Is the Flexible GnRH Antagonist Protocol Better Suited for Fresh eSET Cycles

Abstract Objective This study was performed to evaluate the efficacy of the flexible GnRH antagonist protocol in comparison with the long GnRH agonist protocol in elective single embryo transfer (eSET) practice. It was conducted in a publicly funded in vitro fertilization program. Methods We performed a prospective cohort analysis of data from a private infertility clinic from August 2010 to August 2011. Three hundred fourteen women with normal ovarian reserve and undergoing fresh eSET cycles were included. Sixty-four women underwent follicular stimulation using a flexible GnRH antagonist protocol, and 250 underwent stimulation with a standard long mid-luteal GnRH agonist protocol. Results Implantation rates (35.9% in the GnRH antagonist group and 29.6% in the GnRH agonist group, P =0.5) and ongoing pregnancy rates (32.8% in the GnRH antagonist group and 28.8% in the GnRH agonist group, P =0.5) were equivalent in both groups. The duration of stimulation (9.8±2days vs. 10.7±1.8days, P P P P P =0.3). Conclusion In women undergoing in vitro fertilization, the flexible GnRH antagonist protocol yields implantation and ongoing pregnancy rates that are similar to the long GnRH agonist protocol, and requires lower doses of gonadotropins and a shorter duration of treatment. The flexible GnRH antagonist protocol appears to be the protocol of choice for an eSET IVF program.