GnRH antagonist protocol is associated with higher oocyte yield in young women at high risk for low oocyte retrieval: a retrospective study using three statistical methods.

Abstract

OBJECTIVE To study whether gonadotropin-releasing hormone (GnRH) antagonist protocol is associated with improved oocyte retrieval outcomes compared to progestin-primed ovarian stimulation (PPOS) protocol in young women at high predicted risk for low oocyte yield. DESIGN Retrospective cohort study applying Bayesian analysis before and after propensity score matching (PSM), and risk-based stratified subgroup analysis SUBJECTS: A total of 2,068 women aged ≤35 years undergoing their first IVF/ICSI cycle between January 2023 and April 2025, identified as high risk for low oocyte retrieval (predicted score ≥0.41) using a validated nomogram incorporating age, AMH, AFC, basal FSH, and FSH/LH ratio. EXPOSURE Ovarian stimulation with either a GnRH antagonist protocol or a PPOS protocol, with protocol selection based on clinical judgment and patient characteristics. MAIN OUTCOME MEASURES Incidence of low oocyte retrieval (<10 oocytes), and the number of oocytes retrieved. RESULTS Among 2,068 young women at high predicted risk for low oocyte yield, the GnRH antagonist protocol resulted in significantly better ovarian stimulation outcomes compared to the PPOS protocol. After PSM, the antagonist group had a higher mean number of oocytes retrieved (8.3 vs. 5.3; BF10 > 1028) and a higher oocyte retrieval rate (88.2% vs. 81.2%; BF10 > 103). The incidence of low oocyte retrieval (<10 oocytes) was significantly lower in the antagonist group (65.2% vs. 86.0%; BF10 > 1019). No significant differences were observed in embryo quality or fertilization rates. Risk-based stratified analysis showed that the GnRH antagonist protocol significantly reduced the incidence of low oocyte retrieval in low- to mid-risk groups (median OR 0.30-0.57, BF10 up to 647.8), while in the highest risk subgroup, PPOS showed a potential advantage. CONCLUSION The GnRH antagonist protocol is superior to PPOS in maximizing oocyte retrieval among young women at high predicted risk for poor ovarian response, highlighting the value of individualized risk-based stimulation strategies to improve clinical outcomes.