(HealthDay News) — An HbA1c threshold of 5.9% or greater can identify all women with gestational diabetes in early pregnancy, according to a study published online in Diabetes Care.

Ruth C.E. Hughes, MBBCh, from the University of Otago in New Zealand, and colleagues analyzed data from a group of women who completed an early oral glucose tolerance test (OGTT) and HbA1c tests. Pregnancy outcome data were also assessed.

In 16,122 women, HbA1c was measured at a median of 47 days’ gestation. Twenty-three percent of those offered (n=974) took an early OGTT, and in this subset all 15 cases of diabetes were identified with HbA1c ≥5.9%. For gestational diabetes before 20 weeks, this threshold was 98.4% specific (positive predictive value, 52.9%). 

Excluding the women referred for gestational diabetes, women with HbA1c of 5.9% to 6.4% had poorer pregnancy outcomes than those with HbA1c <5.9% (n=8,174): relative risk of major congenital anomaly was 2.67; preeclampsia, 2.42; shoulder dystocia, 2.47; and perinatal death, 3.96.


Continue Reading

“HbA1c measurements were readily performed in contrast to the low uptake of early OGTTs,” the researchers wrote.

Reference

  1. Hughes RCE et al. Diabetes Care. 2014;doi:10.2337/dc14-1312.