Dynamic Changes of Kisspeptin during Controlled Ovarian Hyperstimulation (COH) in Polycystic Ovary Syndrome Patients and Its Correlation with COH Outcomes

Background Polycystic ovary syndrome (PCOS) is a common cause of anovulatory infertility in women, and patients often exhibit ovarian hyperresponse during controlled ovarian hyperstimulation (COH) in assisted reproductive technology. Kisspeptin is a key upstream regulator of the hypothalamic-pituitary-ovarian axis (HPOA). This study aims to explore the dynamic changes in serum and follicular fluid (FF) Kisspeptin levels during COH in PCOS patients and analyze their correlation with COH outcomes and pregnancy outcomes, in order to evaluate the potential value of Kisspeptin as a predictive biomarker. Methods This prospective cohort study included 100 patients undergoing IVF-ET treatment (50 in the PCOS group and 50 in the control group). Serum samples were collected at four time points during the COH cycle (the day of starting Gn treatment [dGn], the fifth day of Gn stimulation [dGn5], the day of hCG injection [dhCG], the day of oocyte pickup [dOPU]), and FF samples were obtained on dOPU. Kisspeptin levels were measured using ELISA. Baseline characteristics, Kisspeptin levels, COH outcomes, and pregnancy outcomes were compared between groups. Correlation and ROC curve analyses were performed. Results Serum and FF Kisspeptin levels were significantly higher in the PCOS group than in the control group at all time points ( P  < 0.001). Both groups showed significantly elevated Kisspeptin levels on dOPU compared with dGn ( P  < 0.001). Correlation analysis revealed that serum and FF Kisspeptin levels were positively correlated with AFC, AMH, E ₂ on dhCG, number of retrieved oocytes, and number of available embryos, but negatively correlated with the top-quality embryo (TQE) rate ( P  < 0.01). Although the PCOS group had higher numbers of retrieved oocytes and available embryos, their TQE rate, cumulative pregnancy rate (40.00% vs. 60.00%, P  = 0.046), and live birth rate (8.54% vs. 35.06%, P  = 0.014) were significantly lower than those of the control group. ROC curve analysis indicated that serum Kisspeptin levels on dOPU had a certain predictive value for pregnancy outcomes (AUC = 0.655, 95% CI: 0.547–0.763). Conclusion Kisspeptin may be involved in the pathological processes of ovarian hyperresponse and asynchronous follicular development in PCOS and possesses a certain predictive value for pregnancy outcomes. It provides an important basis for understanding the mechanisms of reproductive dysfunction in PCOS and for developing future multifactorial predictive models.