Evaluating the Triglyceride–Glucose Index as an Early Screening Marker for Gestational Diabetes Mellitus

Background: Gestational diabetes mellitus (GDM) is a significant risk factor for adverse short- and long-term health outcomes for both the mother and infant. Although the oral glucose tolerance test (OGTT) is the gold standard for diagnosing GDM, its reproducibility remains debated. This study assessed the predictive accuracy of the triglyceride–glucose (TyG) index as an early biomarker for GDM.Methods: This prospective study was conducted at Al-Zahraa Teaching Hospital, Iraq, and included 150 singleton pregnant women at 7–14 weeks of gestation. Demographic and clinical data were collected. Maternal fasting blood tests were obtained for a lipid profile, fasting blood glucose, and HbA1c, and the TyG index was calculated. Predictive performance was evaluated using logistic regression and receiver operating characteristic (ROC) analysis.Results: The TyG index was positively associated with incident GDM (OR = 3.45, 95% CI: 2.22–5.36; p < 0.001). ROC analysis showed an area under the curve (AUC) of 0.89, with a cut-off value of 8.5 yielding 85.0% sensitivity and 78.0% specificity.Conclusion: An increased TyG index was significantly associated with the occurrence of GDM and may serve as an inexpensive tool for early screening.