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POI, POF, POR, DOR, FOR, TOR, Oh My! A Guide to Ovarian Reserve Acronyms
IVF

POI, POF, POR, DOR, FOR, TOR, Oh My! A Guide to Ovarian Reserve Acronyms

by
Halle Tecco, MPH, MBA
July 13, 2023
Last updated:
March 1, 2025
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Decoding the mysteries of infertility can sometimes feel like navigating a maze of medical jargon — POI, POF, POR, DOR, FOR… it can be enough to make your head spin. The journey is often filled with complex terminologies and a multitude of acronyms like these, making the process feel even more overwhelming than it already is. 

Each of these acronyms represents a distinct condition or factor that can influence fertility, and understanding them is vital to making informed decisions about your reproductive health.

These acronyms pertain to various ovarian conditions that can contribute to infertility, each with their unique challenges and treatment considerations. Though these conditions can introduce obstacles on the journey to parenthood, modern advancements in reproductive medicine provide promising solutions. In particular, egg donation stands as a beacon of hope for many individuals and couples navigating these challenges.

This article is designed to guide you through the intricacies of these terms, what they signify, their implications, prevalence, and treatment options. Whether you're just starting your journey or are already deep into exploring infertility treatments, understanding these terms can empower you to make informed decisions about your reproductive health.

POI - Premature Ovarian Insufficiency

What is POI

Premature Ovarian Insufficiency, or POI, is a condition where a woman's ovaries stop functioning normally before she reaches 40. This results in decreased fertility due to a lower production of eggs, irregular periods or even cessation of menstrual cycles. 

What causes POI

The causes can be varied, from genetic disorders to autoimmune diseases, and even certain treatments like chemotherapy. In cases of POI, the option of using donor eggs is a viable solution, as it bypasses the issue of egg production, providing a chance at successful conception.

Prevalence of POI

POI affects approximately 1% of the general population

How it's treated

‍There is no cure for POI, but there are several treatment options available. Hormone replacement therapy (HRT) can help alleviate symptoms of menopause and reduce the risk of osteoporosis and heart disease. Those with POI who wish to conceive can also explore fertility treatments like in vitro fertilization (IVF) with donor eggs. Not only can this option (of course) assist with egg quantity, but donor eggs also come from women who are likely to have higher quality eggs and produce healthy embryos.

POI - Primary Ovarian Insufficiency

Primary Ovarian Insufficiency means the same thing as Premature Ovarian Insufficiency: when the ovaries stop functioning normally before age 40. When talking about POI, “Primary Ovarian Insufficiency” is the preferred acronym over “Premature Ovarian Insufficiency” by the National Institutes of Health, because ovarian function is unpredictable in many cases. Also, since 5–10% of women with POI experience unassisted pregnancy, POI is different from menopause, when unassisted pregnancy is impossible. 

POF - Premature Ovarian Failure

Premature Ovarian Failure (POF), also often used interchangeably with POI, is a condition where the ovaries cease to function before the age of 40. In 2016, the New European Society of Human Reproduction and Embryology (ESHRE) proposed using the term “premature ovarian insufficiency” instead for research and clinical practice. 

POR - Poor Ovarian Response

What is POR

‍Poor Ovarian Response is a condition characterized by an inadequate response to ovarian stimulation during assisted reproductive procedures, such as In-Vitro Fertilization (IVF). Those with POR produce fewer eggs even when given fertility drugs designed to stimulate egg production. This condition reduces the chances of successful IVF due to the lower number of eggs available for retrieval and fertilization. 

Prevalence of POR

The estimated prevalence of POR ranges from 6% to 35%. This wide range is primarily due to researchers and clinicians having varying definitions of POR. 

How it's treated

Different strategies are employed to manage POR, such as using different protocols or higher doses of fertility drugs. There is some evidence that DHEA and CoQ10 may improve IVF pregnancy rates for those facing POR as well as some evidence that treatment with growth hormone (GH) for POR patients could lead to a higher number of retrieved eggs. In certain cases, fertility doctors may recommend alternative approaches such as the use of donor eggs or embryo adoption. These options can increase the chances of success by (ideally) giving you more healthy embryos to work with over a shorter period of time.

DOR - Diminished Ovarian Reserve

What is DOR

Diminished Ovarian Reserve refers to a decrease in the quantity of eggs. This condition is often related to aging, as the number of eggs declines naturally over time, but it can also occur prematurely in some. 

Prevalence of DOR

‍Between 10% to 30% of people who seek help for infertility have DOR.

How it's treated

Fertility treatments like IVF may be employed, but success rates can be lower due to fewer eggs. Depending on your family-building goals and timeline, the use of donor eggs from a younger, healthy donor can improve embryo fertilization outcomes by providing more eggs, in addition to significantly increasing the likelihood of pregnancy and reducing the risk of miscarriage.

FOR - Functional Ovarian Reserve

What is FOR

Functional Ovarian Reserve refers to the number of responsive follicles in the ovaries at a given time. It is frequently used synonymously with the term 'ovarian reserve'. Several research groups have used markers such as hormone levels or Antral Follicle Count (AFC) of follicles with diameters between 2-10 mm to measure FOR. Therefore, it seems that FOR is the term used to represent a biological quantification of the ovarian reserve. It is different from the diagnosis of Diminished Ovarian Reserve (DOR), which is based on a low Antral Follicle Count and/or hormonal indicators of reduced ovarian reserve.

Total Ovarian Reserve (TOR):

What is TOR

The Total Ovarian Reserve refers to the total number of immature eggs (primordial follicles) in the ovaries. This reserve is established at birth, decreases naturally with age, and can be influenced by certain medical conditions or treatments. 

Prevalence

A decline in TOR is a normal part of aging. However, some patients may experience a faster-than-normal decline due to conditions like POI or POF.

How it's treated

There is currently no proven method to increase the TOR since the number of eggs is established before birth. Fertility treatments aim to make the best use of the existing reserve and include ovulation induction, in-vitro fertilization (IVF), and in many cases, the use of donor eggs. Donor eggs provide a significant benefit for those with a low TOR, offering more eggs— and because they come from young, healthy donors, they increase the chance of a successful pregnancy.  

Find your match

What do these acronyms have in common? The “O.”

The unifying thread that weaves these acronyms together is the letter "O,” representing “Ovarian.” This commonality underlines the critical role the ovaries play in the reproductive system. Ovaries are responsible for egg production, crucial for the conception and reproduction process. Any disruption or disorder affecting the ovaries can have significant impacts on a woman's fertility.

Ovarian function

In conditions like POI and POF, the issue arises from an early cessation or significant decrease in ovarian function. The ovaries prematurely reduce their activity, leading to a limited supply or a complete lack of viable eggs.

Ovarian response

With POR, the ovaries do not respond adequately to fertility treatments designed to stimulate egg production. This poor response leads to fewer eggs being produced than expected, reducing the success rates of assisted reproductive techniques such as IVF.

Ovarian reserve

DOR, TOR, and FOR are all about the 'reserve' of eggs in the ovaries. They refer to the quantity of the eggs a woman has left. DOR is a decrease in the amount or quality of the eggs, TOR refers to the total number of immature eggs (primordial follicles) in the ovaries, and FOR refers to the number of responsive follicles or eggs that can potentially be fertilized.

These acronyms all point to various challenges related to the ovaries that can influence fertility. Understanding these terms allows for more informed discussions with healthcare professionals about potential treatment strategies.

What is the success rate of donor egg IVF?

Donor egg IVF has the highest success rate of any fertility treatment, and using donor eggs can drastically increase your chances of success. 

At every age, the chances of birth with donor eggs is better, but those who benefit the most from donor eggs are women over 35 and those with low ovarian reserve. In fact, about one-quarter of women over 40 who succeeded with IVF did so through the use of donor eggs. 

At Cofertility, for those who match with a donor in our fresh egg donation program, the average number of mature eggs a family receives and fertilizes is 12. The number of eggs retrieved varies by patient and cycle, but can be predicted by a donor’s age, AMH, and antral follicle count, all of which will be known to you after the donor’s initial screening. Qualified candidates have an ample ovarian reserve for both their own needs and sharing. Egg share donors also often work closely with a fertility doctor to determine, based on their own medical history, the optimal number of eggs needed for their own future family-building goals. Should it make sense for the donor, they may choose to pursue a second egg-sharing cycle to maximize the chances of success for everyone.

Matching with a donor in our frozen program can provide the opportunity to move forward with your family-building plans faster, as frozen eggs can be fertilized or shipped to your clinic immediately. Donors undergoing frozen cycles complete equally rigorous ovarian reserve testing. While the total number of frozen eggs available will vary based on the donor’s retrieval outcomes, every frozen match is guaranteed to have a minimum of at least 6 frozen eggs.

To learn more about these programs and the differences between them, click here.

The chart was made using the SART Patient Predictor for an average woman (5’4”, 150 lbs) with diminished ovarian reserve. As you can see, the chances of live birth after one donor egg cycle is 54% for recipients under 40, and only goes down slightly after this.

Find an amazing egg donor at Cofertility

At Cofertility, our program is unique. After meeting with hundreds of intended parents, egg donors, and donor-conceived people, we decided on an egg donation model that we think best serves everyone involved: egg sharing. 

Here’s how it works: our unique model empowers women to take control of their own reproductive health while giving you the gift of a lifetime. Our donors aren’t doing it for cash – they keep half the eggs retrieved for their own future use, and donate half to your family.

We aim to be the best egg sharing program, providing an experience that honors, respects, and uplifts everyone involved. Here’s what sets us apart:

  • Human-centered. We didn’t like the status quo in egg donation. So we’re doing things differently, starting with our human-centered matching platform.
  • Donor empowerment. Our model empowers donors to preserve their own fertility, while lifting you up on your own journey. It’s a win-win.
  • Diversity: We’re proud about the fact that the donors on our platform are as diverse as the intended parents seeking to match with them. We work with intended parents to understand their own cultural values — including regional nuances — in hopes of finding them the perfect match.
  • Baby guarantee. We truly want to help you bring your baby home, and we will re-match you for free until that happens.
  • Lifetime support: Historically, other egg donation options have treated egg donor matching as a one-and-done experience. Beyond matching, beyond a pregnancy, beyond a birth…we believe in supporting the donor-conceived family for life. Our resources and education provide intended parents with the guidance they need to raise happy, healthy kids and celebrate their origin stories.

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. Create a free account to get started today!

Halle Tecco, MPH, MBA

Halle Tecco is the Chair and co-founder of Cofertility and is a healthcare founder investor, and women's health advocate. She previously founded Rock Health and then Natalist (acquired by Everly Health). She is a Board Director at Resolve and an Adjunct Professor at Columbia Business School. Halle received her MBA from Harvard Business School and her MPH from Johns Hopkins University with a concentration in Women’s and Reproductive Health.

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