HbA1c

This study evaluated the potential of hemoglobin A1c (HbA1c) as an early screening tool for identifying women at risk for gestational diabetes mellitus (GDM). Among 220 pregnant women tested at 16 weeks gestation, an HbA1c ≥5.7% (39 mmol/mol) was associated with altered glucose dynamics, impaired beta-cell function, and delayed glucose peak during an oral glucose tolerance test (OGTT). The HbA1c cutoff of 5.7% demonstrated high specificity for GDM diagnosis (0.96) and glucose-lowering treatment need (0.95), though its overall predictive accuracy was moderate. Elevated HbA1c was also linked to an increased risk of delivering large-for-gestational-age infants, independent of GDM status. These findings suggest that early HbA1c measurement reflects underlying glucose intolerance and beta-cell dysfunction, supporting its utility in early risk stratification for GDM.