Improving pregnancy outcomes in women with endometriosis: the role of GnRH analogs

This article reviewed current data regarding pregnancy outcomes in women with endometriosis treated with a gonadotropin-releasing hormone (GnRH) analog before in-vitro fertilization (IVF).

Endometriosis is a condition in which cells of the inner-most layer of the uterus can be found in other organs (most commonly the ovaries, bowel or tissue lining the pelvis). Endometriosis can cause severe pain, especially during periods or intercourse. Fertility problems may also develop.

Women with endometriosis are known to have lower successful pregnancy rates following IVF (the artificial matching of sperm and eggs in a laboratory dish). Several strategies have been attempted to increase success rates, such as surgery or treatment with certain drugs (GnRH analogs) for 3-6 months before IVF. GnRH analogs may promote “better” eggs and prepare the lining of the uterus to sustain the pregnancy. Notable drugs in this class include: triptorelin (Trelstar) and leuprolide (Lupron).

The present article analyzed data from 3 previously published studies with a pooled enrollment of 165 women. Pregnancy outcomes and complications were compared between women with endometriosis who had received GnRH analog treatment for 3-6 months before IVF and those who were directly referred to IVF.

GnRH analog treatment was associated with 4.3 times higher pregnancy rate (successful conception) in all three trials, and with significantly higher live birth rate (successful pregnancy resulting in live birth) in one trial (about 9 times higher). Having surgery to remove endometriosis was not found to influence IVF success rates.

GnRH analog treatment for 3 to 6 months before IVF increases the likelihood of a successful pregnancy in women with endometriosis. However, further studies with more participants are needed to confirm these results.

Because the study was performed using data from different trials with variable research methodology, few reliable conclusions could be drawn. Thus, it is not yet clear how GnRH analogs influence multiple pregnancy rates (having twins, triplets), and the rates of miscarriage, congenital abnormalities and other complications.