Pregnancies associated with diabetes are at high risk of adverse health outcomes. We examined associations between indices of glycemia and GV, assessed by continuous glucose monitoring, and maternal and fetal outcomes in women with T1D.

Women with T1D were stratified to groups during preconception or the 1st trimester: (1) CGM Alone (n=13): women without Apple devices, or (2) CGM Share (n=15, DexCom, San Diego, CA): women with iPhone and followers with data viewing devices. Association between change in GV indices over time and gestational outcomes were measured with linear mixed models.

Preeclampsia developed in 28.6% (8/28) of women. Preeclampsia was significantly associated with higher estimated A1C, mean sensor glucose, and time spent >140 mg/dL, and with lower time spent <65 mg/dL and 65-140 mg/dL (Table 1). Gestational age at delivery was 36.7 ± 1.7 weeks (mean ± SD). Gestational age at delivery was associated with lower estimated A1C (0.11% decrease A1C per 1 week increased gestational age, p=0.02), mean sensor glucose, and time spent >140 mg/dL, and with higher time in range (Table 2). There were no associations found between GV indices and cesarean delivery, delivery <37 weeks, large-for-gestational age infants, birth weight, and neonatal hypoxemia.

Preeclampsia and gestational age at delivery were associated with worse A1C and CGM metrics, but not with GV indices.

S. Polsky: Consultant; Self; Jaeb Center for Health Research. Research Support; Self; Barbara Davis Center for Diabetes, Children's Diabetes Foundation, Dexcom, Inc., Eli Lilly and Company, JDRF, Leona & Harry Helmsley Charitable Trust, National Institute of Diabetes and Digestive and Kidney Diseases, Sanofi US. L. Pyle: None. R. Garcetti: None. P. Joshee: None. J.K. Demmitt: None. T.B. Vigers: None. J.K. Snell-Bergeon: None.


Dexcom, Inc.; National Center for Research Resources/Colorado Clinical and Translational Science Institute (UL1RR025780)

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