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

Causes, incidence, and risk factors

Normally, a woman produces one egg per month. Some women who have trouble getting pregnant may be given medicines to help them make more 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 ovarian hyperstimulation syndrome (OHSS). OHSS occurs only after the eggs are released from the ovary (ovulation).

You may be more likely to get OHSS if:

• Your doctor gives you 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 up to 1 in 10 women who go through in vitro fertilization.

Other risk factors for OHSS include:

• Age younger than 35
• Very high estrogen level during fertility treatments
• Polycystic ovarian syndrome

Symptoms

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:

• Significant weight gain (more than 10 pounds in 3 - 5 days)
• Severe pain or swelling in the belly area
• Decreased urination
• Shortness of breath

Signs and tests

If you have a severe case of OHSS, your health care provider will need to carefully monitor your symptoms. You may be admitted to the hospital.

Your weight and size of your belly area (abdomen) will be measured. Tests that may be done include:

• Abdominal ultrasound or vaginal ultrasound
• Chest x-ray
• Complete blood count
• Electrolytes panel
• Liver function test
• Tests to measure urine output

Treatment

Mild cases of OHSS usually don't need to be treated. You can ease your discomfort by doing the following:

• 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 - 12 glasses 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, which 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 (5 or more pounds a day).

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

Expectations (prognosis)

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.

Complications

In rare cases, OHSS can lead to life-threatening complications, including:

• Blood clots
• Kidney failure
• Severe electrolyte imbalance
• Severe fluid build-up in the abdomen or chest

Calling your health care provider

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

• Decreased urination
• Dizziness
• Excessive weight gain (more than 5 pounds a day)
• Nausea so intense that you can't keep food or liquids down
• Severe abdominal pain
• Shortness of breath

Prevention

If you are receiving injections of fertility medicines, your doctor will monitor you carefully with blood tests and pelvic ultrasounds to make sure that your ovaries aren't over-responding.

If your estrogen level rises very high or very quickly while taking fertility injections, your risk for OHSS is increased. You may need to take a lower dose of the medicines or temporarily stop treatment.

Some women may be given a protein solution called albumin to reduce the chances of OHSS.

References

1. Lobo RA. Infertility: etiology, diagnostic evaluation, management, prognosis. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2007:chap 41.
2. Schorge JO, Schaffer JI, Halvorson LM, et al. Treatment of the infertile couple. In: Cunningham FG, Leveno KL, Bloom SL, et al, eds. Williams Obstetrics. 23rd ed. New York, NY: McGraw-Hill; 2010:chap 20.

Review Date: 7/19/2012.

Reviewed by: Shehzad Topiwala, MD, Chief Consultant Endocrinologist, Premier Medical Associates, The Villages, FL. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.