Importance of early elevated maternal HbA1c levels in identifying adverse fetal and neonatal events

The aims of this study were to explore factors that associated with gestational diabetes mellitus (GDM), and to determine the relationship between early maternal HbA1c levels and adverse fetal or neonatal events, and to determine an optimal maternal glucose testing method in order to decrease the potential health risk for their offspring.

From December 2015 to May 2016, a total of 6744 pregnant women were enrolled from Shanghai First Maternal and Infant Hospital affiliated to Tongji University prospectively in the nested case-control study. Each GDM case was matched with a healthy pregnant woman and followed up. Outcome analyses were conducted between GDM case and control groups, as well as elevated and normal maternal HbA1c levels, respectively.

A total of 1836 women were included in the adverse fetal and neonatal events examination. For pregnant women with early HbA1c ≥ 5.2%, the adjusted risk ratios (RR) of respiratory distress syndrome (RDS), pneumonia and jaundice were 4.37 (95%CI 1.54-12.35), 2.03 (95%CI 1.24-3.33) and 1.49 (95%CI 1.01-2.20), respectively. After treatments, the frequency for the majority of events in GDM group was similar to that of healthy pregnant women. Moreover, the area under the curve (AUC) of early maternal HbA1c in predicting potential RDS is 0.734. HbA1c ≤ 4.9% excluded for RDS.

Compared with women with normal HbA1c, those with an early elevated HbA1c level were more likely to develop adverse events, including RDS, pneumonia and jaundice. Early HbA1c testing can be used as an auxiliary method identifying potential RDS.