Fertility medications work by stimulating the ovaries. The medications given via injection are most successful at stimulating the ovaries. For the most part, this is a good thing and the desired result of the treatment. However, the ovaries can sometimes become overstimulated. This is referred to as ovarian hyperstimulation syndrome.
Ovarian hyperstimulation syndrome occurs in about 5 percent of women using fertility medications. The symptoms can range from mild to severe. Between 1 and 2 percent of women experience severe symptoms.
The ovaries can become sensitive to the medications and increased estrogen level. This causes the ovaries to swell to several times their natural size. In some cases, they can grow to the size of an orange or even a grapefruit. This can cause other symptoms including abdominal pain, bloating, nausea and weight gain.
The good news is that in most cases the syndrome will naturally correct itself with the start of the next menstrual cycle. If you become pregnant, obviously you won’t get your period. Pregnancy increases the duration of the symptoms.
I can personally attest to this fact, since I developed ovarian hyperstimulation syndrome after undergoing IUI to conceive our first baby. The syndrome took over a month to resolve and I was put on bed rest for a total of six weeks. Thankfully, my daughter and I both made it through the ordeal, but it was not fun.
Currently, many doctors will halt treatment for the remainder of the cycle, if the ovaries are showing signs of hyperstimulation. There is mounting evidence that this is the best course of action.
A study at the Mayo Clinic analyzed the files of over 1,000 patients. Three different strategies were used with these patients, some skipped injections to reduce the levels, some had their eggs frozen for use at another cycle and the third group with no other risk factors for ovarian hyperstimulation continued with the embryo transfer.
The study found the best outcome was with the group that had their embryos frozen and the transfer delayed. This group had the lowest incidence of severe ovarian hyperstimulation syndrome and the highest live birth per patient ratio in the study.