Abstract / Summary
Polycystic ovary syndrome (PCOS) is a common endocrine disorder in reproductive-aged women. Baseline hormone levels are routinely assessed ovarian responsiveness during assisted reproduction. However, the impact of baseline luteinizing hormone (LH) levels on IVF/ICSI outcomes in PCOS remains unclear. This study included 162 PCOS patients and 120 controls undergoing IVF/ICSI-ET. PCOS patients were stratified into high- and low-LH groups. Endocrine characteristics, ovarian stimulation response, embryological parameters, routinely assessed endometrial parameters, and pregnancy outcomes were compared. A PCOS rat model was established to evaluate ovarian expression of FSHR and LHR. Baseline characteristics were comparable among groups except for higher BMI, testosterone, and AMH levels in PCOS patients. Ovarian stimulation duration, embryo quality, and high-quality embryo rates were similar. The high-LH PCOS group showed higher AFC, lower gonadotropin requirements, and elevated estradiol on trigger day, indicating enhanced ovarian responsiveness. However, fertilization, biochemical pregnancy rate, clinical pregnancy rate, and live birth rate did not differ significantly. Miscarriage risk was increased in PCOS, particularly in the low-LH subgroup. Logistic regression identified BMI and AMH, but not LH, as independent predictors of clinical pregnancy. In PCOS rats, FSHR expression decreased while LHR increased in ovarian granulosa cells, indicating local remodeling of gonadotropin receptor expression. In patients with PCOS undergoing IVF/ICSI-ET, baseline LH levels were associated with ovarian responsiveness but did not significantly affect fertilization, clinical pregnancy, or live birth outcomes. Compared with baseline LH, BMI and AMH may have greater clinical relevance for predicting clinical pregnancy. Altered ovarian granulosa cells of PCOS rats further suggest dysregulation of local gonadotropin signaling under PCOS conditions. Not applicable.