Non‐Linear Association Between Maternal Body Mass Index and Clinical Outcomes in Single Euploid Embryo Transfer: A Retrospective Cohort Study of 4235 Cycles

作者：Xi Cheng, Yueqi Leng, Can Wang, Lixue Chen, Mengjie Fan, Dan Mo, Meng Li, X H Chen, Heng Pan, Ping Zhou, Rong Li · 发表于：Diabetes Obesity and Metabolism · 年份：2026 · DOI：10.1111/dom.70736 · 研究领域：Ovarian function and disorders、Assisted Reproductive Technology and Twin Pregnancy、Reproductive Biology and Fertility

ABSTRACT Aims To investigate the associations between maternal body mass index (BMI) and pregnancy outcomes in single euploid frozen embryo transfer cycles. Materials and Methods This single‐center retrospective study analysed 4235 single euploid blastocyst transfer (SEBT) cycles performed between January 2018 and December 2024. Clinical outcomes were analysed using generalized estimating equations to assess the impact of BMI categories (underweight, normal, overweight, obese). Restricted cubic splines and Random forest models were employed to characterize the association between continuous BMI and clinical outcomes. Results Clinical pregnancy rates were significantly lower in underweight (34.6%; aOR 0.66, p = 0.001) and obese women (37.5%; aOR 0.69, p = 0.014) than in normal‐weight women (44.5%), whereas no significant difference was observed in the overweight group. Obesity was associated with increased odds of clinical miscarriage (aOR 2.17, p = 0.006) and preterm birth (aOR 3.05, p = 0.002), while underweight status had no significant effect on either outcome. Accordingly, live birth rates were reduced across all abnormal BMI categories, with the strongest effect observed in obese women (aOR 0.58, p < 0.001), followed by underweight (aOR 0.69, p = 0.006) and overweight women (aOR 0.85, p = 0.048). GEE‐based restricted cubic spline analyses showed significant inverted U‐shaped associations of maternal BMI with clinical pregnancy and live birth, with peak odds at BMI 21....