Ovarian Hyperstimulation Syndrome (OHSS)

Symptoms, Treatment, and Prevention

Young Woman Sitting On Bed Having Cramps from OHSS
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Being familiar with the symptoms of ovarian hyperstimulation syndrome (OHSS) is key to preventing a severe case. Ovarian hyperstimulation syndrome is typically mild, but it can become life-threatening. Catching the symptoms early, along with careful monitoring of your treatment cycle by your doctor, can lower the risk of serious complications.

OHSS is a potential side effect of fertility drugs, particularly with injectables (gonadotropins) taken during an IVF treatment cycle. Anywhere from 20% to 33% of women going through IVF treatment will experience ovarian hyperstimulation syndrome. However, most of these are mild cases—moderate cases occur in between 3% and 6% of IVF cycles and severe cases occur less than 1% of the time.

OHSS can occur while taking Clomid and other fertility drugs taken orally, but it's rare.


Some enlargement of the ovaries is normal during fertility drug treatment. With OHSS, though, the ovaries become dangerously enlarged with fluid. This fluid can leak into the belly and chest area, leading to complications. But the majority of the fluid doesn't come from the follicles themselves. Most of it comes from blood vessels that are "leaky" due to substances released from the ovary.


Ovarian hyperstimulation syndrome can only occur after ovulation has taken place. Symptoms may occur a few days after ovulation or IVF egg retrieval, or they may not show up for a week or more after ovulation.

Mild symptoms include:

  • Bloating
  • Diarrhea
  • Mild nausea
  • Mild pain or discomfort in the abdomen
  • Mild weight gain

More serious symptoms include:

  • Dizziness
  • Rapid heartbeat
  • Rapid weight gain, more than 10 pounds in 3 to 5 days.
  • Severe abdominal pain
  • Severe bloating
  • Severe nausea (so much that you can't keep down any food or fluids)
  • Shortness of breath
  • Trouble with urinating

If you experience mild symptoms, you should contact your doctor as soon as possible, so he or she can monitor the situation.

If you experience any of the serious symptoms, contact your doctor immediately.

Risk Factors

Some women are at a higher risk of developing OHSS than others. Your doctor should take these factors into account before your treatment cycle begins.

Your risk for OHSS may be higher if:

  • You have PCOS.
  • You're age 30 or younger.
  • Your AMH levels are high.
  • You've developed OHSS in the past.
  • You're thin or underweight.

Prescribing lower dosages of hormones, or using alternative treatment protocols, can reduce your risk. Your doctor may also more closely monitor your cycle. Even though OHSS can only occur after ovulation, there are signs your doctor can watch for that may indicate your risk is higher during a particular treatment cycle.

For example, if your ovaries develop "too many" follicles in response to the fertility drugs, or your levels of estradiol are rising rapidly, this may indicate your risk for OHSS this cycle is high.

Your doctor may cancel your treatment cycle if they suspect your risk is high. If you're having an IUI cycle, this may mean canceling the insemination and asking you not to have sexual intercourse. If you're having IVF, any fertilized embryos from the IVF treatment cycle can be frozen and saved for use during a future cycle.

One reason for canceling the treatment cycle is because if you get pregnant, recovery from OHSS may take longer. Pregnancy can worsen OHSS.

Another option your doctor can take is to delay ovulation by a few days. They may prescribe a GnRH antagonist, which will prevent the body's natural LH surge, preventing or delaying ovulation. Or, your doctor may simply delay administering the hCG trigger shot, a fertility drug that triggers ovulation.

Delaying ovulation to lessen the risk of ovarian hyperstimulation syndrome is sometimes referred to as "coasting." This delay of a few days can lower the risk and severity, without seriously decreasing your chances of a successful pregnancy.

Rare Complications

Having your treatment cycle canceled can be very disappointing. You may be tempted to have sexual intercourse against the instructions of your doctor, not wanting to "waste" the cycle. Don't do this.

OHSS can be dangerous and even life-threatening. If you develop a severe case of OHSS and get pregnant, your risk of miscarriage may also be higher.

Some of the possible complications of OHSS include:

  • Dangerous blood clots (usually in the leg)
  • Death (extremely rare)
  • Difficulty breathing
  • Fluid build-up in the lungs or abdomen
  • Kidney failure
  • Pregnancy loss
  • Ruptured ovarian cyst
  • Twisted ovary (the ovary gets so heavy with fluid, it twists on its own weight)

Prevention and Treatment

Your doctor should monitor your body's response to fertility drugs with blood tests and ultrasounds. Rapidly increasing estrogen levels or ultrasounds that show a large number of medium-sized follicles are all possible indicators of ovarian hyperstimulation syndrome risk.

If you develop a mild case of ovarian hyperstimulation syndrome, you probably won't need special treatment.

Here are some things you can do at home to feel better:

  • Don't drink alcohol or caffeinated drinks, such as coffee, colas or caffeinated energy drinks.
  • Don't overexert yourself; take it easy while you recover.
  • Drink plenty of fluids, around 10 to 12 glasses a day. Drinks with electrolytes, such as Gatorade, are a good choice.
  • Put your feet up. This can help your body get rid of the extra fluid.
  • Sex should be avoided until you feel better. Sexual activity may increase your discomfort, and in the worst-case scenarios, may cause ovarian cysts to leak or rupture.
  • Take over-the-counter pain relievers, such as Tylenol.
  • While you shouldn't overexert yourself, you should maintain some light activity. Total bed rest can increase the risk of some complications.

Your doctor will give you instructions on what to watch for and when to contact him. If your symptoms get worse, you should definitely let them know. She may ask you to weigh yourself daily, to monitor weight gain. If you find yourself gaining 2 or more pounds per day, you should call your doctor.

A Word From Verywell

In rare cases, you may need to be hospitalized. Hospitalization may include receiving fluids intravenously (through an IV), and they may remove some of the excess fluids in your belly via a needle. You may also be kept in the hospital for careful monitoring until your symptoms lessen. Usually, symptoms will decrease and go away once you get your period.

If you get pregnant, though, your symptoms may be prolonged. It may take several weeks to feel completely better. Pregnancy can also make the symptoms worse, so your doctor will want to monitor your situation carefully.

7 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Banker M, Garcia-Velasco JA. Revisiting ovarian hyper stimulation syndrome: Towards OHSS free clinicJ Hum Reprod Sci. 2015;8(1):13-17. doi:10.4103/0974-1208.153120

  3. American Society for Reproductive Medicine. Ovarian hyperstimulation syndrome.

  4. Practice Committee of the American Society for Reproductive Medicine. Electronic address: ASRM@asrm.org; Practice Committee of the American Society for Reproductive Medicine. Prevention and treatment of moderate and severe ovarian hyperstimulation syndrome: a guidelineFertil Steril. 2016;106(7):1634–1647. doi:10.1016/j.fertnstert.2016.08.048

  5. PCOS Awareness Association. Ovarian hyperstimulation syndrome (OHSS).

  6. Lane A. Ovarian hyperstimulation syndrome (OHSS) caused by fertility treatments. The Embryo Project Encyclopedia. Published October 20, 2020.

By Rachel Gurevich, RN
Rachel Gurevich is a fertility advocate, author, and recipient of The Hope Award for Achievement, from Resolve: The National Infertility Association. She is a professional member of the Association of Health Care Journalists and has been writing about women’s health since 2001. Rachel uses her own experiences with infertility to write compassionate, practical, and supportive articles.