Women with a nondiagnostic 75 g glucose tolerance test but elevated H b A 1c in pregnancy: An additional group of women with gestational diabetes

We examined whether pregnant women with a normal glucose tolerance test ( OGTT ) by N ew Z ealand ( NZ ) criteria, but elevated H b A 1c are a clinically important group with gestational diabetes ( GDM ). Eighty women with a normal OGTT and HbA1c > 40 mmol/mol, compared with others with GDM , had a significantly higher BMI and were more likely P acific. Pharmacotherapy was prescribed in 77.5%. Post‐partum OGTT and H b A 1c were abnormal in 9/43(20.9%) and 27/42(64.3%), respectively. In 1090 women being screened for GDM by OGTT , most women with GDM had an H b A 1c ≤ 40 mmol/mol. In the 22.1% of women with an H b A 1c > 40 mmol/mol, the OGTT was normal in 61.8%. For centres using H b A 1c to screen for underlying prediabetes/diabetes, these data show that a result >40 mmol/mol identifies women who are likely to require pharmacotherapy. An OGTT is still recommended to diagnose GDM , but these data raise questions about a possible role for H b A 1c in high risk women with a nondiagnostic OGTT .