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OHSS, or Ovarian Hyperstimulation Syndrome, is a rare but potentially serious complication of egg freezing and egg donation. OHSS occurs when the ovaries become swollen and painful as a result of the hormonal medications used to stimulate egg production during fertility treatment. If you are considering egg freezing or donation, you may be wondering if you are at risk for OHSS. In this article, we will discuss everything you need to know.

What is OHSS?

OHSS is a condition that can occur as a result of fertility treatment, particularly after egg freezing. During this treatment, patients receive hormonal medications to stimulate the ovaries to produce multiple eggs for retrieval. In some cases, the ovaries may become overstimulated and produce too many eggs, causing them to become swollen and painful.

OHSS is a rare complication of egg freezing, but it can be serious if left untreated. In some cases, OHSS can lead to hospitalization and require medical intervention. Severe OHSS can cause complications such as blood clots, kidney failure, and fluid buildup in the lungs.

Ultrasound image of severe OHSS (Source)

How common is OHSS?

Data suggest the incidence of mild OHSS is 20%–33%, moderate OHSS is 3%–6%, and severe OHSS occurs in 0.1%–2% of cycles. In rare cases, OHSS can be life-threatening, so it's important to be aware of the potential risks and to inform your doctor of any symptoms (severe abdominal pain, bloating, and nausea). 

The incidence of OHSS has decreased over the years due to a better understanding of the risk factors and evidence-backed data on how to prevent OHSS. 

How do you know if you are at risk for OHSS?

The risk of developing OHSS depends on several factors, including: 

  • Previous history of OHSS in past cycles
  • High number of follicles during treatment puts you at an increased risk of developing OHSS
  • Medications: The dosage and duration of hormonal medications can impact the chances of developing OHSS
  • Age: Patients under the age of 30 are at a higher risk of developing OHSS 
  • Low body weight puts you at a higher risk of developing OHSS
  • Polycystic ovary syndrome (PCOS) increases your risk of developing OHSS due to the increased sensitivity to fertility medications
  • Elevated hormone levels, including elevated serum estradiol (E2) concentrations and increased anti-Mullerian hormone (AMH) levels are risk factors for OHSS

Ask your doctor if they think you might be at higher-than-average risk for OHSS. If you are at high risk of OHSS, they may choose a specific protocol which utilizes the leuprolide trigger instead of hCG, which can prevent OHSS. Another medicine called cabergoline also can help reduce the fluid accumulation, or they may give you extra IV fluids at the time of egg retrieval. Most clinics will do extra monitoring of patients at risk of OHSS to decrease the risk of complications.

How many follicles put you at risk of OHSS?

Follicles are small sacs in the ovaries that contain eggs. During fertility treatment, patients are given medications to stimulate the ovaries to produce multiple follicles, which can increase the chances of achieving pregnancy down the line. However, when too many follicles develop, the risk of OHSS increases.

Ultrasound scans and blood tests are used to monitor the number and size of follicles, as well as hormone levels. There is no set number of follicles that puts you at risk of developing OHSS, as the risk varies depending on other factors such as age, body weight, and response to medications. However, as a general guideline, having more than 20 follicles on an ultrasound scan is considered a high risk for OHSS. If you are deemed to be at high risk of developing OHSS, your doctor may adjust your medication dosages or cancel the cycle to prevent OHSS from developing.

There is no set number of follicles that puts you at risk of developing OHSS. However, as a general guideline, having more than 20 follicles on an ultrasound scan is considered a high risk for OHSS.

Symptoms of OHSS after egg retrieval

Most people who undergo egg freezing do not develop OHSS. For those who do, the severity of the symptoms can vary from mild to severe and may include:

  • Abdominal pain or discomfort: Patients with OHSS may experience abdominal pain or discomfort, which can range from mild to severe. This pain may feel like bloating, cramping, or a fullness in the abdomen.
  • Bloating and fluid retention: OHSS can cause fluid to accumulate in the abdomen, leading to bloating and a feeling of fullness. Patients with OHSS may also experience swelling in the hands and feet due to fluid retention.
  • Nausea and vomiting: Some patients with OHSS may experience nausea and vomiting, which can be caused by the swelling of the ovaries and the accumulation of fluid in the abdomen.
  • Difficulty breathing: In severe cases of OHSS, the accumulation of fluid in the abdomen can cause pressure on the diaphragm, making it difficult to breathe.
  • Rapid weight gain: People with OHSS may experience rapid weight gain due to the accumulation of fluid in the abdomen and other parts of the body.
  • Decreased urine output: OHSS can cause a decrease in urine output, which can be a sign of dehydration and electrolyte imbalances.
  • Fatigue: Patients with OHSS may experience fatigue, which can be caused by the body's response to the hormonal medications and the strain on the body's systems.

If you are undergoing egg freezing and experience any of these symptoms, it is important to contact your clinic immediately. Early recognition and management of OHSS can help to prevent the condition from worsening and ensure the best possible outcome.

How long after the egg retrieval are you at risk for OHSS?

The risk of OHSS typically peaks around five to ten days after egg retrieval. During this time, the hormones that were used to stimulate your ovaries to produce multiple eggs are still in your system, and your ovaries may continue to produce hormones even after the eggs have been retrieved. This can lead to excessive fluid accumulation and swelling in the body.

If you have undergone egg retrieval, it is important to be aware of the signs and symptoms listed above and report any concerns to your clinic right away.

Can you prevent OHSS after an egg retrieval?

Fertility doctors can identify your risk factors and take action to reduce your chances of getting OHSS in the first place. But there are also steps you can take to help prevent OHSS after egg retrieval. Here are some tips:

  • Stay hydrated: Drinking plenty of fluids, especially electrolyte-rich fluids like coconut water or gatorade, can help flush out excess hormones and prevent dehydration, which can contribute to the development of OHSS. Aim for at least eight to ten glasses per day, or as directed by your doctor.
  • Eat a high protein diet: A healthy, high protein diet is an important component of preparing for egg freezing.
  • Rest and avoid strenuous activity: After the egg retrieval, it is important to take it easy and avoid activities that could increase your risk of developing OHSS. This includes exercise, lifting heavy objects, and sexual activity. Your doctor will likely recommend that you rest for at least 24 to 48 hours after the procedure.
  • Monitor your symptoms: Be aware of the signs and symptoms of OHSS, such as those listed above. If you experience any of these symptoms, contact your clinic right away.
  • Take prescribed medications as directed: Your doctor may prescribe medications, such as pain relievers or hormone supplements, to help prevent OHSS after egg retrieval. It is important to take these medications as directed and not to skip any doses.
  • Attend follow-up appointments: Your doctor may schedule follow-up appointments to monitor your progress and check for signs of OHSS. Attend these appointments as scheduled and report any symptoms or concerns you may have.

While OHSS can be a serious complication, taking these steps can help reduce your risk and ensure the best possible outcome after egg retrieval. Be sure to discuss any concerns or questions you may have with your doctor, as they can provide personalized recommendations based on your individual needs and medical history.

How is OHSS treated?

Mild cases of OHSS can usually be treated with rest, increased fluid intake, and pain medication. More severe cases may require hospitalization and treatment with intravenous fluids, electrolyte replacement, and other supportive measures.

If you develop mild to moderate OHSS, your clinic may recommend close monitoring to ensure that your symptoms do not worsen. This may involve regular check-ins, blood tests, and ultrasounds to track your progress and check for signs of complications.

One of the most important treatments for OHSS is rest and hydration. This can help relieve symptoms such as bloating, abdominal pain, and nausea, and prevent complications such as dehydration and blood clots. Your doctor may recommend bed rest and increased fluid intake, and may also prescribe medications to manage your symptoms.

Your doctor may also prescribe medications such as pain relievers, anti-nausea medications, and diuretics (medications that help remove excess fluid from the body) to manage your symptoms and prevent complications. In some cases, medications such as cabergoline or GnRH agonists may be used to reduce the production of hormones that contribute to OHSS.

If you do develop severe OHSS, you may need to be hospitalized for close monitoring and treatment. In the hospital, you may receive intravenous fluids and medications, and may undergo procedures such as paracentesis (the removal of excess fluid from the abdomen) to relieve symptoms and prevent complications.

Does OHSS affect egg quality?

OHSS is caused by an overstimulation of the ovaries with fertility medications, which can lead to a higher number of eggs being produced than normal. However, the quality of those eggs is usually not affected by the presence of OHSS. In fact, one small study of 42 patients who developed severe OHSS during IVF found that while the fertilization rate was lower, the quality of embryos and the pregnancy rate were the same. 

The quality of the eggs retrieved during egg freezing is more dependent on your age and other factors, such as hormonal imbalances or underlying medical conditions. 

Does OHSS mean more eggs?

OHSS may mean more eggs, but only because having more eggs means a higher chance of OHSS. One of the main causes of OHSS is the use of medications called gonadotropins, which stimulate the ovaries to produce multiple eggs. Patients who produce a large number of eggs, usually more than 20, are at a higher risk of developing OHSS. 

In some cases, OHSS may indicate that a patient has produced a larger number of eggs than average. However, this is not always the case. Mild to moderate cases of OHSS can occur even when fewer than 10 eggs are retrieved.

Keep in mind that the number of eggs retrieved is not always an indicator of success. Other factors, such as the quality of the eggs, your age, and your overall health can all have an impact on the success of the treatment.

The goal of egg freezing is to produce a sufficient number of high-quality eggs for fertilization down the line, while minimizing the risk of complications such as OHSS. If you are undergoing egg freezing and have concerns about the number of eggs or the risk of developing OHSS, it is important to discuss your options with your doctor. They can provide guidance on the best course of action based on your individual circumstances and can help you make informed decisions about your fertility journey.

Summing it up

Egg freezing is becoming an increasingly popular option for those who want to preserve their fertility for future use. This process involves harvesting and freezing your eggs, which can then be thawed and used down the line when you are ready to start a family. However, like any medical procedure, egg freezing is not without its risks. One potential complication that can occur during the process of egg retrieval is OHSS.

While OHSS is a potential risk of egg freezing, the good news is that it is a relatively rare complication. Plus, the risk of OHSS can be reduced by carefully monitoring your response to the fertility medications and adjusting the dosage as needed. If you are worried about OHSS, we recommend talking to your doctor to discuss what can be done to reduce the risk.


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