Infertility In Women - Medications

GnRH Analogs (Agonists or Antagonists). Gonadotropin-releasing hormone analogs (GnRH-a) can be either GnRH agonists or antagonists. They are synthetic agents that are similar to natural GnRH but have very different actions. While natural GnRH stimulate a surge in LH, these agents actually prevent the LH surge that occurs right before ovulation. This action helps prevent the premature release of the eggs before they can be harvested for assisted reproductive technologies.

GnRH agonists include leuprolide (Lupron), nafarelin (Synarel), goserelin (Zoladex), and buserelin.
GnRH antagonists include ganirelix (Antagon) and cetrorelix (Cetrotide). These are newer agents that are proving to simplify the procedure because of their quicker action compared to GnRH agonist. They appear to pose less of a risk for complications and side effects in the treatment process. It is not clear, however, if they offer any advantages in achieving pregnancies.

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GnRH-a agents are administered by injection or nasal spray. They increase the risk for ovarian cysts, but according to a 2000 study, they have no negative effect on pregnancy. These agents cause menopause-like effects, including hot flashes, vaginal dryness, insomnia, and possible osteoporosis (bone loss). Depression may be significant.

Complications of Superovulation

Multiple Births. Overproduction of follicles can lead to ovarian enlargement. This event increases the risk for multiple births. There is a 25% chance of multiple births (about 17% for twins and 8% for triplets and over).

Ovarian Hyperstimulation Syndrome. The most serious complication with superovulation is ovarian hyperstimulation syndrome (OHS), which is associated with the enlarged ovary (although the precise cause is unknown). This can result in dangerous fluid and electrolyte imbalances and endanger the liver and kidney. OHS is also associated with a higher risk for blood clots. In rare cases, it can be fatal. Symptoms include abdominal bloating, nausea, vomiting, and shortness of breath.

Bleeding and Rupture of Ovarian Cysts. Overproduction of follicles, if unchecked, may result in bleeding and rupture of ovarian cysts.

Cancer Concerns. There has been concern about an increased risk for ovarian and breast cancers in women taking fertility drugs, particularly clomiphene and human menopausal gonadotropins. In general, a strong body of evidence is finding no higher risk for either breast or ovarian cancer from the drugs themselves. Instead, such studies are suggesting that these cancers are caused by the same factors that contribute to the infertility itself. One exception, according to a 2003 study, may be a higher risk for breast cancer in women who took hMG for six or more months or cycles. The number of subjects was small, however, and more research is needed to confirm this finding.