Ovarian Hyperstimulation Syndrome (OHSS)

Women having IVF treatment, or considering having it, should be made aware of the risks of a complication, or syndrome, that could arise whilst on this type of fertility treatment. Those women having IVF treatment have a higher percentage of risk of it than those on fertility drugs, as a consequence of induction.

However, women on fertility drugs to stimulate ovarian production are at risk too from this potentially serious complication as a result of the type of assisted conception technique they receive. Sometimes, when overstimulated ovaries enlarge, chemicals released make blood vessels leak fluid, this causes Ovarian Hyperstimulation Syndrome to occur and as many as 1 in 3 women, or 33%, will suffer from this complication in its mild form, and 1 in 20 women could develop it moderately or seriously.

The chemicals released into the bloodstream by enlarged ovaries cause tiny blood vessels to leak fluid into the abdomen, and in severe cases, into the space surrounding the heart and lungs. The kidneys, liver and lungs can all be affected. Rarely, thrombosis can occur, and there have been reports of a small number of deaths from this complication.

The mild symptoms that are associated with Ovarian Hyperstimulation Syndrome are bloating of the abdomen, mild pain in the abdomen, and an ovarian size of 8cm. In moderate cases, the symptoms of abdominal pain will be accompanied by vomiting, ultrasound evidence of the accumulation of serious fluid in the peritoneal cavity will be presented, and the ovarian size will be 8-12 cm.

Severe cases will present with an ovarian size of 12 cm, could have all of the above symptoms, and may also be suffering from an abnormally small production of urine, low levels of protein in the blood, and a measurement or hematocrit reading of 45%.

Ovarian hyperstimulation syndrome presented in a critical state may also show acute respiratory distress syndrome as well as above symptoms. Mild symptoms can resolve in a few days or a few weeks if pregnancy occurs. However, any woman who is on IVF treatment who suffers any of the above, pregnant or not, should call for medical help.