The role of elagolix in ovulation suppression during controlled ovarian stimulation: a retrospective cohort study.

Objective: To compare in vitro fertilization treatment outcomes for the oral gonadotropin-releasing hormone (GnRH) antagonist elagolix (E) to the conventionally used injectable GnRH antagonist ganirelix (G) for achieving pituitary gonadotropin suppression during a controlled ovarian stimulation (COS) cycle.

Design: Retrospective cohort study.

Setting: Private university-affiliated fertility center.

Patients: One hundred and ninety-four infertility patients receiving either E or G for pituitary suppression during the COS cycle.

Exposure: Use of E for ovulation suppression during the COS cycle.

Main Outcome Measures: Biochemical pregnancy, sustained implantation, and cycle cancellation rates were the primary outcome measures. Secondary outcomes included miscarriage, fertilization, and blastulation rates.

Results: The groups did not differ in their baseline demographic characteristics (age, body mass index, hormone profiles, total dosage of gonadotropins, number of oocytes retrieved, and number of embryos transferred). The overall cycle cancellation rates were 7.0% and 4.9% for e and G, respectively, and the difference was not statistically significant. For the frozen embryo transfers, the biochemical pregnancy, sustained implantation, and miscarriage rates for E were 74.5%, 51.0%, and 31.6%, respectively. For G, these were 55.9%, 39.8%, and 28.8%. Out of these outcomes, only the biochemical pregnancy rates were significantly different. For the fresh embryo transfers, biochemical pregnancy, sustained implantation, and miscarriage rates for E were 33.3%, 33.3%, and 0.0%, and for G, they were 37.5%, 25.0%, and 33.3%. None of the differences reached significance.

Conclusions: The oral GnRH antagonist, E, may be as effective as the injected antagonist, G, regarding embryological and clinical outcomes and could offer a less invasive, more cost-effective, and "patient-friendly" approach to pituitary suppression for in vitro fertilization treatment.