Elevated triglyceride glucose-body mass index is associated with a higher risk of reduced cumulative live birth and adverse pregnancy outcomes in women undergoing assisted reproductive technology: a retrospective cohort study

Background: Insulin resistance has been linked to adverse reproductive and pregnancy outcomes. The triglyceride glucose-body mass index (TyG-BMI) serves as a simple and cost-effective surrogate marker of insulin resistance. This study aimed to investigate the association between maternal TyG-BMI and cumulative live birth as well as pregnancy outcomes in women undergoing assisted reproductive technology. Methods: This retrospective cohort study included 53,393 women undergoing assisted reproductive technology at the Reproductive and Genetic Hospital of CITIC-Xiangya, China, between January 1, 2017, and March 31, 2023. Associations between baseline TyG-BMI and assisted pregnancy outcomes were estimated using modified Poisson regression and restricted cubic splines. Compared with women in the lowest TyG-BMI tertile (≤177), those in the highest tertile (>203) had a lower cumulative live birth rate (aRR 0.973; 95% confidence interval 0.956-0.991). Higher TyG-BMI was also associated with higher risks of first-trimester miscarriage (aRR, 1.090; 95% confidence interval 1.002-1.185), second- or third-trimester fetal loss (aRR 1.694; 95% confidence interval 1.481-1.938), preterm birth (aRR 1.244; 95% confidence interval 1.170-1.323), and macrosomia (aRR 2.352; 95% confidence interval 2.060-2.685). Conclusions: Higher maternal TyG-BMI is associated with reduced cumulative live birth rates and higher risks of adverse pregnancy outcomes including miscarriage, preterm birth, and macrosomia following assisted reproductive technology. TyG-BMI may be a potential and cost-effective marker associated with adverse reproductive outcomes in women undergoing fertility treatment. Clinical Trial Registration: https://www.clinicaltrials.gov, identifier NCT05404464.