Ovarian hyperstimulation Syndrome (OHSS)
Ovarian hyperstimulation syndrome (OHSS) causes swelling of the ovaries with leaking of fluid within the body. PCOS and the use of fertility treatments to stimulate the ovaries can increase the risk for OHSS. It affects about 10% of women who undergo traditional IVF. When it occurs, OHSS is usually temporary and resolves within 1-2 weeks. Mild symptoms include bloating, discomfort/pain, and weight gain. Severe cases of OHSS occur rarely and can lead to hospitalization due to serious symptoms and complications including severe pain, swelling in the abdomen, breathing problems, decreased urination, blood clots, and kidney failure.
Ultrasounds to check on the ovaries and blood tests to check on hormone levels are used to monitor for OHSS risk. To prevent or lessen the development of OHSS, your doctor may make changes to the dosing of your fertility drugs. This may mean delaying the use of a hormone treatment or not using it. In some cases, a drug called cabergoline may be recommended to prevent OHSS. Another strategy is to freeze embryos and delay embryo transfer in IVF until OHSS symptoms have resolved.
Sources: American Society for Reproductive Medicine,"Fact Sheet: Side-effect of injectable fertility drugs," revised 2012. Insler, V et al. "Prevention of ovarian hyperstimulation syndrome." UptoDate, reviewed February 2014.