Comparisons of GnRH Antagonist versus GnRH Agonist Protocol in Supposed Normal Ovarian Responders Undergoing IVF: A Systematic Review and Meta-Analysis

Objective: To evaluate the effectiveness and safety of GnRH antagonist and GnRH agonist in supposed normal ovarian responders undergoing IVF. Methods: Data from 6 databases were retrieved for this study. The RCTs of GnRH agonist and GnRH antagonist use during IVF-EF therapy for patients with supposed normal ovarian response were included. A meta-analysis was performed with Revman 5.1software. Results: Twenty-three RCTs met the inclusion criteria. The number of stimulation days (mean difference (MD): -0.66, 95% confidence interval (CI): -1.04 similar to-0.27), Gn amount (MD: -2.92, 95% CI: -5.0 similar to-0.85), E2 values on the day of HCG (MD: -330.39, 95% CI: -510.51 similar to-150.26), Number of oocytes retrieved (MD: -1.33, 95% CI: -2.02 similar to-0.64), clinical pregnancy rate (odds ratio (OR): 0.87, 95% CI: 0.75-1.0), and ovarian hyperstimulation syndrome (OHSS) incidence (OR: 0.59, 95% CI: 0.42 similar to 0.82) were significantly lower in GnRH antagonist protocol than GnRH agonist protocol. However, the endometrial thickness on the day of HCG (MD: -0.04, 95% CI: -0.23 similar to 0.14), the ongoing pregnancy rate (OR: 0.87, 95% CI: 0.74 similar to 1.03), live birth rate (OR: 0.89, 95% CI: 0.64 similar to 1.24), miscarriage rate (OR: 1.17, 95% CI: 0.85 similar to 1.61), and cycle cancellation rate (OR: 1.11, 95% CI: 0.90 similar to 1.37) did not significantly differ between the 2 groups. Conclusions: During IVF treatment for patients with supposed normal responses, the incidence of OHSS were significantly lower, whereas the ongoing pregnancy and live birth rates were similar in the GnRH antagonist compared with the standard long GnRH agonist protocols.