Development and validation of a First Trimester Clinical Risk Score (FTRS) for predicting gestational diabetes mellitus in a low-resource setting: an observational cohort study

Background Several models have been developed for early prediction of gestational diabetes mellitus (GDM) during the first trimester; however, many rely on biochemical markers or are unsuitable for low-resource settings. This study aimed to develop and validate a simple first-trimester clinical risk score (FTRS) for early prediction of GDM using routinely available clinical variables. Methods In this prospective cohort study, 730 pregnant women presenting before 14 weeks’ gestation at a tertiary care teaching hospital in Eastern India were enrolled. GDM was diagnosed using the Diabetes in Pregnancy Study Group India (DIPSI) criteria based on a 75-g oral glucose challenge test performed at three time points during pregnancy. Eight clinical predictors were evaluated using multivariable Poisson regression. Equal- weighted and weighted FTRS models were developed and assessed using receiver operating characteristic (ROC) curve analysis. Results GDM developed in 271 (37.1%) participants. Eight clinical predictors were incorporated into the FTRS. The equal-weighted score (cut-off ≥ 3) achieved an area under the ROC curve (AUC) of 0.74, with 66.8% sensitivity and 82.9% specificity. The weighted score (cut-off ≥ 10) showed slightly better performance, with an AUC of 0.77, 70.2% sensitivity, and 83.4% specificity. Conclusion The first-trimester clinical risk score (FTRS) is a simple, practical, and non-invasive tool for early prediction of GDM using routinely available clinical variables. Its ease of application makes it particularly suitable for early risk stratification and targeted screening in low-resource settings.