polycystic ovary syndrome, insulin resistance, oral glucose tolerance test, embryo morphological assessment, in vitro fertilization, Diseases of the endocrine glands. Clinical endocrinology, RC648-665

ObjectiveTo explore the effects of insulin resistance (IR) on embryo quality and pregnancy outcomes in women with or without polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).MethodsA retrospective cohort study concerning patients with/without PCOS who received gonadotropin-releasing hormone (GnRH)-antagonist protocol for IVF/ICSI from January 2019 to July 2022 was conducted. All the patients included underwent oral glucose tolerance test plus the assessment of insulin release within 6 months before the controlled ovarian stimulation. The Matsuda Index was calculated to diagnose IR. Two populations (PCOS and non-PCOS) were included and each was divided into IR and non-IR groups and analyzed respectively. The primary outcome was the high-quality day 3 embryo rate.ResultsA total of 895 patients were included (751 with PCOS and 144 without PCOS). For patients with PCOS, the IR group had a lower high-quality day 3 embryo rate (36.8% vs. 39.7%, p=0.005) and available day 3 embryo rate (67.2% vs. 70.6%, p