Association between maternal normal range HbA1c values and adverse birth outcomes

Abstract

Context: Higher blood glucose level during gestational periods has been consistently associatedwith increased risk of adverse birth outcomes. Evidence regarding the association between higherglycated hemoglobin A1c (HbA1c) within the normal range and adverse birth outcomes is limited.Objective: We aimed to examine the association between HbA1c within the normal range andthe risk of adverse birth outcomes.Design and Setting: The data were abstracted from the Information System of GuangdongWomen and Children Hospital, China, from September 2014 to March 2018.Patients: A total of 5658 pregnant women with normal gestational HbA1c were included in thisanalysis.Main Outcome Measures: The adverse birth outcomes include preterm birth, macrosomia, andlarge for gestational age (LGA).Results: Among 5658 subjects, the rates of preterm birth, macrosomia, and LGA were 4.6%(261/5658), 3.5% (200/5658), and 5.7% (325/5658), respectively. The results of multivariatelogistic regression model showed that each 1% increase in maternal HbA1c was positivelyassociated with increased risks of preterm birth (OR 1.58; 95% CI, 1.08-2.31), macrosomia(OR 1.70; 95% CI, 1.10-2.64), and LGA (OR 1.38; 95% CI, 0.98-1.96). The association betweengestational HbA1c and preterm birth was more evident among women with prepregnancy bodymass index (BMI) = 24 kg/m2.Conclusions: Gestational higher HbA1c level within the normal range is an independent riskfactor for preterm birth, macrosomia, and LGA. Intervention for reducing HbAc1 may help toprevent adverse birth outcomes.