Elevated glycated hemoglobin predicts macrosomia among Asian Indian pregnant women (WINGS-9)

AIM: The aim of this study was to determine the optimal glycated hemoglobin (HbA1c) cut point for diagnosis of gestational diabetes mellitus (GDM) and to evaluate the usefulness of HbA1c as a prognostic indicator for adverse pregnancy outcomes. METHODS: HbA1c estimations were carried out in 1459 pregnant women attending antenatal care centers in urban and rural Tamil Nadu in South India. An oral glucose tolerance test was carried out using 75 g anhydrous glucose, and GDM was diagnosed using the International Association of the Diabetes and Pregnancy Study Groups criteria. RESULTS: GDM was diagnosed in 195 women. Receiver operating curves showed a HbA1c cut point of ≥ 5.0% (≥31 mmol/mol) have a sensitivity of 66.2% and specificity of 56.2% for identifying GDM (area under the curve 0.679, confidence interval [CI]: 0.655–0.703). Women with HbA1c ≥ 5.0% (≥31 mmol/mol) were significantly older and had higher body mass index, greater history of previous GDM, and a higher prevalence of macrosomia compared to women with HbA1c < 5.0% (<31 mmol/mol). The adjusted odds ratio for macrosomia in those with HbA1c ≥ 5.0% (≥31 mmol/mol) was 1.92 (CI: 1.24–2.97, P = 0.003). However, other pregnancy outcomes were not significantly different. CONCLUSION: In Asian Indian pregnant women, a HbA1c of 5.0% (31 mmol/mol) or greater is associated with increased risk of macrosomia.