Objective To evaluate the association of serum irisin, together with reproductive endocrine and metabolic indicators, with clinical pregnancy outcomes following in vitro fertilization and embryo transfer (IVF-ET) in women with polycystic ovary syndrome (PCOS). Methods This single-center retrospective cohort study included 92 infertile PCOS patients who underwent their first IVF-ET treatment at our hospital from February 2022 to February 2024. Available baseline data, IVF-related treatment parameters, reproductive endocrine and metabolic indicators were retrospectively collected from the medical records, and pregnancy outcomes were followed up. Univariate analysis and multivariate logistic regression models were used to evaluate independent factors affecting pregnancy outcomes. Receiver operating characteristic (ROC) curve analysis was conducted to assess the predictive value of related indicators. Results The pregnancy success group (n=44) was younger, required a lower total dose of gonadotropins (Gn), and retrieved more oocytes (P<0.05). Regarding reproductive endocrine parameters, the success group had higher levels of follicle-stimulating hormone (FSH), progesterone (P), and sex hormone-binding globulin (SHBG), and a lower luteinizing hormone (LH)/FSH ratio (P<0.05). Metabolically, the success group showed significantly lower fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), but higher high-density lipoprotein cholesterol (HDL-C) levels compared with the failure group (P<0.001). Multivariate logistic regression indicated that LH/FSH ratio (OR = 0.616), free testosterone index (FTI, OR = 0.363), irisin (OR = 0.401), and Gn dosage (OR = 0.445) were independent factors associated with lower odds of clinical pregnancy success (P<0.05). ROC curve analysis suggested that LH/FSH ratio, free testosterone index (FTI), irisin, and Gn dosage had moderate predictive value for pregnancy outcomes. Conclusion The reproductive endocrine and metabolic characteristics of PCOS patients partially influence pregnancy outcomes following IVF-ET. Among the available endocrine, metabolic, and treatment-related indicators, LH/FSH ratio, FTI, irisin, and Gn dosage may serve as reference indicators for predicting IVF-ET pregnancy outcomes, suggesting that a more favorable endocrine and metabolic profile may be related to improved clinical pregnancy probability.