Association Between Glycemic Variability, HbA1c, and Large-for-Gestational-Age Neonates in Women With Type 1 Diabetes

Fetal exposure to hyperglycemia is a major determinant of large-for-gestational-age (LGA; birth weight >90th centile for gender) neonates (1), yet targets for glycemic control beyond the first trimester in type 1 diabetes (T1D) pregnancy remain controversial. As HbA1c represents a summary measure of glycemic control, it might not adequately reflect acute glucose fluctuations or glycemic variability (GV) that contributes to excess fetal growth. Moreover, neonates born to women who attain HbA1c <6% (42 mmol/mol) in the third trimester of pregnancy have an LGA prevalence of 25% (2), with associated adverse perinatal outcomes (3). In contrast to HbA1c, continuous glucose monitoring (CGM) allows precise observation of GV. Several studies have demonstrated an association between higher GV and increased birth weight (1,4,5). The capability of GV compared with HbA1c to identify women likely to have LGA neonates is, however, unclear. We evaluated the association between various measures of GV, HbA1c, and LGA neonates in T1D pregnancy. Twenty-one pregnant women with T1D were recruited over a 2-year period, and measurements of HbA1c and GV (EasyGV, University …