- Early HbA1c levels may suggest hyperglycemia and increase risk of developing gestational diabetes mellitus (GDM).
Why this matters
- HbA1c is a measure of glycated hemoglobin, an indicator of glucose control in the prior 3-4 months.
- Fetal overgrowth may begin before the identification of GDM.
- HbA1c was higher in women with GDM throughout pregnancy compared with control participants (P<.03>
- Both groups followed similar patterns throughout pregnancy: HbA1c decreased slightly from first to second trimesters and tended to increase in the third trimester.
- There was a linear association between HbA1c at 8-13 weeks' gestation and GDM risk (P=.001).
- Sensitivity (47%; 95% CI, 34%-60%) and specificity (79%; 95% CI, 62%-88%) of HbA1c at 8-13 weeks' gestation to predict GDM using an HbA1c cutoff of 5.1%.
- Secondary analysis of data from a prospective case-control study, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singleton Cohort.
- Stored blood was used to measure HbA1c at different points during pregnancy to generate longitudinal trajectories of HbA1c across pregnancy.
- HbA1c compared between control participants (n=211) and women who were diagnosed with GDM (n=100).
- Funding: The Eunice Kennedy Shriver NICHD.
- Small sample size.