(HealthDay News) — Elevated hemoglobin A1c (HbA1c) during the second and third trimesters correlates with increased risk of adverse pregnancy outcomes, according to a study published online November 3 in Diabetes Care.

Michael J.A. Maresh, MD, from St. Mary’s Hospital in Manchester, U.K., and colleagues conducted a prospective assessment involving 725 women with type 1 diabetes to examine the correlation between second and third trimester glycemic control and pregnancy outcomes. The women were categorized into five groups according to HbA1c values at 26 and 34 weeks’ gestation, with the lowest value of <6.0% as the reference. The women were also categorized into five groups based on average pre- and postprandial results from an eight-point capillary glucose profile the previous day.

The researchers found that an HbA1c of 6.0–6.4% at 26 weeks’ gestation correlated with increased risk of large for gestational age (odds ratio, 1.7). An HbA1c of 6.5–6.9% at 26 weeks’ gestation correlated with significantly elevated risk of preterm delivery, preeclampsia, need for neonatal glucose infusion, and a composite adverse outcome (odds ratios, 2.5, 4.3, 2.9, and 3.2, respectively). There was a progressive increase in these risks with increasing HbA1c. Similar results were seen at 34 weeks’ gestation. Less consistent trends were seen for the glucose profile.

“The data suggest that there is clinical utility in regular measurement of HbA1c during pregnancy,” the authors write.

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