GnRH agonist vs. hCG: which is more effective to trigger ovulation in women with a history of follicular-endometrial asynchrony?

This study investigated the effects of GnRH agonist to stimulate ovulation in women with a history of follicular-endometrial asynchrony. They found that GnRH agonist was associated with higher rates of clinical pregnancy and live birth compared to standard hCG treatment. 

One approach for treating unexplained infertility is intrauterine insemination (IUI). This involves delivering sperm into the uterus following treatment with clomiphene citrate, a medication that stimulates the ovary to produce an egg. A woman will also receive treatment to stimulate ovulation (egg release). Human chorionic gonadotrophin (hCG) is a hormone that is typically prescribed to trigger ovulation.

GnRH agonist (GnRH-a) is an alternative medication to stimulate ovulation. GnRH-a causes the body to increase the production of hormones including lutenizing hormone (LH). Some studies suggest that hCG treatment leads to low LH and may prevent the endometrium (womb lining) from growing properly. If this happens, the fertilized egg or follicle may rupture (lutenized unruptured follicle, LUF) and the pregnancy can be lost. This condition is called follicular-endometrial asynchrony.

It is unclear if GnRH-a is more effective than hCG in patients with follicular-endometrial asynchrony undergoing fertility treatment. 

This study investigated whether GnRH-a is more effective than hCG in patients with folliucular-endometrial asynchrony.

This study included 513 female patients with a history of follicular-endometrial asynchrony seeking fertility treatment. Patients were assigned to undergo GnRH-a or hCG treatment to stimulate ovulation. Once ovulation was confirmed (up to 72 hours later) patients underwent IUI.

Patients in the GnRH-a group had higher rates of clinical pregnancy and live birth compared to hCG patients. There were no cases of ovarian hyperstimulation syndrome in either group. Miscarriage rates were similar in both groups. There was a higher incidence of LUF in the hCG group.

The authors concluded that GnRH agonist was associated with higher rates of clinical pregnancy and live birth compared to standard hCG treatment.

The patients in this study were not randomized to the treatment. This means that there could be underlying factors that affect the results. A randomized study will be important to fully understand what patients will benefit most from GnRH-a treatment.

If you have any concerns regarding infertility treatment protocols please discuss this with your physician.