Women contemplating ovarian stimulation should be aware that the procedure carries risks that are comparable with the risks of elective surgery.

All women undergoing ovarian stimulation, such as during an IVF treatment cycle, experience enlargement of their ovaries and a complex change in their hormone balance. The condition is often marked by weight gain, as excess fluid is retained. For this reason it is important to note your weight at the beginning of each IVF cycle.
For up to 5% of stimulated women this can be quite unpleasant with abdominal bloating and pelvic discomfort, however, for <1% of stimulated women, the abdominal pain and fluid retention is so severe that admission to hospital is necessary. Symptoms may include marked abdominal swelling, nausea, vomiting and diarrhoea, lower abdominal pain, and shortness of breath.  Hyperstimulation varies in severity and rarely requires treatment in hospital, but you must contact the clinic if you notice any of the above symptoms so that we can monitor you closely.

"Ovarian Hyperstimulation Syndrome" (OHSS), usually presents a few days after embryo transfer; symptoms being provoked by the hCG injection (Pregnyl/Profasi).

Severe symptoms require:

- bed rest
- correcting the fluid imbalances with an intravenous drip
- relieving pain and nausea
- Injections of heparin to counter the tendency of the blood to clot abnormally.

Fortunately this condition is self-limiting. It usually resolves after several days, with a natural excretion of the abnormal accumulation of fluid, however it may persist for weeks, especially if a pregnancy has been achieved. Once the condition has resolved the pregnancy can be expected to proceed normally.

On RARE occasions very serious complications have been associated with OHSS:

1. Abnormal blood clotting has caused strokes
2. Blood clots have migrated to the lungs, a complication that can be fatal
3. Enlarged ovaries can twist or bruise, requiring surgery
4. Weeping of fluid into the abdomen may be accompanied by a similar collection of fluid about the lungs and heart, interfering with their proper function
5. Liver or kidneys may stop working effectively.

There have been individual case reports of blood clotting and stroke complications of severe OHSS. One and a half million IVF babies have been born world wide with only four deaths that have been reported in world medical literature.