Evaluating the role of GnRH agonists in frozen embryo transfer cycles among polycystic ovary syndrome patients: a randomized clinical trial

Objective: This study aims to determine whether pretreatment with gonadotropin-releasing hormone agonists (GnRHa) can improve clinical outcomes. Trial design and methods: This single-blinded, noninferiority randomized clinical trial aimed to compare the effects of GnRHa pretreatment on pregnancy outcomes in patients with polycystic ovary syndrome (PCOS) undergoing frozen embryo transfer (FET). The study was conducted at the Avicenna Infertility Clinic (Tehran, Iran). A total of 284 participants were randomized into 2 groups of 142 individuals each; ultimately, 270 participants completed the trial – 133 in the GnRHa group and 137 in the no-GnRHa group. Outcomes included chemical, clinical, and ongoing pregnancy rates. Data were analyzed using t -tests and Fisher’s exact tests, with significance set at P < 0.05. Results: The chemical pregnancy rates in the intervention and comparison groups were 48.12% (95% CI: 39.80–56.54) and 45.98% (95% CI: 37.86–54.33), respectively, with no statistically significant difference between the groups ( P = 0.41). The clinical pregnancy rates were 42.84% (95% CI: 34.76–51.35) in the intervention group and 41.59% (95% CI: 33.69–49.98) in the comparison group, also showing no significant difference ( P = 0.55). The ongoing pregnancy rates were 28.60% (95% CI: 21.56–36.79) and 30.70% (95% CI: 23.07–39.10) in the intervention and comparison groups, respectively ( P = 0.52). Conclusions: The findings indicated that adding GnRHa to FET cycles in PCOS patients does not improve pregnancy outcomes, suggesting that clinicians may consider omitting GnRHa when appropriate. This supports more individualized, cost-effective treatment decisions without compromising effectiveness in routine fertility practice for selected cases.