The associations between maternal glycolipid metabolism and fetal growth in term births.

This retrospective cohort study of 8,446 term pregnancies investigated the associations between maternal glycolipid metabolism and fetal growth. Neonates were classified as SGA, LGA, or AGA. Maternal triglycerides (TG), fasting plasma glucose (FPG), and the Triglyceride-Glucose (TyG) index were examined in relation to birth weight and SGA/LGA risks across trimesters using linear regression and generalized linear models. Group-based trajectory modeling was applied to the TyG index to identify metabolic patterns, and restricted cubic spline analyses assessed nonlinear associations between the third-trimester TyG and abnormal fetal growth. Higher maternal TG, FPG, and the TyG index were associated with increased birth weight and elevated LGA risk, with effects stronger in the GDM group than in the non-GDM group. Elevated TyG levels were consistently linked to reduced SGA risk and progressively higher LGA risk across trimesters, with LGA odds ratios of 1.32, 1.66, and 2.55 for the first, second, and third trimesters, respectively. Restricted cubic spline analyses revealed a J-shaped relationship between the third-trimester TyG and abnormal fetal growth. These findings indicate that maternal glycolipid metabolism influences fetal growth, with the TyG index serving as an integrated marker of maternal triglyceride-glucose status.