FPG

This study assessed biochemical predictors of gestational diabetes mellitus (GDM) and the need for glucose-lowering medication. In 574 pregnant women, those who developed GDM had higher early fasting plasma glucose (FPG), fasting insulin (FI), fasting C-peptide (FCP), and HbA1c levels compared to women with normal glucose tolerance (NGT). Higher FPG and FCP levels were strongly associated with GDM risk. Indices of glucose disposal based on C-peptide, particularly the modified QUICKIc index, showed better predictive accuracy for GDM (ROC-AUC 72.1%) and the need for pharmacotherapy (ROC-AUC 83.7%). Fasting glucose, C-peptide, and glycemic indices can effectively stratify GDM risk early in pregnancy.