Exploratory Analysis of Glycemic Control and Variability Over Gestation Among Pregnant Women with Type 1 Diabetes

In exploratory analyses, we evaluated glycemic variability (GV) and gestational outcomes in pregnant women (n = 28) with type 1 diabetes (T1D). Gestational age at delivery was higher for women with lower glycemic measures, including estimated HbA1c (eHbA1c) (0.14% decrease in HbA1c per 1-week greater gestational age, P = 0.0035), mean sensor glucose (-3.9 mg/dL P = 0.0039), time spent >140 mg/dL (-3.1%, P = 0.0029), and higher time in range (TIR) of 63-140 mg/dL (3.2%, P = 0.0029). Third trimester measured HbA1c was significantly associated with gestational age at delivery (P = 0.0081). Preeclampsia was associated with less TIR in first (50.5% vs. 69.9%, P = 0.0034) and second trimesters (47.1% vs. 66.7%, P = 0.0025), but not with measured HbA1c. There were significant differences in other markers of GV (continuous overall net glycemic action, high blood glucose index, J-index, mean amplitude of glycemic excursions) with infant birth weight and gestational age at delivery. Thus, multiple markers of glycemia and GV were associated with gestational health outcomes in T1D pregnancies in this pilot study. Clinical Trial Registration number: NCT02556554.