High maternal HbA1c is associated with overweight in neonates.

Abstract

Introduction: The aims of this study were to determine the prevalence of women with gestational diabetes mellitus (GDM) not obtaining HbA1c within the normal range (≤ 5.6%) before delivery and to examine whether elevated HbA1c values are associated with an increased risk of large for gestational age (LGA) infants.

Material and methods: A population of 148 women with singleton pregnancies who had been diagnosed with GDM < 34 weeks, and who had a minimum of two HbA1c tests with a ≥ 3 week interval. They were divided into those obtaining a HbA1c ≤ 5.6%, and those who did not before delivery and further stratified according to baseline HbA1c ≤ or > 5.6%. The primary outcome was LGA infants.

Results: A total of 51 (34%) women did not obtain a HbA1c ≤ 5.6% before delivery. The median HbA1c before delivery was 5.9% versus 5.3% in the two groups. At baseline, body mass index and HbA1c were higher in the women not obtaining the goal (30.9 versus 27.8 kg/m², 5.9% versus 5.1%, both p < 0.01). Women with an elevated HbA1c before delivery had a higher prevalence of LGA infants (adjusted odds ratio (OR) 3.1 (95% confidence interval (CI) 1.3-7.6) and neonatal hypoglycaemia (adjusted OR 6.2 (95% CI 1.3-29.0). Other pregnancy outcomes were similar in the two groups. Stratification according to baseline HbA1c did not seem to change the result.

Conclusion: Women with GDM not obtaining HbA1c within the normal range before delivery had a threefold increased risk of having an LGA infant and a sixfold increased risk of neonatal hypoglycaemia.

Funding: not relevant.

Trial registration: not relevant.