HbA1c during early pregnancy reflects beta-cell dysfunction in women developing GDM

Area of Science:

• Endocrinology
• Obstetrics
• Metabolic Disorders

Background:

• Gestational diabetes mellitus (GDM) poses risks for mother and child.
• Early identification of at-risk pregnancies is crucial for timely intervention.
• The accuracy of hemoglobin A1c (HbA1c) for early GDM risk stratification remains debated.

Purpose of the Study:

• To evaluate if HbA1c in early pregnancy reflects pathophysiological changes associated with GDM development.
• To assess the accuracy of HbA1c as a screening tool for identifying women at risk for severe hyperglycemia in pregnancy.

Main Methods:

• A cohort of 220 pregnant women had HbA1c and oral glucose tolerance tests (OGTT) at 16 weeks gestation.
• OGTT included multiple measurements of glucose, insulin, and C-peptide to assess insulin sensitivity and beta-cell function.
• Clinical follow-up continued until the end of pregnancy.

Main Results:

• Maternal HbA1c ≥5.7% was linked to altered glucose dynamics, impaired beta-cell function, and differences in disposition index.
• Higher fasting and mean glucose concentrations were observed in pregnancies with elevated HbA1c.
• HbA1c ≥5.7% showed high specificity for GDM and the need for glucose-lowering medication, and was associated with delivering large-for-gestational-age infants.

Conclusions:

• HbA1c measured before routine screening can indicate early pathophysiological derangements in glucose metabolism.
• HbA1c may be a valuable tool for early risk stratification of GDM.
• Early identification of GDM risk through HbA1c can potentially improve pregnancy outcomes.