Abstract / Summary
Abstract Purpose To investigate whether insulin resistance is associated with live birth outcomes in non-PCOS infertile women (PCOS, polycystic ovary syndrome) undergoing their first frozen-thawed single blastocyst transfer, and to evaluate the dose-response relationship between HOMA-IR (homeostasis model assessment of insulin resistance) and live birth. Methods This retrospective cohort study included 349 non-PCOS infertile women who underwent their first frozen-thawed single blastocyst transfer. Patients were divided into insulin resistance group (HOMA-IR ≥ 2.71, n = 142) and non-insulin resistance group (HOMA-IR < 2.71, n = 207) based on the homeostasis model assessment of insulin resistance index. The primary outcome was live birth rate; secondary outcomes included clinical pregnancy rate and early miscarriage rate. Hierarchical multivariate logistic regression analysis was used to adjust for confounders, restricted cubic spline analysis was performed to evaluate the dose-response relationship, and ROC curve analysis was used to assess the predictive value of HOMA-IR. Sample size was estimated based on previous studies. A two-sided P < 0.05 was considered statistically significant, with Bonferroni correction applied for secondary outcomes. Model fit was adequate based on AIC and Hosmer-Lemeshow test. Results The live birth rate was 38.0% (54/142) in the IR group and 37.7% (78/207) in the non-IR group (P = 1.000). After adjusting for age, BMI, blastocyst quality, and endometrial thickness, IR was not an independent predictor of live birth (OR = 1.16, 95% CI: 0.71–1.92, P = 0.549). Restricted cubic spline analysis showed no significant dose-response relationship between HOMA-IR and live birth. ROC curve analysis showed that HOMA-IR had poor predictive value for live birth (AUC = 0.533, 95% CI: 0.469–0.598). Conclusion In non-PCOS patients undergoing their first FET (frozen-thawed embryo transfer) cycle, insulin resistance is not associated with live birth outcomes. This null finding suggests that the impact of IR on reproductive outcomes may be population-specific and of limited clinical significance in first-cycle patients without prior failure.