Association between the triglyceride-glucose index in third trimester pregnant women and neonatal birth weight

Objectives: Neonatal birth weight is a pivotal measure of fetal growth and development, with profound implications for an infant's immediate health and long-term well-being. The triglyceride-glucose (TYG) index, a marker of insulin resistance and metabolic health, has become an essential tool for evaluating maternal metabolic status during pregnancy. Recognizing the impact of metabolic abnormalities on fetal development, this study aims to delineate the association between the TYG index in the third trimester and neonatal birth weight. Material and methods: Our study cohort comprised 475 neonates. We calculated the maternal TYG index in the third trimester and documented neonatal birth weights. Correlation and multivariate linear regression analyses were conducted to evaluate the association between the TYG index and neonatal weight. Subgroup analyses were further examined using multivariate logistic regression. Results: A significant positive correlation was observed between the TYG index and neonatal birth weight (r = 0.314, p < 0.001). The multivariate linear regression analysis substantiated this association, revealing that an increment in the TYG index was associated with an average neonatal weight increase of 227.22 grams (β: 227.22, 95% CI: 148.74 to 305.71, p < 0.001). Notably, this correlation was more robust in subgroups without GDM (β: 281.17, p = 0.002), among male neonates (β: 213.06, p = 0.003) and in mothers over the age of 31 (β: 253.58, p < 0.001). Conclusions: The TYG index during the third trimester of pregnancy is significantly and positively associated with neonatal birth weight, with particularly strong associations in specific subgroups. These insights imply that the TYG index could serve as a predictive biomarker for neonatal weight, offering potential benefits for managing pregnancy and neonatal health.