Learn About Ovarian Hyperstimulation Syndrome

What is the definition of Ovarian Hyperstimulation Syndrome?

Ovarian hyperstimulation syndrome (OHSS) is a problem that is sometimes seen in women who take fertility medicines that stimulate egg production.

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What are the alternative names for Ovarian Hyperstimulation Syndrome?


What are the causes of Ovarian Hyperstimulation Syndrome?

Normally, a woman produces one egg per month. Some women who have trouble getting pregnant may be given medicines to help them produce and release eggs.

If these medicines stimulate the ovaries too much, the ovaries can become very swollen. Fluid can leak into the belly and chest area. This is called OHSS. This occurs only after the eggs are released from the ovary (ovulation).

You may be more likely to get OHSS if:

  • You receive a shot of human chorionic gonadotropin (hCG).
  • You get more than one dose of hCG after ovulation.
  • You become pregnant during this cycle.

OHSS rarely occurs in women who only take fertility drugs by mouth.

OHSS affects 3% to 6% of women who go through in vitro fertilization (IVF).

Other risk factors for OHSS include:

  • Being younger than age 35
  • Having a very high estrogen level during fertility treatments
  • Having polycystic ovarian syndrome
What are the symptoms of Ovarian Hyperstimulation Syndrome?

The symptoms of OHSS can range from mild to severe. Most women with the condition have mild symptoms such as:

  • Abdominal bloating
  • Mild pain in the abdomen
  • Weight gain

In rare cases, women can have more serious symptoms, including:

  • Rapid weight gain (more than 10 pounds or 4.5 kilograms in 3 to 5 days)
  • Severe pain or swelling in the belly area
  • Decreased urination
  • Shortness of breath
  • Nausea, vomiting, or diarrhea
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What are the current treatments for Ovarian Hyperstimulation Syndrome?

Mild cases of OHSS usually don't need to be treated. The condition may actually improve the chances of becoming pregnant.

The following steps can help you ease your discomfort:

  • Get plenty of rest with your legs raised. This helps your body release the fluid. However, light activity every now and then is better than complete bed rest, unless your doctor tells you otherwise.
  • Drink at least 10 to 12 glasses (about 1.5 to 2 liters) of fluid a day (especially drinks that contain electrolytes).
  • Avoid alcohol or caffeinated beverages (such as colas or coffee).
  • Avoid intense exercise and sexual intercourse. These activities can cause ovarian discomfort and may cause ovarian cysts to rupture or leak, or cause the ovaries to twist and cut off blood flow (ovarian torsion).
  • Take an over-the-counter pain reliever such as acetaminophen (Tylenol).

You should weigh yourself each day to make sure you are not putting on too much weight (2 or more pounds or about 1 kilogram or more a day).

If your provider diagnoses severe OHSS before transferring embryos in an IVF, they may decide to cancel the embryo transfer. The embryos are frozen and they wait OHSS to resolve before scheduling a frozen embryo transfer cycle.

In the rare case that you develop severe OHSS, you will probably need to go to a hospital. The provider will give you fluids through a vein (intravenous fluids). They will also remove fluids that have collected in your body, and monitor your condition.

Who are the top Ovarian Hyperstimulation Syndrome Local Doctors?
Highly rated in

Imperial College London

London, ENG, GB 

Ali Abbara is in London, United Kingdom. Abbara is rated as an Elite expert by MediFind in the treatment of Ovarian Hyperstimulation Syndrome. They are also highly rated in 8 other conditions, according to our data. Their top areas of expertise are Ovarian Hyperstimulation Syndrome, Hypogonadism, Infertility, and Amenorrhea.

Highly rated in

Imperial College London

London, ENG, GB 

Waljit Dhillo is in London, United Kingdom. Dhillo is rated as an Elite expert by MediFind in the treatment of Ovarian Hyperstimulation Syndrome. They are also highly rated in 11 other conditions, according to our data. Their top areas of expertise are Ovarian Hyperstimulation Syndrome, Hypogonadism, Infertility, and Amenorrhea.

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Highly rated in
Reproductive Medicine

Stanford, CA 

Michael Dahan is a Reproductive Medicine doctor in Stanford, California. Dr. Dahan is rated as an Elite doctor by MediFind in the treatment of Ovarian Hyperstimulation Syndrome. He is also highly rated in 8 other conditions, according to our data. His top areas of expertise are Ovarian Hyperstimulation Syndrome, Ovarian Cysts, Polycystic Ovary Syndrome, and Infertility. He is licensed to treat patients in California.

What is the outlook (prognosis) for Ovarian Hyperstimulation Syndrome?

Most mild cases of OHSS will go away on their own after menstruation starts. If you have a more severe case, it can take several days for symptoms to improve.

If you become pregnant during OHSS, the symptoms may get worse and can take weeks to go away.

What are the possible complications of Ovarian Hyperstimulation Syndrome?

In rare cases, OHSS can lead to fatal complications. These can include:

  • Blood clots
  • Kidney failure
  • Severe electrolyte imbalance
  • Severe fluid buildup in the abdomen or chest
When should I contact a medical professional for Ovarian Hyperstimulation Syndrome?

Call your provider if you experience any of the following symptoms:

  • Less urine output
  • Dizziness
  • Excessive weight gain, more than 2 pounds (1 kg) a day
  • Very bad nausea (you cannot keep food or liquids down)
  • Severe abdominal pain
  • Shortness of breath
How do I prevent Ovarian Hyperstimulation Syndrome?

If you are getting injections of fertility medicines, you will need to have regular blood tests and pelvic ultrasounds to make sure that your ovaries aren't over-responding.

What are the latest Ovarian Hyperstimulation Syndrome Clinical Trials?
Comparison of Ovarian Response in Oocyte Donors Triggered With GnRH Agonists Depending on the LH Level the Day After the Triggering
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Effects of E2 (Estradiol), P4 (Progesterone) and LH Levels on the Day of Transfer and Endometrial Cavity Thickness on Implantation Success in Patients With Frozen-thawed Embryo Transfer Cycle: Prospective Data Analysis
What are the Latest Advances for Ovarian Hyperstimulation Syndrome?
Progestin-Primed Ovarian Stimulation Protocol for Patients in Assisted Reproductive Technology: A Meta-Analysis of Randomized Controlled Trials.
Prednisone combined with letrozole reduced risk of ovarian hyperstimulation syndrome (OHSS) in women undergoing long-term gonadotropin-releasing hormone analog treatment.
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Fertility preservation in breast cancer with oral progestin: is it an option? A pilot study.
What are our references for Ovarian Hyperstimulation Syndrome?

Catherino WH. Reproductive endocrinology and infertility. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier Saunders; 2020:chap 223.

Fauser BCJM. Medical approaches to ovarian stimulation for infertility. In: Strauss JF, Barbieri RL, eds.Yen & Jaffe's Reproductive Endocrinology. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 30.

Lobo RA. Infertility: etiology, diagnostic evaluation, management, prognosis. In: Lobo RA, Gershenson DM, Lentz GM, Valea FA, eds. Comprehensive Gynecology. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 42.