GnRH agonists and endometriosis-associated infertility

A retrospective analysis of pregnancy outcomes suggests that a GnRH-agonist rather than a GnRH-antagonist protocol may be beneficial in women with endometriosis-related infertility. The findings, published in the Journal of Gynecology, Obstetrics and Human Reproduction, were reported by French investigators.

For the study, the researchers compared pregnancy outcomes in women with endometriosis-associated infertility after controlled ovarian hyperstimulation with a long agonist protocol or a 6-week oral contraception-antagonist protocol. The data, recorded from January 2013 to October 2015, were from 165 cycles with a GnRH agonist protocol and 119 with a GnRH-antagonist protocol in 218 women with endometriosis.

Per started cycle, pregnancy and live-birth rates after fresh embryo transfer were higher in the women who received GnRH agonists than those who received GnRH antagonists (25% vs 13%, P = 0.02 and 18% vs 8%, P = 0.04, respectively).  Analysis per cycle with embryo transfer showed similar pregnancy rates for GnRH agonists and GnRH antagonists but a higher live-birth rate in the women who received GnRH agonists (29% vs. 17%, P = 0.053 and 22% vs 10%, P = 0.02, respectively). With freeze-thaw embryo transfer, no differences were observed between the two groups. Subgroup analysis for endometrioma alone, deep infiltrating endometriosis with and without endometrioma, and endometriosis with and without adenomyosis also showed no differences between the groups for either pregnancy or live-birth rates.

A GnRH-agonist protocol, the authors concluded, may result in higher pregnancy and live-birth rates after fresh embryo transfer in women with endometriosis-related infertility, suggesting that endometrial receptivity may be negatively affected by a GnRH-antagonist protocol.