your cycle. Although if you’ve been meaning to take it out, ask the doctor if they can do it during your procedure. 

Studies show that egg and embryo freezing results are the same for patients with or without IUDs.

Can I freeze my eggs with Nexplanon (birth control implant)?

Nexplanon is a small rod inserted under the skin of the upper arm that releases a synthetic form of the hormone progesterone. While it may not directly impact egg quantity or quality, some clinics require it to be removed before starting the egg freezing cycle. This is ultimately up to your physician's protocol, so it’s important to check with your clinic. In many cases, removal and reinsertion of the implant is covered by insurance.

Can I freeze my eggs with the patch?

Like the pill, the patch contains synthetic hormones that regulate the body's natural hormone levels and prevent ovulation. In order to begin an egg freezing cycle, you will need to remove the patch. 

Can I freeze my eggs with NuvaRing?

The NuvaRing is a vaginal hormonal birth control ring. Because it’s using hormones to prevent ovulation, like the pill and the patch, you will need to remove the NuvaRing before your cycle. However, your fertility doctor will give you instructions and there’s no need to remove it until they tell you to. 

Why is my doctor prescribing birth control to freeze my eggs?!

While it may seem counterintuitive, many fertility doctors recommend or prescribe birth control at the beginning of the egg freezing process. There are several reasons why:

• To coordinate the timing of stimulation start. Hormonal birth control pills can be used to offset the menstrual cycle to help facilitate the best timing for your cycle with your clinic/lab.
• To reduce the likelihood of ovarian cysts. Birth control pills may help to suppress the growth of ovarian cysts, which can interfere with the egg retrieval process. 

So while it may seem counterintuitive, using birth control pills before egg freezing is pretty typical. 

Summing it up

Hormonal birth control methods work by regulating hormones in the body to prevent ovulation, while non-hormonal methods physically prevent sperm from reaching the egg or alter the environment in the uterus to prevent implantation. While it is possible to freeze your eggs while on various types of birth control, it depends on which one. 

• Definitely okay: condoms, diaphragms
• Generally okay: IUD, birth control implant
• Need to stop: the pill, the patch, NuvaRing
• Potential wait of three-six months: Depo-Provera

Of course, do not start or stop your current birth control regimen without talking to your fertility doctor first.  

Freeze your eggs with Cofertility

Cofertility is in the “family” business, striving to make egg freezing and third-party reproduction more human-centered and accessible for all. Our Freeze by Co program allows you to freeze your eggs for free when you give half of the eggs retrieved to a family who can't otherwise conceive.

More people than ever are thinking about preserving their fertility for the future. But what’s the difference between freezing eggs and freezing embryos? More importantly, which is the better option for you?

While both procedures have given people more choice around when they have children and how they conceive them, they’re not the same and there’s plenty to think about when trying to choose one over the other.

What’s the difference?

There’s one major difference between freezing eggs and freezing embryos. When you freeze your eggs, they stay unfertilized. We all know that to make a baby, you need an egg and a sperm because each of them provides half of the material needed. On its own, an egg can’t function (and neither can a sperm).

An embryo, on the other hand, is an egg that has already been fertilized by a sperm. Once they combine, the egg and sperm become a single cell. Over the next three to four days, the embryo divides several times, going from one to two to four to eight cells, and so on until it reaches the blastocyst stage and is ready to be frozen. Once an embryo has developed, there’s no going back– that is, there’s no way to turn that embryo back into a separate egg and sperm. 

Things to consider

So how does this information help you figure out whether to freeze eggs or embryos? Well, there are two big factors to consider: your circumstances and the research.

If you don’t know who you want to have children with, then freezing your eggs may be the best approach. This option gives you the freedom to hold off on thinking about having a baby until you’ve met someone or are ready to choose a sperm donor. 

On the other hand, if you are currently with a partner who you know you’d like to have children with but now isn’t the right time, then freezing embryos might be the way to go. The caveat here is to be 100% certain—stars like Sofia Vergara and more recently, Anna Kendrick, have run into trouble after freezing embryos with partners they didn’t end up with. 

Now, let’s look at the research.

Is freezing embryos really better?

The short answer here is not necessarily. The long answer is that each case is unique so whether freezing embryos or eggs is the better option for you will depend on your specific situation and what your labs, imaging, and other health information suggest. 

With that in mind, let’s break down the pros and cons of each method.  

Pros and cons of freezing eggs vs embryos

Freezing/thawing process

Historically, embryos have been “tougher” than eggs and therefore, easier to freeze and thaw. Freezing eggs was much more of a gamble since they’re large cells with a lot of water inside. That water can turn into ice crystals during freezing which, in turn, can damage the chromosomes in the eggs and make them unusable.

But it’s not all gloom and doom for egg freezers! Researchers have continued to study the technology and the statistics have changed as newer and better freezing technologies have emerged. Nowadays, an excellent lab can expect 97% of the eggs that they freeze to survive compared to 95% for embryos. 

But, let’s be clear, these numbers don’t mean that your chances of a successful live birth are 3% higher with frozen eggs, it just means that they are a little more likely to make it to the next phase of IVF. The higher the quality of your frozen eggs (i.e. if you freeze your eggs relatively young and maintain a healthy lifestyle), the more likely they will have thaw rates that are just as good (if not higher) than that of embryos.

Quality

A major weakness of egg freezing is that there is no way to test the quality of eggs on their own–they still have to make it through the thawing process, fertilization, and develop into a healthy embryo that can be implanted into the uterus (not all of them make it this far).

This can lead to a situation where someone uses their eggs years after freezing them and those eggs don’t perform as well as they thought they would. By then, this person is older so their egg quality has declined even more. Not having that quality information upfront can make it hard to judge how many eggs need to be frozen to lead to an actual baby.

In contrast, embryos have to get past several important hurdles that give fertility specialists a much better sense of their quality and the chances of a baby later. That’s because turning eggs into embryos requires that they be successfully fertilized and that those embryos survive up to a point where they can be frozen (usually the blastocyst stage, around day 5 of development). 

In addition, embryos are graded at each point in their development based on an embryologist’s opinion of whether they are high quality or not (embryologists are experts who study the development of embryos). 

Finally, you have the option to run a genetic screening test on embryos, which can help more accurately predict whether they’re likely to become healthy babies. Research has shown that preimplantation genetic screening can result in lower miscarriage rates and higher live birth rates per embryo transfer. There is no such test for frozen eggs. 

Chances of a healthy baby down the line

Recent studies comparing the likelihood of actual babies being born, known as the live birth rate (LBR), have shown that it’s now pretty even whether you’re freezing eggs or embryos. Before this, the LBR with frozen eggs was quoted at about 50% the LBR of frozen embryos. 

A study published in May 2022 provides even more evidence to support this. The study, done at NYU, is the largest U.S. report of elective fertility preservation outcomes to date and is based on 15 years of real-life frozen egg thaw outcomes for people who had delayed having children and had natural, age-related fertility decline.

On average, study participants were 38 years old at the time they froze their first set of eggs. The study found that regardless of age, those who thawed at least 20 mature eggs had a 58% LBR. This was unexpected given that so many of the participants were past the optimal age to freeze eggs (35 years old or younger). People under 38 years old who thawed 20 or more mature eggs had a 70% LBR per patient. The length of frozen egg storage did not change the success rate.

Additionally, the study found that 39% of people between 27 and 44 years old (most were between 35 and 40 when they froze their eggs) had at least one child from their frozen eggs, which is comparable with age-matched in vitro fertilization (IVF) outcomes. Researchers also found that many of the participants studied had more than one child through egg freezing. 

When compared to data collected by the Centers for Disease Control and Prevention (CDC) from the nation’s nearly 500 fertility clinics on people trying to conceive at age 40 using fresh eggs or embryos, only 30% who underwent IVF became pregnant and the LBR was less than 20%.

The final conclusion? For those starting families later, egg freezing and thawing at a later date provides a higher pregnancy success rate than using fresh embryos during assisted reproductive technology.

‍

*One important point the researchers make about their study is that it was limited by the number of patients. More studies need to be done in the future that include people from a variety of geographic locations and center types. 

Cost

Last, but certainly not least, is the financial side of this. Is embryo freezing more expensive than egg freezing?

Honestly, yes. The upfront cost of egg freezing is definitely less than that of embryo freezing (which requires in vitro fertilization before freezing). While egg freezing costs upward of  $10,000 on average, creating and freezing embryos can add a few more thousand dollars to that bill. If you’re freezing embryos using a sperm donor, the sperm can add a further $300 to $4,000, depending on several factors. In both cases, you will also need to pay an annual fee to store your eggs or embryos until you use them. This can cost anywhere from $500-$1000 per year, depending on the clinic you use. 

Depending on the type of medical coverage you have, your insurance may cover some of these costs, so make sure you reach out and see what support you can receive from them. Many clinics also offer financial plans and other forms of support so always ask!

TL;DR: Freezing eggs comes with a lower upfront price tag which makes it an easier and more accessible choice than embryo freezing, allowing more people to preserve their future options. 

Additional Resources

Both the Centers for Disease Control & Prevention (CDC) and experts at Harvard Brigham and Women’s Hospital have developed calculators for assessing a person’s chances of success with artificial reproductive technology (ART). The CDC IVF Success Estimator helps estimate the chances of a live birth with IVF while the BWH Egg Freezing Counseling Tool helps to estimate the chances of at least 1 live birth based on your age and number of frozen eggs.  

What do I ask my provider?

Use your health care provider as a support and resource. They should be able to answer any of your questions. Not sure what to ask? Here are a few questions to help you get started: 

• How many eggs or embryos do you recommend I freeze, at my current age, to have the highest percentage chance of a live birth later on?
• How many treatment cycles will I need to do to get to this number? It’s totally normal to need more than 1 cycle, but it’s nice to know what to expect ahead of time. 
• What is this lab’s rate of successful freezing and thawing of eggs vs embryos (“oocyte cryosurvival rate” is the medical term)? Are they closer to minimal or maximum competency?
• How much would each cycle cost? 
• Are there any financial support options, plans, or advice? 
• What are the health risks? What about common side effects? 
• Is there an upper age limit for using my eggs or embryos in the future? 
• How long can I store them and how much will it cost per year?

Do You!

At the end of the day, there’s no universal rule around the best approach to preserving fertility. Family planning is going to look different for every person so you need to do what’s right for you. When you’re ready, talking to a fertility specialist can help you make up your mind. 

In the meantime, Freeze by Co is here to help you every step of the way on that journey. Our Split program allows those who qualify to freeze their eggs for free! In a “Split” cycle, you donate half of the eggs retrieved to a family that’s trying to conceive and freeze the remaining half for yourself. Or, if you don’t want to donate, you can still participate in the Keep program, where you’re able to freeze your eggs and keep them all for yourself, on your timeline. In addition, you’ll have access to our online support community. This valuable resource lets you engage with other people freezing their eggs at the same time! 

Whatever you end up choosing for yourself, our team is here to guide you through it and keep your options open.

You might have heard at some point that freezing your eggs can help you preserve your fertility options for your long term future. But just how many eggs should you freeze? Is there an optimal number for egg freezing?

Let’s take a look at how many eggs you can expect to get during the retrieval process and how many eggs you should be freezing for fertility preservation. 

How many eggs do I have?

Before we talk about the number of eggs you should freeze during oocyte cryopreservation — more commonly known as freezing your eggs — we should probably talk about how many eggs are in your ovaries right now. 

Your fertility doctor may have mentioned the term ovarian reserve a few times. When they do that, they’re talking about the number of eggs in your body. But how many eggs are in that reserve?

There is no exact answer here. On average, women are born with anywhere from one to two million eggs. Some women are born with more. Some women are born with less. 

It may sound like a lot either way, but most of the eggs we’re born with don’t stick around. By the time most of us hit adolescence,we have about 300,000 eggs left. From there, the number of eggs in the body naturally decreases by about 1,000 every year, and the decline becomes more rapid after age 35.  

That’s where egg freezing comes into play. The doctors of the Association of Reproductive Medicine (ASRM) states that planned oocyte preservation is “ethically permissible” because it provides women with more autonomy over their reproductive choices. 

Doctors can get a sense of how large your ovarian reserve is before egg freezing by testing the level of the anti-Müllerian hormone (AMH) in your body. This test looks at both your ovarian reserve and how well your body may or may not respond to medications that will stimulate the ovaries. What it can’t determine, however, is the quality of those eggs. And ultimately, you need both quantity and quality.

How many eggs do I need to freeze?

OK, so you may have a lot of eggs in your ovarian reserve — or maybe not. But how many do you actually need to freeze?

This answer varies from person to person and depends on a few individual factors:

• How old are you right now?
• Do you plan to freeze all of your eggs or do you hope to also donate some to help intended parents grow their family? 
• If you think you may want to have children one day, how many do you have in mind?

This list presents a lot to think about, so let’s dive a little deeper to help you make informed decisions about the number of eggs you freeze. 

The right number of eggs to freeze for your age

Different folks have different reasons for freezing their eggs. Some may be thinking about prolonging their fertility into the future. Others may be freezing some eggs but also hoping to donate some eggs to help others grow a family — something that’s done via our Split program, where you freeze for free when donating half of the eggs to a family that can’t otherwise conceive. 

Either way, studies have found that the optimal number of eggs to freeze really comes down to your age. That’s because the number of eggs in the body isn’t the only thing to decrease as you get older — egg quality decreases too, and egg quality is the number one factor in determining whether an egg can eventually result in a live birth. 

Here are the number of eggs you’ll want to freeze based on your age in order to obtain an optimal live birth rate:

How many eggs are retrieved?

For  egg donors aged 25-29, the average number of eggs retrieved is 18, and that number drops to 16 for people age 30-35 — although it varies from person to person.

Your reproductive endocrinologist will be able to tell you the day of your retrieval how many eggs were retrieved. This number will include both mature and immature eggs, so it’s not necessarily the total number of eggs that can be frozen. 

Immature Eggs

• May be partially or completely damaged or have its quality compromised in some way
• Lower chance of fertilization

Mature Eggs

• Have good egg quality
• Are more likely to be fertilized
• Can be frozen

After your retrieval, all of your eggs will be sent to an incubator to check maturity. The lab technicians will look for eggs to achieve meiosis, a kind of cell division that occurs in egg cells. 

The eggs that achieve meiosis will be frozen, and you will be notified of the total number. 

Should I do multiple egg retrievals?

What happens if you don’t get as many eggs as you had hoped during your egg retrieval cycle? 

If you’ve undergone one round of egg freezing and the number of eggs your reproductive endocrinologist retrieved from your ovaries wasn’t as high as you’d hoped, you may want to talk to them about trying again. 

There is technically no limit to the number of egg freezing rounds a person can undergo, but it’s not recommended that egg donors undergo more than six cycles. If you’re hoping to split your eggs with intended parents (donating half of the eggs retrieved) as part of our Split Program, you may find that additional retrievals help you provide the optimal amount of eggs for a live birth for you and for the intentend parents too. 

Of course, you should talk to your doctor about any risks or benefits that come with additional rounds. 

The right number of eggs to freeze to have multiple children

If you’re planning to have a big family one day, you may want to look at the number of eggs it’s recommended you freeze to achieve one live birth and talk to your doctor about freezing more eggs. 

For example, the studies show that a woman under age 35 will need to freeze about nine eggs to achieve a 70% chance of a live birth. If you’re under age 35 now and thinking you might want to use frozen eggs to conceive twice in your future, you will want to freeze closer to 18 eggs to achieve that 70% chance each time. 

That number will increase with each number of children you foresee — provided your expectation is that each child will be conceived with the use of the eggs you are currently freezing. 

Bottom line

There is no “magic number” when it comes to freezing your eggs. Your age, your future plans, and more all come into play. 

We’re here to answer any questions you might have, and the Cofertility community is also here to lend support as you consider all the important factors to make the choice that is right for you.

If you’re a female physician in the United States, you may have heard that you’re at a higher risk of infertility than your female friends who took a different career path. It certainly sounds like the kind of “fact’ that gets posted on social media one day and suddenly becomes gospel, whether it’s true or not. 

Unfortunately, we can’t just write this one off as a social media hoax. Researchers have run the numbers, and it turns out almost 25% of female doctors who are trying to conceive are faced with fertility challenges. This is about double the rate of the general public.

“It turns out almost 25% of female doctors who are trying to conceive are faced with fertility challenges. This is about double the rate of the general public. “

So what’s going on? Should you be freezing your eggs now just in case? Is there anything else you can do? Read on for the research into this fertility concern and what American doctors are doing about it. 

Female doctors and fertility

General fertility rates have been trending downward in the US in recent decades with the CDC reporting record low birth rates in 2018 and only minimal increases since. In 2021, the American birth rate was 1,663 births per 1,000 women — not enough to maintain stable population figures in the US. 

And while some of that could be due to personal choice, scientists have found increasing rates of reproductive problems are cropping up in women and men. Miscarriage rates are up about one % every year and so are the rates of gestational surrogacy — an option growing in popularity for intended parents seeking the help of an additional party for conception. 

But the plight of female doctors stands out among all these figures: 

• 1 in 4 — The approximate number of female physicians who were diagnosed with infertility after trying to have a baby, according to a survey published in the Journal of Women’s Health in 2016 
• 11 % — The percentage of American women in the general population have had the same diagnosis. 
• 42 % —The amount of female surgeons who have experienced a pregnancy loss, according to a survey published in JAMA Surgery in July 2021 which reported that 42 % had experienced a pregnancy loss. 

What’s going on?

What makes female doctors so different from the rest of the population? In part, their education. 

There’s no real way to put this nicely: Age matters when it comes to fertility. Extensive medical research on fertility shows that getting older has a major effect on our reproduction system and our ability to conceive.

But many female doctors — surgeons included — delay pregnancy until after the completion of their residency. How long that will take depends on the doctor’s specialty, but this can be another three to eight years after medical school. For surgeons, a residency is a minimum of five years. 

That puts many female doctors into their 30s before they even begin trying to have their first child. In fact, in the 2016 survey, doctors reported they were 31.6 year old on average at completion of medical school and residency and 30.4 years on average at first pregnancy. By comparison, the average age of an American woman giving birth for the first time in the US is 26 years old, according to data compiled for the New York Times in 2018. 

Almost a third — 28% — of the female doctors surveyed in 2016 who experienced fertility challenges said they would have begun trying to conceive earlier if they could have seen what lay ahead. Close to the same number — 29% — said they experienced diminished ovarian reserve, a condition in which their fertility challenge was linked to having fewer eggs in the body. This condition is largely associated with age. 

But delaying reproduction is only part of the puzzle.

Even after adjusting for age, female physicians have higher rates of infertility. Perhaps this is due to female doctors facing high rates of stress at work that put a strain on the body and can affect reproduction as a whole. Those who opt to start a family before residency is complete may face irregular work schedules and long, grueling shifts that can put intense strain on anyone’s body, but prove especially hard for someone who is pregnant.

Together, all of these factors can have a significant impact on the fertility of a female doctor. 

How can female doctors preserve their fertility?

The numbers may seem a little daunting, especially if you’re in medical school or the midst of your residency. So what can women do about it? 

An infertility task force now exists as part of the American Medical Women’s Association to find answers to this problem plaguing women in medicine, and individual doctors around the country have been working to advocate for improved fertility education and fertility insurance coverage for their peers. 

One of the chief criticisms of the current system comes from Dr. Areila Marshall, one of the founders of the AMWA task force, who wrote about the issue in the journal Academic Medicine in 2020 calling for better awareness of egg, embryo, and sperm cryopreservation. 

Marshall echoed a wish expressed by a number of the physicians who took part in the original 2016 survey: 7% of those doctors said they wished they had known to use cryopreservation to extend their fertility. 

For female doctors who don’t know when — or even if — they want to conceive, egg freezing can be a viable option. 

Freezing is not a guarantee that you will have a baby down the line. It simply means that eggs will be there, waiting, if you decide at some point in the future that you wish to explore conception. 

At Freeze by Co, we are committed to giving women the opportunity to have more control over their reproductive choices. Here women have a variety of paths they can choose from when it comes to egg freezing – whether they’re looking to freeze eggs now or have already frozen some of their eggs.  

Members of our Split program even freeze for free when they give half  of their eggs to intended parents who cannot otherwise conceive.

Bottom line

Women should not have to choose between a dream of pursuing a career in medicine and making reproductive decisions on their own timeline. Egg freezing gives women the power to make more choices about her own body.

You may have heard that freezing your eggs in your 20s can help increase your chances of pregnancy down the line, but is there actually any truth to the claim? According to the American College of Obstetrics and Gynecologists (ACOG), there really is, given a woman’s peak fertility years span from the end of her teens to the end of her 20s. 

Read on to learn what you need to know about egg freezing success rates by age.

The best time to think about egg freezing is probably…now 

During these prime fertility years, we’re often focused on other things. In our 20s, we’re finishing school, launching our careers, traveling, having fun…starting a family may not even be a blip on your radar. Unfortunately, that also means that by the time you’re ready to get proactive about your fertility (or starting a family), your prime reproductive years may have already passed. 

This is why we believe that proactively thinking about your fertility is always a good idea for anyone looking to stay in control of their reproductive options. And one major barrier, until now, has been the accessibility and affordability of egg freezing. At Cofertility, we aim to change that, by partnering with local fertility clinics to create opportunities to freeze your eggs more affordably. 

Take our quiz to see what egg freezing options you may qualify for, including our Split program, where you can even freeze your eggs for free(!) if you give half to a family that can’t otherwise conceive and you qualify.

What are the egg freezing success rates by age?

We measure the “success” of an egg retrieval and later vitrification (the process of freezing and storing your eggs) in a couple of ways. Some of the major important milestones in a successful retrieval are: 

• The ability to collect high quality and healthy eggs 
• The ability to collect a large, but safe, number of eggs during a single cycle (between 10-20 is ideal)
• Whether collection takes place at an age where the eggs have a very good chance of surviving both the freezing and the warming process down the line 

Success rates for women in their 20s

Your 20s are by and large the best time to freeze your eggs, with 25 to 27 being the optimal age, according to a 2010 report from the CDC. The report found that eggs frozen during a woman’s 20s will have a 50 percent chance of resulting in a live birth per cycle, regardless of the age of the person carrying the pregnancy once the eggs are used. Women in this age range have fully finished developing (as opposed to someone in their late teens or early 20s who may still be growing and maturing) and are likely to have the healthiest and most robust eggs. 

Not only does it make it easier for eggs collected at this age to go on to become successful pregnancies, but it also makes it the most cost effective period, because you’re likely to get more eggs with fewer rounds of freezing than if your eggs were collected at a later age. 

Success rates for women in their 30s

Success rates in your 30s will depend on if you’re closer to 30 or 40, as well as your AMH levels. One study of 1,241 women found that the average number of eggs retrieved on the first egg freezing round was:

• 21 eggs for women under 35
• 17 eggs for women 35-37
• 14 eggs for women 38-40

Because women in their 30s tend to produce less eggs, at this age you may end up having to either settle for fewer eggs for freezing or undergo multiple rounds to collect enough eggs to have on hand for later implantation. As you can imagine, those costs can creep higher and higher the more rounds you endure. 

Now, you might be thinking: isn’t 14 eggs a lot?  It’s true that eggs retrieved from women under the age of 36 will have a 95 percent survival rate after being thawed.  

But more importantly, not all thawed eggs will become viable embryos and lead to a live birth. As this chart underscores, the probability of a live birth varies with the age of the woman trying to conceive and the number of mature eggs available. In short, the older the woman, the more eggs required to achieve a high probability of a live birth. 

A study in the Journal of Assisted Reproduction and Genetics further supports this point. For example, a woman under 35 will need 9 eggs to achieve a 70% chance of having at least one live birth. If you’re trying to conceive in your mid to late 30s, you may need double as many eggs to achieve that same 70% success rate. 

Success rates for women in their 40s

Because success rates drop significantly as you near the end of your 30s, it’s actually not recommended that women have their eggs frozen past the age of 38, according to the American Society for Reproductive Medicine (ASRM). 

But don’t let that news worry you. If you haven’t had your own eggs retrieved by this point, and are struggling to conceive, you still have some other options (including the use of donated eggs). 

Ask us anything

If you’d like help figuring out when to freeze your eggs, you can contact Cofertility for more information. While every woman’s fertility path differs, we can connect you with reputable clinics who can offer basic guidance about when the time is right for you to freeze your eggs during a consultation or dig into specifics by going through a preliminary exam in a provider’s office.

We understand that the timing may not be right for you to start a family right now, but that doesn’t mean it’s too early to start thinking about what choices will be available to you when that time comes. As you can see, a lot goes into preparing to freeze your eggs.  The earlier you consider your fertility, the more options you’ll have. 

Whether you decide to freeze or not, we’re here for you to answer any questions or talk through any concerns. 

According to the American College of Obstetrics and Gynecologists (ACOG), a woman’s peak fertility years are from their late teens to their late 20s. While these may be the easiest biological years for starting a family, between travel, work, school, life…at that point in your life, family planning might not be your top priority. 

Fortunately, thanks to modern medicine, you have some options. Egg freezing allows you to preserve your healthy eggs at any point in time, without committing to starting a family. Let's talk about what you need to know about freezing your eggs. 

Here’s what you need to know about the process

While there are some big hurdles to clear—like the expenses of going through the process and how (and where) you’ll store your eggs—freezing your eggs is a way to take more control of your future fertility health. 

That being said, it’s important that you think of freezing your eggs not as a guarantee, but rather, a proactive step you can take towards fulfilling potential long-term family planning goals. It is not an insurance policy, but it can help give you more options in the future. 

Research has found that freezing nine eggs while under age 35 leads to a 70% chance of a live birth (studies found that the average number of eggs retrieved for the same women is 18-21). And the more eggs you freeze, the better those odds get. There are always chances that your retrieval could fail, or that implantation down the line may not take. Still, egg freezing in your 20s does offer higher chances of success than having them retrieved at a later age.

Getting ready for retrieval 

Before you can freeze your eggs, you’ll want to ensure your body is producing as many eggs as possible. This means taking hormones that can help stimulate the follicles on your ovaries to produce a larger than normal quantity of eggs.

According to the Mayo Clinic, this may include taking multiple medications or injectables like: 

• Ollitropin alfa or beta (Follistim AQ, Gonal-f) 
• Menotropins (Menopur)
• Leuprolide acetate (Lupron Depot) 
• Cetrorelix (Cetrotide)
• hCG

Your doctor will monitor your progress with blood tests across the 10-14 day period. He or she will tweak any ovarian-stimulating medications you’re given to make sure your estrogen and progesterone levels are where they need to be for a successful retrieval. 

During these visits, you’ll likely also have vaginal ultrasounds. The doctor will use this to check on the development of the follicles where your eggs mature. It might sound overwhelming, but vaginal ultrasounds are usually painless. 

Then, when the time is right—typically 10 to 14 days after you’ve started your medications—you’ll check back in with your doctor and receive a final  injection of something called a human chorionic gonadotropin. This is the final kick to help your eggs mature and prepare them for retrieval. 

Retrieving your eggs

Retrieval is typically done while you’re under a light sedation at a fertility clinic. Your doctor will retrieve your eggs via vaginal ultrasound with suction to remove eggs from follicles. You’ll likely wake up feeling well rested while your medical team has done all of the heavy lifting for you!

While you won’t feel any pain during the procedure, a little soreness afterwards isn’t uncommon.  

Freezing and monitoring

After your procedure your eggs undergo a process called vitrification (AKA: freezing). This process relies on subzero temperatures to cool the eggs for storage. They’re normally stored along with a substance (like liquid nitrogen) that  keeps ice crystals from forming within the frozen eggs. They’re then placed in cold storage for 24/7 temperature monitoring.  

Storage timelines

You may be surprised to learn that your frozen eggs have no expiration date. In fact, in 2021 a child was born from an embryo frozen 25 years prior! Once your eggs have been successfully frozen they cease all biological activity, including aging and deterioration. 

While some countries may have limits on the length of time your eggs can remain frozen, this has not taken hold in the United States. This comes as good news for women who are hoping to freeze their eggs earlier in life and may need more years of frozen storage. 

Our Split program includes 10 years of free storage at a reputable long-term facility, where you'll have access to them whenever you choose to use them. Our Keep program also allows you to store your eggs for 10+ years, though note that the payment will be out of pocket each year. 

How much does it cost?

A lot of women worry about the price tag for freezing their eggs. One piece of good news is that as technology (and availability) of these solutions advances, costs are starting to come down.

Still, you can be looking at a bill for a few thousand dollars for the procedure alone—anywhere between $6,000 to $11,000—plus an annual bill between $300-$1,200 for storage, and up to $5,000 for medications. 

With Cofertility, however, we’ve worked with clinic partners to get you discounts on freezing (think: 75% off initial consults at certain clinics), storage (up to 80% off compared to reputable clinic freezing), and medications (about a 20% savings). 

For those who qualify, our Split program also offers the opportunity to freeze your eggs for free if you donate half of them to a family who can’t otherwise conceive. Yep, zero dollars. 

Split allows you to take control of your reproductive future (while offsetting the costs), and enables you to give someone else the greatest gift of all: a shot at parenthood. But at the end of the day, our mission is to empower women with reproductive choice. If you decide that freezing isn’t for you, we respect that. And most of all, we applaud you for taking this step towards exploring your options and learning more about your own fertility. 

Fertility is one of those topics that most of us are taught to ignore until we’re actively trying to get pregnant. But as more women take ownership of their reproductive plans—whether through egg freezing or simply learning more about their options—there’s growing interest in testing fertility early. The promise of data is appealing: if you could find out where you stand, maybe you could make clearer decisions about your timeline, your body, and your future.

But the reality is a bit messier. Yes, there are ways to test aspects of your fertility. But there’s also a lot that can’t be measured—at least not with the kind of certainty many people expect. Some tests give useful insights. Others are often misunderstood. And some questions still don’t have reliable answers, no matter how many labs you send your blood to.

In this article, we break down what you can and can’t learn about your fertility from today’s most common tests, especially if you’re in your 20s and thinking about options like egg freezing. We’ll also cover how to think about those results, what they actually mean for your future fertility, and what they don’t tell you.

You can test your ovarian reserve

Let’s start with the most talked-about test: Anti-Müllerian Hormone (AMH). This is a hormone produced by small follicles in your ovaries. The more of these follicles you have, the higher your AMH level tends to be. That makes it a useful proxy for ovarian reserve, or the estimated number of eggs you have left.

AMH will not tell you the exact number of eggs you have remaining, but it can be used to reliably predict how you’ll respond to fertility treatment. If you’re considering egg freezing, for example, a high AMH might suggest you’ll produce more eggs during a stimulation cycle, which could mean fewer cycles overall. A lower AMH might signal the opposite.

That said, AMH doesn’t predict whether you can get pregnant unassisted. It also doesn’t reflect egg quality. Many people with low AMH conceive without issues, and many people with high AMH still face fertility struggles.

In short: AMH is helpful for understanding how your ovaries might respond to medication, but it’s not a fertility report card. It’s a piece of the puzzle, not the whole picture.

You can check your follicle count, but it varies

Another test used to assess ovarian reserve is the antral follicle count (AFC), which is done via vaginal ultrasound. AFC is the number of small follicles in your ovaries that are visible on an ultrasound at the start of your menstrual cycle.

• Antral = fluid-filled, early-stage follicles
• Follicle = a tiny sac that contains an immature egg
• Count = how many are seen on the scan

AFC gives your doctor an idea of how many eggs your ovaries might be able to produce that month and helps estimate your overall ovarian reserve. Like AMH, this gives a snapshot of the eggs your body might recruit that month.

A higher count usually means a better response to egg freezing medications. It can also confirm whether your AMH results are in line with what your ovaries are actually doing.

But this test depends a lot on timing and technique. Different providers might get slightly different counts, and the number can fluctuate month to month. So while it’s useful when paired with other data, it’s not always consistent on its own.

You can evaluate your hormone levels, but they’re not always predictive

In addition to AMH, your provider may check other hormone levels at the start of your cycle (It is especially important that FSH and E2 are tested in the early follicular phase, as they cannot be reliably interpreted if done at a random phase of the cycle):

• FSH (follicle-stimulating hormone): Higher levels can suggest your ovaries are working harder to produce eggs, which may point to lower ovarian reserve.
• Estradiol (E2): This form of estrogen is measured alongside FSH to interpret the results accurately.
• LH (luteinizing hormone) and TSH (thyroid-stimulating hormone): These are sometimes included to rule out other hormonal conditions.

These blood tests are relatively easy to obtain and often included in a fertility workup. But their meaning can vary depending on when they’re taken and your cycle regularity. Like AMH, they don’t offer a yes-or-no answer about whether you’re fertile, they just add context.

There’s no test for egg quality 

This is where things get tricky. While you can estimate how many eggs you might have, there’s no current test that can measure the quality of your eggs. Egg quality mostly refers to whether an egg has the correct number of chromosomes. As people age, their eggs are more likely to develop abnormalities that make fertilization or a healthy pregnancy less likely.

Right now, the only way to assess egg quality is by making embryos. But even then, it’s difficult to know if the quality issue is from the egg, sperm, or a combination of both. 

Statistically speaking, younger people are more likely to have higher-quality eggs. But that’s a generalization, not a guarantee. Two people the same age can have different egg quality, and there’s no blood test that can measure this with accuracy.

So when people say, “Your egg quality declines with age,” they’re right. But when someone says, “You can test your egg quality,” they’re overselling it.

You can’t test how long you’ll be fertile

This is another common misconception. You might think that by testing your AMH or other hormones, you can predict how many fertile years you have left. Unfortunately, fertility doesn’t follow a strict countdown clock.

AMH gives a rough estimate of ovarian reserve, but it can’t tell you exactly when you’ll hit menopause, or when your eggs will stop being viable. Some people with high AMH experience early menopause. Others with low AMH get pregnant without issue. There’s too much individual variation to make long-term predictions with confidence.

Egg freezing can give you more options in the future—but it’s not a guarantee. The number and quality of frozen eggs, your age at the time of freezing, and your overall health all factor into how likely those eggs are to result in a baby later.

You can assess whether your fallopian tubes are clear

One test that often gets less attention in fertility conversations—but can be important—is the hysterosalpingogram (HSG). This is a specialized X-ray that looks at the inside of the uterus and fallopian tubes. It’s typically done by injecting a dye through the cervix and using imaging to see how the dye moves through the reproductive tract.

The goal is to check whether there are any blockages or structural issues that could prevent sperm and egg from meeting. If the dye flows freely through the fallopian tubes and into the abdominal cavity, that’s a good sign. If it doesn’t, it could indicate a blockage that might affect natural conception.

An HSG doesn’t give information about eggs, hormones, or ovulation, but it does offer a window into the physical pathways that make pregnancy possible. If you’ve had pelvic infections, endometriosis, or abdominal surgery in the past, your doctor may recommend this test as part of your fertility workup.

What about at-home fertility tests?

You’ve probably seen ads for at-home fertility tests promising insights into your reproductive future. Most of these kits check AMH, and some also offer hormone panels that include FSH, LH, and estradiol.

These can be helpful for getting started, especially if you’re not ready to visit a fertility clinic. But they’re not a substitute for a full medical evaluation. They also shouldn’t be used to make major decisions in isolation. If a test shows low AMH, it doesn’t mean you can’t get pregnant. And if it shows high AMH, it doesn’t mean you’re off the hook for thinking about fertility down the line.

Think of these kits as entry points—tools to start a conversation with a qualified provider, not definitive answers.

So what should you do with this information?

If you’re in your 20s, you’re in a good position to be proactive. Even though you can’t test everything, there’s value in learning what you can and starting the conversation early.

AMH and AFC can help you understand how your body might respond to treatment. Hormone panels can uncover issues you might not be aware of. And a consultation can give you space to ask questions and make a plan that fits your goals—even if that plan is just to wait and check back in a year.

It’s okay not to have all the answers. The idea isn’t to predict your future. It’s to give yourself more room to navigate it with intention.

Final thoughts

Fertility testing has come a long way, but it still has limits. You can measure ovarian reserve, hormone levels, and follicle counts. But you can’t test egg quality, predict exactly how long you’ll be fertile, or know for sure whether you’ll get pregnant naturally.

Still, having more information can be empowering—especially if it helps you make decisions on your own timeline. Whether you’re thinking about egg freezing or just want to understand your body better, asking questions now can open more doors later.

At Cofertility, we’re here to make those conversations easier, more transparent, and less intimidating. If you're considering egg freezing and want to understand what testing can (and can't) tell you, we’re happy to help you get started.

If you’re thinking about freezing your eggs, you’ve probably heard about the concept of “egg quality.” Maybe a friend mentioned it, or your doctor brought it up during a consultation. It’s one of those fertility buzzwords that can feel vague and hard to pin down. What does “egg quality” actually mean? And more importantly, is there a way to find out what yours is?

Egg quality refers to how likely an egg is to result in a healthy embryo and, eventually, a live birth. It’s not something we can measure directly—there’s no perfect test or score that tells you how “good” your eggs are. But we do have tools to assess your fertility potential, and there are signs and indicators that can give us insight into how your body is responding.

In this article, we’ll walk through what egg quality really means, why it matters, how it changes over time, and the testing options available today. We'll also talk about what to consider when thinking about fertility preservation—and how Cofertility can support you in taking next steps.

What we mean by “egg quality”

In medical terms, egg quality refers to the genetic and cellular health of an egg. A high-quality egg is one that has the right number of chromosomes and is capable of being fertilized, developing into a healthy embryo, and implanting in the uterus.

Eggs with abnormal numbers of chromosomes—called “aneuploid” eggs—are less likely to lead to a successful pregnancy. These eggs may not fertilize, may result in failed embryo development, or may lead to miscarriage if implantation does occur. In some cases, chromosomal abnormalities that originate in the egg can carry through to a developing embryo and lead to a live birth with a genetic condition. Down syndrome (Trisomy 21) is the most widely known example of this, but there are many other conditions that can arise from chromosomal abnormalities. This is why egg quality plays such a big role in fertility, even for people who are ovulating regularly or who feel perfectly healthy.

Unfortunately, there’s no simple blood test or ultrasound that can tell us with certainty which of your eggs are chromosomally normal. Egg quality can only truly be confirmed by creating embryos and performing genetic testing on them, which isn’t part of the typical egg freezing process. But there are other ways to estimate your fertility potential.

Age matters most

Of all the factors that impact egg quality, age is by far the most significant. People with ovaries are born with all the eggs they’ll ever have, and both egg quantity and quality decline over time.

Most people see a gradual decline starting in their early 30s, with a more noticeable drop-off around age 35. By age 40, a higher percentage of eggs are likely to be genetically abnormal. That doesn’t mean you can’t get pregnant or that all your eggs are “bad”—but it does mean fewer of your eggs may be capable of resulting in a live birth.

To put this age-related decline into perspective, here’s what the numbers actually look like:

• At age 25, approximately 20-25% of eggs may be chromosomally abnormal.
• At age 35, this increases to about 40-50%
• At age 40, that figure is up to roughly 70-80%
• At age 43, over 90% of eggs may be chromosomally abnormal

Egg quality is the main reason that IVF success rates drop with age, and why freezing your eggs earlier can increase your odds of having more usable eggs down the road.

Egg quantity vs. egg quality

It’s easy to confuse egg quantity with egg quality, especially since both tend to decline together. But they’re not the same thing.

Egg quantity refers to the number of eggs you have left—your “ovarian reserve.” The most commonly used tests to assess this are AMH (anti-Müllerian hormone) and antral follicle count, which can give us insight into your egg supply. These tests are useful for predicting how many eggs you might produce during a stimulation cycle, which is helpful when planning for egg freezing or IVF.

But these tests don’t tell us anything definitive about the quality of your eggs. It’s entirely possible to have a high AMH and still have a higher percentage of chromosomally abnormal eggs. On the flip side, someone with low ovarian reserve may still have good-quality eggs—it just may take more cycles to find them.

Can you test your egg quality?

Here’s where it gets tricky. There is no test that gives a direct readout of egg quality unless you’re creating and doing genetic testing on embryos. But here are some of the indirect ways we can get clues:

Age

As mentioned, this is the strongest predictor of egg quality. Most fertility specialists use age as a starting point when estimating how many eggs you may want to freeze for a future pregnancy.

Embryo development (in IVF)

If you go through IVF and fertilize your eggs, you can get information about how well your eggs developed into embryos. Some embryos can be biopsied and tested (PGT-A) to check for chromosomal normalcy. This gives a more direct window into egg quality—but it’s not part of standard egg freezing.

Ovarian reserve testing

While it doesn’t tell us about quality, ovarian reserve testing (AMH, FSH, AFC) gives us an idea of your egg quantity. If your numbers are unexpectedly low for your age, it may be worth exploring your optionsmore quickly, especially if you’re considering freezing your eggs.

Cycle response

If you go through an egg freezing cycle, how your body responds to stimulation medications (how many eggs mature, hormone levels during the cycle, etc.) can also offer insight. At Cofertility, we support you through every part of the cycle and help explain what your results might mean.

What affects egg quality besides age?

While age is the biggest factor, other things can also impact egg quality over time. Some are within your control, others aren’t.

• Smoking, whether that’s nicotine or marijuana, is consistently linked to lower egg quality and earlier menopause.
  
• Certain medical conditions, like PCOS, endometriosis, or autoimmune disorders, may affect egg health.
  
• Chemotherapy or radiation treatments can damage eggs or reduce ovarian reserve.
  
• Environmental exposures to endocrine-disrupting chemicals may play a role, although research is still ongoing.

There's growing interest in how lifestyle, diet, and supplements may support egg health. While there's no magic food or pill that guarantees higher-quality eggs, taking care of your overall health—getting enough sleep, avoiding smoking, managing stress, and maintaining a balanced diet—can support your fertility.

How Cofertility can help

If you’re thinking about freezing your eggs, understanding your fertility is the best place to start. At Cofertility, we’re here to guide you through the process with clarity and support—not pressure.

Through our Split and Keep programs, we offer egg freezing in a way that puts you in control:

• With our Split Program, you can freeze your eggs for free when you donate half to a family who can’t otherwise conceive. This model attracts people motivated by shared values—not just financial incentives—and gives donors a way to preserve their own fertility without the high cost.
  
  
• Our Keep Program is designed for those who want to freeze and keep all of their eggs. We help you navigate the process, connect you with partner clinics, and offer a support team to answer your questions at every step.
  

Our team includes experienced nurses (like me), fertility doctors, and donor coordinators who are here to help you feel informed—not overwhelmed. Whether you're ready to move forward or just want to ask questions, we’re here when you’re ready.

Final thoughts

There’s a lot of noise out there about egg quality—and it can be hard to separate fact from fear. While there’s no single test to measure it, your age, hormone levels, and cycle response can all offer clues. If you’re curious about your fertility, or planning ahead for the future, taking steps to learn more now can give you more options later.

Freezing your eggs isn’t the right decision for everyone. But if you’re considering it, Cofertility can help you do it in a way that’s empowering, transparent, and supported by people who care.

You deserve to make these decisions with clarity and confidence—not confusion. Let us help you get there.

Egg freezing has become an increasingly popular option for those looking to preserve their fertility, whether for medical reasons, personal timing, or future family planning. The process, known as oocyte cryopreservation, offers hope and flexibility, but it’s not without its uncertainties. One common question we hear is: Why do some frozen eggs not survive the thaw? It’s a great question, and understanding the answer requires a look at the science behind egg freezing, the challenges of the process, and the factors that influence success rates.

In this article, we’ll explore the reasons why some eggs don’t make it through the thawing process, what happens during freezing and thawing, and how advancements in technology are improving outcomes. We’ll also discuss what you can do to set yourself up for the best possible results. While egg freezing is a powerful tool, it’s important to approach it with realistic expectations and a clear understanding of the process.

The basics of egg freezing and thawing

Egg freezing involves carefully extracting eggs from the ovaries, cooling them to sub-zero temperatures, and storing them for future use. The goal is to preserve the eggs in their current state, effectively hitting the “pause” button on those specific eggs. When you’re ready to use them, the eggs are thawed, fertilized, and transferred as embryos in the hopes of achieving a pregnancy.

The freezing process itself has come a long way. In the past, a method called slow freezing was used, but it often led to the formation of ice crystals, which could damage the eggs. Today, most clinics use a technique called vitrification, which flash-freezes the eggs so quickly that ice crystals don’t have time to form. This method has significantly improved survival rates, but it’s not foolproof.

What percent of eggs make it through the thaw?

What what are the chances your eggs will survive the thaw? The answer isn’t straightforward, as survival rates can vary based on several factors, including the clinic’s expertise, the age of the eggs, and the freezing method used. 

Overall, the survival rate when thawing frozen eggs using vitrification is 95%. This is a significant improvement over older methods like slow freezing, which had survival rates closer to 75%. Vitrification’s rapid cooling process minimizes the risk of ice crystal formation, which is a major cause of egg damage during freezing and thawing.

Why some eggs don’t survive the thaw

In general, thaw rates are very good these days. However, they aren’t the same for everyone. Even with the advancements in vitrification, not all eggs make it through the thawing process. Here are some of the key reasons why:

• The fragility of eggs: Human eggs are among the largest cells in the body and contain a high amount of water. This makes them particularly sensitive to temperature changes. During freezing and thawing, the egg’s structure can be compromised, leading to damage that prevents it from surviving.
• Age and quality of the eggs: The quality of the eggs at the time of freezing plays a significant role in their survival. Younger eggs, typically from women in their 20s and early 30s, tend to have better survival rates than those from older individuals. This is because younger eggs are more likely to have intact DNA and cellular structures, which are better able to withstand the stresses of freezing and thawing.
• Laboratory quality: The process of freezing and thawing eggs is highly technical and requires precision. Even small errors in the timing, temperature, or handling of the eggs can impact their viability. Clinics with experienced embryologists and state-of-the-art equipment tend to have higher success rates.

Survival rates can and do vary between clinics. Clinics with highly skilled embryologists and advanced technology often report higher success rates. Some top-tier fertility clinics report near perfect survival rates for eggs frozen using vitrification. This is why it’s so important to choose a clinic with a strong track record and transparent data.

What happens after the eggs are thawed

Surviving the thaw is just the first step. After thawing, the eggs must be fertilized, develop into healthy embryos, and successfully implant in the uterus. Estimates vary, but according to UCLA Health the overall chance of a pregnancy is between 4-12% per oocyte per thawed egg, depending on factors like age, sperm quality, and clinic expertise. This means that while most eggs survive the thaw, not all will result in a successful pregnancy.

To put this into perspective, if you freeze 10 eggs, you might expect 8-9 to survive the thaw. Of those, only a portion may fertilize and develop into viable embryos. Your fertility doctor can work with you to determine the ideal number of eggs to freeze to increase the likelihood of achieving a pregnancy in the future.

While these numbers might feel daunting, it’s important to remember that egg freezing is still one of the most effective ways to preserve fertility, especially for those who freeze their eggs at a younger age. Advances in technology and clinic expertise continue to improve outcomes, offering hope and options for those planning for their future families.

What you can do to improve your chances

While some factors, like age, are beyond your control, there are steps you can take to improve your chances of success:

• Choose the right clinic: Research clinics thoroughly and choose one with a strong track record in egg freezing and thawing.
• Freeze your eggs sooner rather than later: The younger you are when you freeze your eggs, the better their quality and survival rate.
• Follow your clinic’s instructions: During the egg retrieval process, follow your clinic’s guidelines for medications, diet, and lifestyle to ensure the best possible egg quality.
• Consider undergoing multiple cycles: The more eggs you freeze, the higher your chances of having viable eggs after thawing. 

Read more in How to Increase Egg Freezing Chances of Success

The future of egg freezing technology

While egg freezing has come a long way, there’s still room for improvement. Researchers are continually working on new techniques to improve survival rates and make the process more reliable. For example, some studies are exploring the use of different cryoprotectants or modified freezing protocols to further reduce the risk of damage.

Advances in artificial intelligence and machine learning are also being applied to fertility treatments. These technologies could help embryologists better predict which eggs are most likely to survive freezing and thawing, leading to more personalized and effective treatments.

Final thoughts

Egg freezing offers hope and flexibility for those looking to preserve their fertility, but it’s not without its challenges. Understanding why some eggs don’t survive the thaw can help you make informed decisions and set realistic expectations. By choosing a reputable clinic, freezing your eggs at a younger age, and staying informed about the process, you can improve your chances of success.

While the science of egg freezing continues to evolve, it’s important to remember that every individual’s experience is unique. If you’re considering egg freezing, take the time to consult with a fertility specialist, ask questions, and weigh your options carefully. With the right information and support, you can make the best choice for your future.

Freeze your eggs with Cofertility

We’d love the opportunity to support you on your egg freezing journey.

Through our Split program, qualified freezers can freeze their eggs for free when donating half of the eggs retrieved to a family who can’t otherwise conceive.

Through our Keep program — where you keep 100% of eggs retrieved for your own future use — we offer exclusive discounts on expenses, such as frozen egg storage. Keep members also still gain free access to our Freeze by Co Community, a safe space for those engaging in the egg freezing process (or gearing up for it) to connect and lean on each other.

By making egg freezing easier and more accessible, our programs further strengthen the American Society of Reproductive Medicine (ASRM)’s Committee Opinion that egg freezing can help promote social justice and strengthen gender equality.

It’s no secret that egg freezing is a significant journey that demands time, money, and energy. Having gone through IVF twice — which involves the same egg retrieval process — I know first-hand the importance of being as prepared as possible leading up to your retrieval. From personal experience and extensive research, I’ve created a detailed three-month roadmap to help you optimize your preparation for egg freezing. I wish I had access to this kind of guide when I was starting my fertility treatments! 

In order to help you prioritize, this list is organized by “must-do’s” vs. “nice-to-haves”. While we can’t significantly affect our egg quality, at the very least, these simple tips could hopefully help enhance your egg quality and quantity in some capacity. And at most, they’ll also provide some peace of mind so you feel calm, ready, and empowered to take on this incredible thing you’re doing for your fertility future. 

Month 1: laying the foundation

If you’re still a few months out from your retrieval, you have the luxury of time to make real lifestyle shifts that might benefit your outcome. Let’s make the most of it! 

Must-dos

Nutrition adjustments 

Focus on a balanced diet rich in antioxidants, which can help protect eggs from oxidative stress. Integrating more fruits, vegetables, whole grains, and healthy fats can improve overall reproductive health. Key nutrients to focus on include:

• Folate: Recent studies indicate the importance of folate intake when it comes to cycle regulation, ovarian function, and pregnancy preparation. Folate can be found in leafy greens, citrus fruits, and legumes. Note: folate is a naturally occurring nutrient, while folic acid is a synthetic version of folate added to fortified foods and supplements.
• Omega-3 fatty acids (DHA): Found in fish oil and flaxseeds, these nutrients support cellular health, and improve ovarian function, and some data suggests that improved omega-3 intake can enhance egg quality, though these studies are primarily limited to women undergoing treatment for infertility. 
• Hydration: Drinking enough water is important for everyone, but if you’re about to undergo an egg freezing cycle, consider upping your daily water intake to 2-3 liters per day in order to remain properly hydrated.

For a deeper dive into dietary tips prior to egg freezing, check out our guide here. 

Medication changes

In addition to adding new supplements into your routine, you should connect with your doctor about what supplements or medications to adjust leading up to your cycle. Your doctor may have you change a dosage or pause a certain medication altogether. For more on which medications you might need to adjust during an egg freezing cycle, click here.

Nice-to-haves

Upgrade your supplement regimen 

While you should not begin a supplement regimen without discussing it with your doctor first, here are a few supplements worth talking to your doctor about as you prepare for egg freezing:  

• CoQ10: Several studies indicate that CoQ10 supplementation can be associated with increased egg volume, improved fertilization rates, and improved embryo development rates.
• Myo-inositol: This substance can improve insulin resistance and ovarian function, with studies supporting its role in enhancing egg quality.
• Vitamins B6, B12, E, and K2: All often found in prenatal vitamins like the one we linked, these are essential for cellular function and embryo development down the line.

For a full list of recommended supplements for gearing up for egg freezing, click here. 

Moderate exercise

Studies on the relationship between exercise and fertility are limited, but the endorphins you’ll feel as a result of regular movement won’t hurt. Be careful to avoid excessive, high-intensity workouts as you get closer to your retrieval as this can negatively affect your reproductive cycle. And, during the ovarian stimulation phase right before your retrieval, you’ll need to hold off on high-intensity workouts altogether to prevent ovarian torsion. 

Self-care essentials

Start stocking up on items like a good ice pack or heating pad for injections, comfy clothes for bloating, and cozy socks (those stirrups can get chilly!). 

Month 2: enhancing egg quality

As you get closer to your egg freezing cycle, continue managing the adjustments you’ve begun to make to your lifestyle. You’ll also start communicating more regularly with your clinic — beginning medications if prescribed, or starting to visit the office more for assessments and monitoring. 

Must-dos

Increased monitoring

While you won’t ramp up frequent office visits until closer to your cycle, expect to visit your fertility clinic a bit more frequently than before. You’ll usually need to do some bloodwork and/or ultrasound before finalizing a medication plan and timing. This may include starting birth control to bring your cycle back to baseline before kicking things off. 

Stress management

While stress might feel unavoidable, high stress levels can disrupt hormonal balance. Aim to integrate stress management activities or strategies into your daily routine in some capacity. This might include things like yoga or meditation, or even learning some quick deep breathing techniques to better navigate stressful moments throughout your day. 

Nice-to-haves

Acupuncture

If you’ve never tried acupuncture, now is a good time to start. Some studies suggest acupuncture can improve blood flow to the ovaries and enhance fertility outcomes, but honestly, the jury is still out. Our POV? There’s no downside, so if you can make it work and enjoy it, it could be worth a try. You can read more here for a deeper dive into acupuncture for egg freezing, and some insights based on my personal experience.  

Sleep quality

Studies suggest aiming for about 8 hours of quality sleep per night to help regulate hormone cycles, though it’s unclear if this directly affects egg quality or quantity. 

Reduce endocrine disruptor exposure

You may have heard about “endocrine disruptors,” which are chemicals that can interfere with your endocrine (hormonal) system and the reproductive and other biological processes it regulates. Unfortunately, endocrine disruptors are not fully regulated in the United States, and can be found in certain beauty products, plastics, and more. Consider switching to cleaner products and glass containers as you gear up for your egg freezing cycle. 

Month 3: final preparations

The final month is about adhering to prescribed medical treatments, minimizing exposure to harmful substances, and ensuring you are as relaxed and supported as possible as you approach your retrieval.

Must-dos

Adjust and organize your medications 

Spend some time leading up to your retrieval getting your medications organized, including syringes, alcohol pads, gauze, and the medication themselves. You could even use a special box or cute caddy. As your doctor provides final adjustments to your medication protocol, you’ll also want to write our your daily medication plan in a way that’s easy to follow. I personally had luck with a printed-out calendar view, with AM and PM medications listed out and color coded. This gave me a small sense of control over this time, which can feel a bit chaotic! 

Avoid harmful substances

While the link between caffeine and fertility is not clear, it’s probably a good idea to keep the jitters to a minimum as you gear up for your retrieval. Alcohol intake should also be reduced, and smoking should be ceased entirely as it can be detrimental to reproductive health. 

Nice-to-haves

Secure your support system 

Communicate your upcoming egg freezing journey on a need-to-know basis. That includes sharing with managers and/or coworkers any necessary scheduling shifts, but it also means connecting with trusted family members, friends, or even online communities (like ours!) about what’s about to happen. 

Freezing your eggs is a big deal, and besides needing someone to escort you home after the retrieval, you’ll want some shoulders to lean on — even virtually. 

Set your medication alarms

In addition to writing out your medication plan, setting alarms on your phone for medication times can help keep you sane during your egg freezing cycle. If you’ve got lots going on, setting alarms can be crucial as you’ll need to take medications at specific times throughout the day. 

How Cofertility can support your journey

At Cofertility, we understand that egg freezing is a significant emotional and financial decision. That's why we offer more affordable and even free egg freezing options for women who choose to donate half of their eggs retrieved to another family struggling with conception. 

Ready to begin your egg freezing journey? Take our quiz to discover how we can best support you, and learn about your eligibility for free egg freezing.

Embarking on your egg freezing journey can be an incredibly transformative period in your life. With the right preparation, informed choices, and supportive care, you can approach this phase with confidence and optimism. We're here to ensure that every step you take is grounded in knowledge and surrounded by support.

If you're considering egg freezing, or have already frozen your eggs, you may have encountered terms like "mature" and "immature" eggs. Understanding the distinction between these two types of eggs can help you grasp the egg freezing process and its potential outcomes. 

This article will delve into the biological differences between mature and immature eggs, their significance in egg freezing, and what this means for your fertility journey.

The basics of egg development

To comprehend the difference between mature and immature eggs, it's helpful to understand the process of egg development, also known as oogenesis. This process begins before birth and continues throughout a woman's reproductive years.

Primordial follicles: The starting point

At birth, a female's ovaries contain approximately 1-2 million primordial follicles, each housing an immature egg (oocyte). These primordial follicles represent the total pool of potential eggs a woman can produce in her lifetime.

The menstrual cycle and egg maturation

During each menstrual cycle, a subset of these primordial follicles begins to grow and develop. However, typically only one follicle (occasionally more) will fully mature and release an egg during ovulation. The rest of the developing follicles will naturally degenerate.

During egg freezing

The egg freezing process aims to optimize this natural cycle by using medication to produce multiple mature eggs in one cycle, significantly increasing the number of mature eggs available for freezing compared to a natural menstrual cycle.

What are mature eggs?

Mature eggs, also known as secondary oocytes or metaphase II (MII) oocytes, have completed the first meiotic division and are ready for fertilization. 

Mature eggs several distinct features:

• First polar body: The most obvious sign of a mature egg is the presence of the first polar body in the perivitelline space (the area between the egg and its outer shell, called the zona pellucida).
• Size and shape: A mature egg is typically round and of a standard size. However, the study linked above notes that egg size can vary, and this variation doesn't necessarily affect fertilization or embryo quality.
• Cytoplasm: Ideally, a mature egg should have a homogeneous (evenly distributed) cytoplasm. However, slight variations in cytoplasmic appearance are common and may not indicate any problems.
• Zona pellucida (ZP): This is the outer shell of the egg. In a mature egg, it should be clear and of normal thickness.
• Perivitelline space: This is the space between the egg itself and the zona pellucida. In a mature egg, this space should be of normal size, not too large or too small.
• Meiotic spindle: While not visible under regular microscopy, specialized techniques can reveal the presence of a meiotic spindle, which is crucial for proper chromosome alignment.
• Absence of certain features: Mature eggs should not have a visible nucleus (called a germinal vesicle), which is a sign of immaturity.

While these are the ideal characteristics, many eggs retrieved in egg freezing may show one or more variations from these "ideal" criteria. Some variations are considered normal and don't necessarily impact the egg's ability to be fertilized or develop into a healthy embryo. However, certain features, like the presence of smooth endoplasmic reticulum clusters, are considered potentially problematic.

What are immature eggs?

Immature eggs, also called primary oocytes or immature ovum, are eggs that have not completed the process of meiosis, a specialized type of cell division necessary for reproduction. 

During egg freezing, not all eggs will mature, and some will be retrieved that are considered immature. These eggs are generally smaller than mature eggs, and cannot be fertilized by sperm today.

Immature eggs fall into two categories:

1. Germinal vesicle (GV) stage eggs: These are the most immature and are identifiable by the presence of a visible nucleus.
2. Metaphase I (MI) stage eggs: These eggs have begun the maturation process but haven't completed it. They lack both a visible nucleus and a polar body.

While immature eggs are usually not frozen, at Cofertility we try and ask clinics to keep them for our members. It is our hope that in the future, these immature eggs will be able to be reliably matured in the laboratory. 

How many eggs will be mature?

On average, approximately 80% of eggs retrieved during egg freezing are mature, while 20% are immature. 

Several factors can influence the number of mature eggs retrieved:

1. Age: Younger women typically produce a higher percentage of mature eggs. As women age, not only does the total number of eggs decrease, but the proportion of mature eggs may also decline.
2. Ovarian stimulation protocol: The medications and dosages used during the stimulation phase can affect egg maturity. Your fertility doctor will tailor the protocol to optimize the number of mature eggs retrieved.
3. Timing of the trigger shot: The timing of the final maturation trigger is critical. If given too early or too late, it can affect the maturity of the eggs at retrieval.
4. Individual response to stimulation: Every woman's ovaries respond differently to stimulation. Some may produce a higher percentage of mature eggs, while others may have more immature eggs.
5. Underlying fertility conditions: Certain conditions, such as polycystic ovary syndrome (PCOS), can affect egg maturity rates.

During the egg retrieval process, the embryologist will examine each egg under a microscope to determine its maturity. The presence of some immature eggs is normal and expected. In fact, having a mix of mature and immature eggs can be a sign of a healthy response to ovarian stimulation.

While it's natural to focus on the number of mature eggs retrieved, it's important to remember that quality matters as much as quantity. A smaller number of high-quality mature eggs can be more valuable than a larger number of lower-quality eggs.

What’s the difference between immature and mature eggs?

Today, mature eggs are the gold standard. Here's why:

Higher survival rates after thawing

Mature eggs have completed critical developmental stages, making them more resilient to the freezing and thawing process. They're better equipped to withstand the physical stress of vitrification (flash-freezing) and subsequent warming.

Greater potential for fertilization

Once thawed, mature eggs are immediately ready for fertilization. They've already undergone the necessary cellular changes to allow for the entry and processing of sperm DNA.

Improved embryo development

Eggs that were mature at the time of freezing tend to result in higher-quality embryos after fertilization. This can lead to better chances of successful implantation and pregnancy.

What Split Members should know

If you’re part of our Split program, where members freeze their eggs for free when donating half to a family that otherwise can’t conceive, there are a few things you should know:

• You will receive immediate ownership of half of the mature eggs retrieved. If there is an odd number, the intended parent will keep the extra egg.
• You also receive 100% of immature eggs retrieved to the extent clinic policy allows (not all clinics are able to cryopreserve GV eggs).
• We cover ALL egg freezing expenses and 10 years of storage. Of course you can get the eggs sooner if needed.

The reason we give 100% of immature eggs to the Split Member (egg donor) is because, while it’s not possible today, we hope that in the future that embryologists will be able to mature immature eggs in the lab. 

Summing it up

Grasping the difference between mature and immature eggs is helpful to understanding the egg freezing process and setting realistic expectations. While mature eggs are the primary goal of egg freezing, the presence of some immature eggs is normal and doesn't necessarily indicate a problem.

As you consider or proceed with egg freezing, remember that your fertility doctor is your best resource for personalized information. They can provide insights into your individual situation, explain your results, and help you understand what they mean for your fertility preservation goals.

We wish you all the best!

If you're participating in Cofertility’s Split Program, where you freeze your eggs for free when donating half to another family that can't otherwise conceive, a necessary step in the process is carrier screening. Carrier screening is a type of genetic test that can tell you whether you carry a gene for certain genetic disorders. This critical step ensures the best possible outcomes for both you and the recipient family.

You may have some questions or find yourself wondering about its necessity, what it involves, and how the results could affect you and the intended parents. This article aims to clarify the process and provide you with essential information to help you feel informed and confident.

By understanding the role of genetic testing, you'll be better equipped to make informed decisions and communicate effectively with healthcare providers, genetic counselors, and anyone else.

Why is genetic testing required for egg donors?

The American Society for Reproductive Medicine (ASRM) has developed guidance for the screening of egg donors that most clinics and egg donation agencies (like ours) follow. This  guidance includes genetic risk assessment, and specifically carrier screening. Why is carrier screening important?

Carrier screening plays an important role in ensuring the health of any potential children resulting from the donation. Many genetic conditions are recessive, meaning a person can carry the gene without showing symptoms. By screening egg donors, we can identify these genetic variants and minimize the risk of passing on inherited disorders.

Importantly, this genetic information is also valuable for you as the donor. It provides insights into your own genetic makeup, which can be beneficial for your future family planning. If you discover you're a carrier for a particular condition, you can make informed decisions about your own reproductive health and discuss potential risks with your healthcare provider.

Additionally, genetic testing helps in the matching process between donors and intended parents. By understanding the genetic profiles of both parties, we can ensure compatibility and reduce the risk of passing on inherited disorders. This contributes to the overall success and safety of the egg donation process.

What is carrier screening?

Carrier screening is a type of DNA test that looks for variants (mutations or DNA changes) in certain genes. These genes are associated with "recessive" conditions, which means a person needs to inherit two copies of the variant gene - one from each parent - to develop the condition.

Understanding autosomal recessive inheritance

We inherit two copies of every gene - one from the egg provider and one from the sperm provider. Autosomal recessive diseases occur when someone has a gene variant in both copies of a certain gene. Individuals who carry only one variant for a recessive disease are called "carriers" and generally don't have any symptoms of the disease.

X-linked inheritance

Some conditions are linked to genes on the X chromosome. Females typically have two X chromosomes, while males have one X and one Y chromosome. For X-linked conditions, males who have a variant are usually affected, while females are typically carriers. This is important in egg donation because a female carrier has a chance of passing the condition to male offspring.

The testing process

Genetic testing for egg donors typically involves the following steps:

1. Sample collection: Either a blood draw, saliva, or cheek swab sample is taken.
2. Laboratory analysis: The sample is sent to a specialized genetics laboratory for analysis.
3. Waiting period: Results usually come back within 2-3 weeks.
4. Result interpretation: A healthcare provider or genetic counselor will interpret the results for you, at no cost to you.

Today’s carrier screening tests often examine more than 100 genes associated with various inherited conditions. This comprehensive approach has replaced older methods that only tested for conditions common in specific ethnic groups.

What can you learn from genetic testing?

Genetic testing, particularly carrier screening, can provide you with a wealth of information about your genetic makeup. Primarily, you'll learn about your carrier status for the genetic conditions included in the panel. Being a carrier means you have one copy of a gene variant associated with a particular condition, but you don't have the condition yourself. This information is helpful for understanding potential reproductive risks, both for your role as an egg donor and for your own future family planning.

In addition to carrier status, genetic testing can sometimes offer insights into your ethnic background. Certain genetic variants are more common in specific populations, which can provide clues about your genetic ancestry. While this isn't the primary purpose of the screening, it can be an interesting secondary finding for some individuals.

Occasionally, carrier screening might reveal unexpected information about your own health. For instance, being a carrier for certain conditions might be associated with an increased risk of developing related health issues. While rare, these findings can be valuable for your long-term health management.

Furthermore, genetic testing results can sometimes shed light on your family health history. You might gain a better understanding of why certain conditions run in your family or discover previously unknown genetic factors that could be relevant to your relatives.

While genetic testing provides valuable information, it doesn't predict everything about your health or your potential offspring. Many factors beyond genetics contribute to overall health and development. Nonetheless, the insights gained from genetic testing can be a powerful tool for making informed decisions about your health and your participation in the egg donation process.

Types of conditions included in carrier screening

Carrier screening generally tests for genes associated with:

• Moderate to severe childhood diseases
• Conditions that lead to a shorter life expectancy
• Disorders causing disability
• Diseases with limited or no treatment options

Some examples of conditions often included in carrier screening are:

• Cystic fibrosis
• Spinal muscular atrophy
• Thalassemia/hemoglobinopathy
• Fragile X syndrome
• Tay-Sachs disease
• Sickle cell anemia

Specific conditions tested can vary depending on the screening panel used.

How genetic test results affect your donor status

In most cases, being a carrier for a genetic condition won't prevent you from being an egg donor. The key is ensuring that your genetic profile doesn't match with any variants carried by the intended parents or sperm provider.

However, there are some rare situations where a positive carrier screen might affect your eligibility, like if you're a carrier for a serious X-linked condition, like Fragile X.

What does a negative carrier screen mean?

A negative or normal screen means that no changes were found in any of the genes on the panel tested by the lab. While this is good news, it's important to remember that no test is perfect. Carrier screening doesn't test for all recessive diseases and can't identify all carriers for the diseases that were tested.

What does a positive carrier screen mean?

A positive carrier screen means that you have been identified as a carrier for one or more genetic conditions tested in the screening. Being a carrier doesn't mean you have the condition yourself. Instead, it means you have one copy of a gene variant associated with a particular condition.

Being a carrier is actually quite common. Most people are carriers for at least one genetic condition, and this usually doesn't affect their health. However, it can have implications for reproductive planning, both for egg donation and your own future family planning.

If you receive a positive result on your carrier screen, there's no need to worry. We cover the cost of talking to a genetic counselor to help you understand what your test results mean. The genetic counselor can explain your results in detail, discuss any potential implications, and answer any questions you may have. This ensures that you have a clear understanding of your genetic status and can make informed decisions moving forward.

Remember, a positive carrier screen doesn't necessarily disqualify you from being an egg donor. The implications depend on the specific condition and the genetic status of the intended parents or sperm provider. The genetic counselor and your Cofertility Member Advocate will guide you through what your results mean for your participation in the egg donation program.

Summing it up

Genetic testing is a required part of the egg donation process. It is a tool to ensure the best possible outcomes for all involved. The information you gain can be valuable not only for your role as an egg donor but also for your own future family planning.

As you go through this process, it's normal to have questions or concerns. Don't hesitate to ask your fertility doctor, genetic counselor, or your Cofertility Member Advocate for clarification or support. They're there to guide you through this important step in your egg donation journey.

Remember, being a carrier for a genetic condition is common and doesn't necessarily impact your overall health or ability to be an egg donor. By participating in genetic testing, you're contributing to informed decision-making and potentially helping create families while gaining valuable insight into your own genetic makeup.

If you just started researching egg freezing, you might feel like you’ve been introduced to a whole new language. Whether clinical in nature or just shortened slang, with egg freezing comes its own terminology. And even if you’ve already educated yourself on what’s involved with egg freezing, chances are, you’ll come across an acronym you’ve never heard of. 

Fear not. Below, you’ll find a comprehensive list of acronyms, abbreviations, and terms you should know when diving into an egg freezing cycle. Read this, and soon you’ll rattle off egg freezing lingo like a pro. 

Hormones and general fertility 

• AMH: One of the first hormones your reproductive endocrinologist will investigate, Anti-Müllerian Hormone is measured early in a woman’s cycle to determine her ovarian reserve. A higher AMH level correlates to a higher ovarian reserve, or in other words, more eggs.
• CD: "Cycle day"—or the day of one's menstrual cycle, with CD1 = the first day of a period. Understanding your cycle length is super important, as it may indicate your most fertile window of dates. It will also help you determine any irregularities to consider as you embark on an egg freezing cycle. 
• DPO: "Days past ovulation." In a typical menstrual cycle, women can expect their period at 14DPO.
• Dx: Diagnosis, the medical identification of a condition or issue affecting fertility, which may impact decisions regarding egg freezing and related treatments.
• E2: Estradiol, a female hormone that's produced by ovarian follicles and determines how well a woman is responding to controlled ovarian hyperstimulation with fertility drugs. If you're freezing your eggs, you’ll have several routine monitoring appointments that include ultrasounds and bloodwork that measures estradiol levels. The higher the estradiol, the more follicles that are likely developing and (fingers crossed) the more eggs that may be retrieved.
• FSH: Follicle stimulating hormone, a hormone released from the pituitary gland to stimulate the ovaries or testicles. When getting an initial fertility workup, you'll get tested for your existing FSH. If you're taking FSH as a drug as part of your egg freezing protocol, it's also known in the United States as Follistim, Gonal-F or Bravelle.
• hCG: Human Chorionic gonadotropin, a hormone produced by an implanting embryo. If this hormone is present in a woman's blood, it indicates a possible pregnancy. It can also be given to women undergoing an egg freezing cycle to trigger ovulation right before a retrieval procedure.
• LH: Luteinising Hormone, a hormone released by the pituitary gland to stimulate the gonads (ovaries and testicles). If you're freezing your eggs, you'll have levels of this hormone measured often via bloodwork in order to determine ovulation timing.
• LMP: "Last menstrual period," or the start date of a woman's last menstrual period.
• MII: Metaphase II, the stage of egg maturation where the egg is ready for (hypothetical) fertilization, with chromosome alignment necessary for successful embryo development.
• PCOS: "Polycystic ovarian syndrome," a condition where the ovaries develop many small cysts, which results in irregular periods and ovulation. It can contribute to future infertility, so if you know you have PCOS, regardless of whether you’re freezing your eggs or not, chat with a reproductive endocrinologist to ensure a safe and healthy plan.
• TSH: Thyroid stimulating hormone, a hormone produced by the pituitary gland meant to stimulate the release of thyroid hormone by the thyroid gland. Recent research has suggested that slightly low TSH may associate with fertility challenges.

Egg freezing 

• AFC: “Antral follicle count,” a count of the number of small follicles in a woman's ovaries, seen via ultrasound early on in her cycle. Used to measure ovarian reserve, you'll have a lot of these if you're freezing your eggs to monitor how you're responding to ovary-stimulating medication.
• ART: “Assisted reproductive technology,” including any procedure involving egg retrievals and manipulating eggs and sperm outside the body. It includes things like egg freezing, gamete intrafallopian transfer (GIFT), in vitro fertilization (IVF), and zygote intrafallopian transfer/tubal embryo transfer (ZIFT/TET). 
• BCP: Birth control pills. If you’re freezing your eggs, your doctor may prescribe these as part of a medicated cycle in order to regulate the timing
• COH: “Controlled ovarian hyperstimulation,” when several follicles mature simultaneously in response to fertility drug treatment. The key word here is controlled. Your follicle growth will be carefully monitored by your doctor, who will adjust your medication protocol accordingly to stimulate or halt further growth.
• ER: "Egg retrieval" — not "emergency room!" An ER will be performed as part of an egg freezing cycle, and may also be referred to as a VOR (“Vaginal Oocyte Retrieval”).
• IM: Intramuscular, a method of injecting medication directly into a muscle. This method is often used for hormone treatments during the egg freezing process.
• OC: “Oocyte Cryopreservation,” which is another term for egg freezing. 
• OHSS: “Ovarian hyperstimulation syndrome,” a condition where the ovaries become excessively swollen and painful due to the overproduction of eggs from fertility medications. This is very rare, but can happen.
• REI: "Reproductive endocrinologist," or a doctor who specializes in treating male and female fertility.
• SD1: “Stimulation Day 1,” or the first day of medication administered to stimulate the ovaries for egg production during the egg freezing process.
• SQ: Subcutaneous (also abbreviated as SC), a method of injecting medication into the fatty tissue just under the skin, commonly used for administering fertility hormones during an egg freezing cycle.
• TVUS: “Transvaginal Ultrasound,” an imaging technique used to visualize the ovaries and follicles internally, providing information about egg development and ovarian health. If you’re undergoing an egg freezing cycle, you’ll have a lot of these, but they are quick and painless. 

Egg donation

• DE: “Donor eggs,” or eggs provided by another woman to be fertilized with sperm and transferred to the uterus of an intended parent or gestational carrier.
• IP: “Intended parent,” which is a person who becomes the legal parent of a child born through third party reproduction.

If you’re feeling totally overwhelmed by all that’s involved with egg freezing, we’ve got you covered. Take our quiz to see how you may qualify for our more accessible egg freezing opportunities, including our Split program, through which you can freeze your eggs for free when you donate half to another family who can’t conceive. 

We’re wishing you the best of luck on your egg freezing journey! 

Egg freezing, also known as oocyte cryopreservation, is a process where a woman's eggs are retrieved, frozen, and stored for later use. This allows women to preserve their eggs at their current age, potentially increasing their chances of having a biological child in the future.

Egg freezing is becoming more and more common, with a 30% increase in egg-freezing cycles from 2021 to 2022 alone! 

I’m Dr. Meera Shah, a double-board certified OBGYN and Reproductive Endocrinologist (REI). I have helped countless women freeze their eggs as a fertility doctor and as a Medical Advisor to Cofertility. This article is a guide to everything you need to know to make a confident, informed decision about egg freezing.

Why people choose to freeze their eggs

There are many reasons why women opt for egg freezing. Here are some of the most common reasons we hear:

• Focusing on other priorities: Women focusing on career or personal goals can freeze their eggs until they're ready to start a family.
• Waiting for the right partner: As the average age of first marriage continues to rise, some women choose to freeze their eggs instead of rushing into a marriage.
• Medical reasons: Women facing medical conditions or treatments that could impact fertility, such as chemotherapy or radiation, can freeze their eggs before undergoing these treatments.
• Genetic predisposition: Women with a family history of early menopause may choose to freeze their eggs to ensure they have viable eggs for future use.
• Peace of mind: Some women simply want the peace of mind knowing they have a backup plan for their fertility.

At what age should you freeze your eggs?

There is no perfect age at which to freeze your eggs. However, the younger you can do it, the better. According to the American Society for Reproductive Medicine (ASRM), an optimal time to freeze your eggs is in your 20s and early 30s, while you have a higher ovarian reserve and eggs are healthier. 

A large 2020 study at a fertility clinic that specializes in this area looked at egg freezing cycles for over 1,200 people. It compared the average number of eggs people of different ages were able to freeze versus the “optimal” or goal number of eggs they should freeze. This goal number was based on how many eggs would give them a 70% live birth rate after doing 1 or 2 egg freezing cycles (this rate is calculated using some other numbers and it typically goes up as we age to make up for the lower number of healthy eggs). 

The study found that younger people, unsurprisingly, have an easier time freezing the goal number of eggs in one cycle. As people aged, they needed multiple egg freezing cycles to reach that goal number.

Read more in What’s the Best Age to Freeze My Eggs?

Is it worth freezing eggs after age 35?

The findings from the study above bring up a common question–is it worth freezing eggs after age 35? Well, it depends. The ASRM does not recommend egg freezing for people older than 38, but this isn’t a strict cutoff. 

Your biological clock is not a cliff. Everyone’s fertility decreases down at a different rate. Having your fertility hormones checked can sometimes help you and your doctor get a general idea of your ovarian reserve and chance of a future pregnancy. This can better help you decide if egg freezing is right for you.

Egg freezing success rates by age

Success rates with egg freezing depend on a lot of factors: your health, your ovarian reserve, your response to egg freezing medication, and the quality of the clinic. That being said, generally, younger women have higher success rates due to better egg quantity and quality. 

A study of 1,241 women found that the average number of eggs retrieved on the first egg freezing round was:

• 21 eggs for women under 35
• 17 eggs for women 35-37
• 14 eggs for women 38-40

‍

Because women in their 30s tend to produce less eggs, at this age you may end up having to either settle for fewer eggs for freezing or undergo multiple rounds to collect enough eggs to have on hand for later implantation. As you can imagine, those costs can creep higher and higher the more rounds you endure. 

Now, you might be thinking: isn’t 14 eggs a lot?  It’s true that eggs retrieved from women under the age of 36 will have a 95 percent survival rate after being thawed.  But, not all thawed eggs will become viable embryos and lead to a live birth. The probability of a live birth varies with the age of the woman trying to conceive and the number of mature eggs available. In short, the older the woman, the more eggs required to achieve a high probability of a live birth. 

A study in the Journal of Assisted Reproduction and Genetics further supports this point. For example, a woman under 35 will need nine eggs to achieve a 70% chance of having at least one live birth. If you’re trying to conceive in your mid to late 30s, you may need double as many eggs to achieve that same 70% success rate. 

The right number of eggs to freeze for your age

Different folks have different reasons for freezing their eggs. Some may be thinking about prolonging their fertility into the future. Others may be freezing some eggs but also hoping to donate some eggs to help others grow a family — something that’s done via our Split program, where you freeze for free when donating half of the eggs to a family that can’t otherwise conceive. 

Either way, studies have found that the optimal number of eggs to freeze really comes down to your age. That’s because the number of eggs in the body isn’t the only thing to decrease as you get older — egg quality decreases too, and egg quality is the number one factor in determining whether an egg can eventually result in a live birth. 

Here are the number of eggs you’ll want to freeze based on your age in order to obtain an optimal live birth rate:

Should I do multiple egg retrievals?

What happens if you don’t get as many eggs as you had hoped during your egg retrieval cycle? 

If you’ve undergone one round of egg freezing and the number of eggs your reproductive endocrinologist retrieved from your ovaries wasn’t as high as you’d hoped, you may want to talk to them about trying again. A fertility specialist can help you talk through all of your options.

There is technically no limit to the number of egg freezing rounds a person can undergo, but it’s not recommended that egg donors undergo more than six cycles. If you’re hoping to split your eggs with intended parents (donating half of the eggs retrieved) as part of our Split Program, you may find that additional retrievals help you provide the optimal amount of eggs for a live birth for you and for the intentend parents too. 

The right number of eggs to freeze to have multiple children

If you’re planning to have a big family one day, you may want to look at the number of eggs it’s recommended you freeze to achieve one live birth and talk to your Reproductive Endocrinologist (REI) about freezing more eggs. 

As we shared above, a woman under age 35 will need to freeze about nine eggs to achieve a 70% chance of a successful pregnancy and live birth. If you’re under age 35 now and thinking you might want to use frozen eggs to conceive twice in your future, you will want to freeze closer to 18 eggs.

The number of eggs necessary will increase with your age at time of the retrieval, and the number of children you hope to have via those eggs. 

Can frozen eggs guarantee a successful pregnancy in the future?

When trying to decide if you should freeze your eggs, it’s important to know that egg freezing is not an “insurance policy” for your fertility. While egg freezing can take some of the stress of having a baby right now off your shoulders, it is not a guarantee that you’ll have a baby in the future. 

Why not? Well, for one, not all the eggs that get frozen will actually be viable. It’s expected that some eggs will not survive the warming process when it comes time to use the eggs. In addition, the chances of the eggs that do survive being successfully fertilized depends on a variety of factors, including how old you were when you froze them (more on this later). 

This is not to sway your decision one way or another. Ultimately, only you and your doctor can decide if egg freezing is the right decision for you. But it's important to go in knowing that it’s not meant to be a done deal. As egg freezing has gotten more popular, many companies will gloss over this fact. We don't think that's right and want to be straight with you from the outset.

Freezing your eggs when you’re unsure if you want kids

Perhaps the biggest benefit of egg freezing is that it puts the decision-making power entirely in your hands. Whether you’re freezing your eggs because you want to focus on your career or you’re about to undergo medical treatment that may affect your fertility later on, or you’re waiting to find the right partner, freezing your eggs allows you to preserve some of your fertility independently. 

While you might not be sure about having kids today, if you do decide you want kids down the road, especially if you’re in your mid- to late-thirties, having eggs on ice will increase the chances that you’re able to do so.

Know this: most people do not regret their egg retrieval procedure. We looked at five studies on egg freezing. The rates of regret reported in these studies varied, likely due to the sample size, study design, and the follow-up period. However, taken together, these studies suggest that the vast majority of those who freeze their eggs have zero regrets.

There also appear to be factors that reduce the chances of regret, including feeling fully informed beforehand, and getting adequate support during the egg freezing process. In other words, if you take the time to think things through and feel supported throughout the journey, you’re less likely to regret making this decision for yourself.

The egg freezing process: step-by-step

The egg freezing process is about a two-week journey. You will work closely with a Reproductive Endocrinologist (fertility doctor) and the clinic team throughout the process. 

Here's a detailed breakdown of what you can expect from start to finish, and beyond:

1. Ovarian stimulation: You'll take hormone medications to stimulate your ovaries to produce multiple eggs, and have multiple monitoring appointments and blood tests to see how the eggs are maturing.
2. Egg retrieval: Your eggs will be retrieved through a minor surgical procedure using ultrasound guidance.
3. Vitrification: Your eggs will be rapidly frozen using a technique called vitrification, which helps preserve their quality.
4. Storage: Your frozen eggs will be stored in a secure facility until you're ready to use them.
5. Thawing and fertilization: When you're ready to conceive, your eggs will be thawed, fertilized with sperm (either your partner's or a donor's), and transferred to your uterus.

Will egg freezing hurt my future fertility?

Egg freezing actually rescues all the other eggs that your body would otherwise allow to die during a normal menstrual cycle. So the process of egg freezing doesn’t take anything away from your egg reserve, it actually helps you save some extra eggs! And since during each cycle, your body goes through the ovulation process again with a new set of competing eggs, your chances of getting pregnant unassisted in the future also aren’t affected by egg freezing. 

What egg freezing does do is give you additional options for if and when you’re ready to start growing your family.

Is egg freezing safe?

Like any other procedure, there are risks and side effects when freezing eggs, including risks of anesthesia, bleeding, pain, and infection. Thankfully, the majority of people who go through with it deal with side effects for a few days at most. When it comes to the ovaries themselves, they generally recover quickly. The overall data indicate that the potential risks of surgical complications from egg retrieval are generally very small. However, in people with a history of endometriosis, pelvic inflammatory disease, pelvic adhesions or previous pelvic surgery, the risks are slightly increased so make sure to speak to your doctor about your medical history if you fall into any of these categories.

Egg freezing vs embryo freezing 

There’s one major difference between freezing eggs and freezing embryos. When you freeze your eggs, they stay unfertilized. We all know that to make a baby, you need an egg and a sperm because each of them provides half of the material needed. On its own, an egg can’t function (and neither can a sperm).

An embryo, on the other hand, is an egg that has already been fertilized by a sperm. Once they combine, the egg and sperm become a single cell. Over the next three to four days, the embryo divides several times, going from one to two to four to eight cells, and so on until it reaches the blastocyst stage and is ready to be frozen. Once an embryo has developed, there’s no going back– that is, there’s no way to turn that embryo back into a separate egg and sperm. 

If you don’t know who you want to have children with, then freezing your eggs may be the best approach. This option gives you the freedom to hold off on thinking about having a baby until you’ve met someone or are ready to choose a sperm donor. 

On the other hand, if you are currently with a partner who you know you’d like to have children with but now isn’t the right time, then frozen embryos might be the way to go with the goal of a future embryo transfer. The caveat here is to be 100% certain—stars like Sofia Vergara and more recently, Anna Kendrick, have run into trouble after freezing embryos with partners they didn’t end up with. 

Read more in Should I Freeze Eggs or Embryos?

Cost of egg freezing

The question of how much does it cost to freeze your eggs will come down to a few factors. These include the number of cycles you undergo to retrieve eggs and how long you keep the eggs in storage. Overall, the typical egg freezing can cost anywhere from $10,000 to $20,000 for one cycle plus the cost of storage fees.

Another option? Freeze by Co offers women a chance to freeze their eggs for free when they donate half of the retrieved eggs to a family that can’t otherwise conceive. The cost of the entire process, including 10 years of cryopreservation, is fully covered — we think it’s a win-win. 

Or, if you want to freeze and store your eggs for your own future use without donating, Freeze by Co offers lower prices on things like consultations and storage, along with access to our community of freezers. ‍We partner with lenders, like Sunfish, to offer you fertility financial resources.

Learn more about egg sharing

Egg sharing programs exist worldwide to help make fertility care more accessible. Egg sharing is when a woman undergoes an egg retrieval, and some of the resulting eggs are donated to a family that can’t otherwise conceive.

In Cofertility’s Split program, women can freeze their eggs for free when they donate half of the retrieved eggs to a family who can’t otherwise conceive. 

Ask us anything

If you’d like help figuring out when to freeze your eggs, you can contact us for more information. While every woman’s fertility preservation path differs, we can connect you with reputable clinics who can offer basic guidance about when the time is right for you to freeze your eggs during a consultation or dig into specifics by going through a preliminary exam in a provider’s office.

We understand that the timing may not be right for you to start a family right now, but that doesn’t mean it’s too early to start thinking about what choices will be available to you when that time comes. As you can see, a lot goes into preparing for an egg retrieval process.  The earlier you consider your fertility, the more options you’ll have. 

Whether you decide to freeze or not, we’re here for you to answer any questions or talk through any concerns.