During the course of your treatment cycle, you will have had a course of daily injections (e.g. gonal F) to stimulate the development of ovarian follicles and eggs. These injections are synthetic human pituitary hormones and are designed to increase the number of follicles and therefore the number of eggs available for your treatment.

Despite our best efforts to select the appropriate dosage to match your personal characteristics, an occasional patient may show excessive sensitivity, even to tiny doses of the hormones. This results in Ovarian Hyperstimulation Syndrome (OHSS).

During OHSS, the ovaries may become very large once the eggs have been collected, and fluid accumulates in the pelvis and abdominal cavity. The symptoms include abdominal discomfort and swelling, and sometimes nausea and vomiting. It usually starts a few days after the eggs have been collected, and lasts for a few days before everything returns to normal.

Ultrasound scanning helps greatly in recognizing the problem, and if the risk of OHSS is predicted before the egg collection, we may discuss stopping the treatment cycle to prevent its occurrence.

In the majority of cases, no special treatment is required other than increasing the intake of fluids by mouth to prevent dehydration. In about 3% of patients, it may be more severe and hospitalization may be required. During admission, intravenous fluids will be given and fluid from the abdomen may be tapped to relieve pressure. Although the condition is unpleasant, it is self-limiting and the patient recovers completely with no long-term effects.

OHSS does not reduce your chance of getting pregnant. In fact, studies confirm that patients who develop it are more likely to get pregnant.