What causes ovarian hyperstimulation syndrome (OHSS)?

In most cases, OHSS develops because of high levels of the pregnancy hormone hCG following fertility treatments that stimulate the production of many eggs at one time, as is done with many IVF protocols. In very rare cases, patients have genetic mutations in certain hormone receptors that predispose them to developing OHSS even without hormonal treatments.

In women with OHSS, drugs used in fertility treatments cause the blood vessels surrounding the ovaries to leak fluid. This fluid causes the ovaries to swell. Sometimes this fluid moves into the belly and other areas, causing:

• Swelling.
• Pain.
• Nausea.
• Vomiting.
• Increased thirst.

In severe forms, the excess fluid can result in difficulty breathing and decreased urination.

What are the symptoms of ovarian hyper stimulation syndrome (OHSS)?

The signs and symptoms of OHSS vary depending on the severity of the condition. Symptoms of mild to moderate OHSS include:

• Abdominal pain.
• Bloating.
• Sleight weight gain.
• Nausea.

In more severe cases of OHSS, symptoms may include:

• Excessive weight gain.
• Severe nausea and vomiting.
• Severe abdominal swelling.
• Difficulty breathing.
• Blood clots.
• Decreased urination.
• Kidney failure.
• Severe abdominal pain.