Estradiol-to-oocyte ratio as a prognostic biomarker of assisted reproductive outcomes in women with polycystic ovary syndrome: The impact of LH activity

Background Estradiol-to-oocyte ratio (EOR) was proposed as an assisted reproductive technology (ART) outcome predictor in general population. In women with polycystic ovary syndrome (PCOS), hormonal imbalances, especially estradiol and luteinizing hormone (LH) may affect the predictive value of EOR. Objectives We hypothesized that EOR plays a specific predictive role in PCOS and LH activity during ovarian stimulation modulates EOR and ART outcomes. Design Retrospective cross-sectional design. Methods The study included 276 patients with PCOS undergoing ART, stratified into four EOR groups: I (<466), II (467–683), III (684–886), and IV (>886). Additionally, patients were categorized based on LH activity during ovarian stimulation: no LH, recombinant LH, or LH-like activity. Key-outcome variables included counts of periovulatory follicles, retrieved oocytes, metaphase II (MII) oocytes, total number of embryos, good-quality (GQ) and frozen embryos, biochemical pregnancy rate (BPR), and clinical pregnancy rate (CPR). Comparisons were made across EOR and LH activity groups. Results Group I (lowest EOR) demonstrated the highest counts of MII oocytes, total number of embryos, GQ and frozen embryos. BPR and CPR showed a decreasing trend with increasing EOR, peaking in Group I. Multivariable analysis identified the absence of LH activity, higher periovulatory follicle count, and lower EOR as independent predictors of improved ART outcomes. The lowest EOR was observed in patients without LH supplementation, who achieved the best clinical results, though the differences between BPR and CPR were not statistically significant. Conclusion EOR is a valuable prognostic biomarker for ART outcomes in PCOS patients. Lower EOR is associated with more favorable outcomes. LH activity during stimulation influences EOR and ART success, particularly in patients with PCOS.