Association of Triglyceride-Glucose Index with Risk of Large for Gestational Age: A Prospective Cohort Study

BACKGROUND: To evaluate the association of the baseline triglyceride-glucose (TyG) index in the first trimester of pregnancy with the risk of large for gestational age (LGA) in Southeast Chinese pregnant women. METHODS: A prospective birth cohort study recruiting 12,108 pregnant women at their first prenatal visit before 13 gestation weeks was conducted in 2019–2022. Baseline characteristics were collected from medical records or using questionnaires and blood samples were collected in the first trimester. The TyG index was obtained through the formula: ln[triglyceride (mg/dl)×fasting plasma glucose (mg/dl)/2]. The binary logistic regression model was performed to calculate the odds ratio (OR) and 95% confidence intervals (CI) to reveal the relationship between TyG index and LGA. Receiver-operating characteristic curve analysis was conducted to evaluate the ability of the TyG index to predict the risks of LGA. RESULTS: The overall incidence of LGA in the current study was 11.4% and the incidence of LGA increased with the baseline TyG index increasing. The risk of LGA was 2.05 (1.64, 2.57) for per unit increase in baseline TyG index. The increasing trend was found across the TyG index quartiles and the highest TyG quartiles raised the risk of LGA to 1.86 (95% CI: 1.51, 2.27) compared to the bottom TyG quartiles after full adjustment. The risk of LGA remained positive after stratification analysis. The AUC was 0.584 (95% CI: 0.569~0.600) in the entire subject, and the threshold was 8.34, with a sensitivity of 0.74 and specificity of 0.38. CONCLUSION: The findings suggested that a higher TyG index in the first trimester was independently associated with higher risk of LGA and high TyG index in the first trimester may play as a early predictor for LGA.