Impact of Insulin Resistance on Ovarian Sensitivity and Pregnancy Outcomes in Patients with Polycystic Ovary Syndrome Undergoing IVF

Background: Ovarian sensitivity index (OSI) is an accurate index to reflect the ovarian sensitivity to exogenous gonadotropins in in vitro fertilization (IVF). How insulin resistance (IR) affects OSI and pregnancy outcomes during IVF remains unclear. Methods: This was a large retrospective, cohort study. A total of 2055 women with polycystic ovary syndrome (PCOS) undergoing the first fresh IVF cycle were enrolled. They were grouped into terciles based on the homeostasis model assessment of insulin resistance (HOMA-IR) values as control, medium and IR group for comparison. Multivariate regression analysis was also conducted. Results: HOMA-IR had a significantly negative impact on OSI (adjusted β = −0.24; 95% CI, −0.35 to −0.13), especially in lean patients with an adjusted β of −0.33 (95% CI, −0.51 to −0.16). The interaction analysis revealed an interactive association between HOMA-IR and body mass index (BMI) (p = 0.017). IR was related to an increased early miscarriage risk independently with an odds ratio (OR) of 2.21 (95% CI, 1.13 to 4.33), without significant impact on pregnancy and live birth rate. Conclusion: IR decreased the ovarian response in PCOS patients undergoing IVF, especially in the lean subgroup. IR may result in a higher risk of early miscarriage, but did not impair pregnancy and live birth rate.