Progestin vs. Gonadotropin-Releasing Hormone Antagonist for the Prevention of Premature Luteinizing Hormone Surges in Poor Responders Undergoing in vitro Fertilization Treatment: A Randomized Controlled Trial

Objective: Progestin was recently used as an alternative of gonadotropin-releasing hormone (GnRH) analog for preventing premature luteinizing hormone (LH) surge with the aid of vitrification techniques, however, limited data were available about the potential of progestin in poor responders undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. We performed a randomized parallel controlled trial to investigate the difference of progestin and GnRH antagonist in poor responders. Methods: A total of 340 poor responders who met with Bologna criteria were randomly allocated into the progestin-primed ovarian stimulation (PPOS) group and GnRH antagonist group. Fresh embryo transfer was preferred in the GnRH antagonist group and freeze-all was performed in the PPOS group. The primary outcome was the incidence of premature LH surge, secondary outcomes were the number of retrieved oocytes, the number of viable embryos and the pregnancy outcomes. Results: The results showed that the incidence of premature LH surge in PPOS group was lower than that in antagonist group (0 vs. 5.88%, P < 0.05). In PPOS group, the average numbers of oocytes and viable embryos were comparable to those in GnRH antagonist group (3.7 ± 2.6 vs. 3.4 ± 2.4; 1.6 ± 1.7 vs. 1.4 ± 1.3, P > 0.05), the live birth rate was similar between the two groups (21.8 vs. 18.2%, RR 1.25 (95% confidence interval 0.73, 2.13), P > 0.05). Conclusions: The study demonstrated that PPOS had a more robust control for preventing premature LH rise than GnRH antagonist in poor responders, but PPOS in combination with freeze-all did not significantly increase the probability of pregnancy than GnRH antagonist protocol for poor responders.