Differences in Maternal and Fetal Outcomes by CGM Use in a T1D Specialty Clinic

Pregnancies associated with T1D have increased risks of adverse maternal and fetal outcomes, though continuous glucose monitoring (CGM) has been associated with significant reductions in the latter. We examined the clinical effectiveness of CGM in T1D pregnancies in a real-world setting.We retrospectively identified T1D pregnancies managed with either CGM therapy (n=81) or self-monitoring of blood glucose (SMBG) (n=77) over a 6.5-year period (1/1/14 to 8/31/20) at the Barbara Davis Center (BDC) for T1D and at obstetric practices in Colorado and Wyoming for obstetric care. CGM use was defined as ≥60% wear in the 2nd and 3rd trimesters of pregnancy. Baseline characteristics and maternal/fetal outcomes data were obtained from the BDC electronic medical record system and the vital statistics departments of Colorado and Wyoming. We used student’s t-test for continuous variables and chi-squared test for categorical variables to compare outcomes between groups.At baseline, a significantly higher proportion of CGM users were commercially insured and CGM users had a lower HbA1C at the first pregnancy visit (Table 1). CGM users had significantly lower levels of mean HbA1C in all trimesters, infants with lower mean birth weights (grams and percentile) and lower rates of large-for-gestational-age infants (Table 2).CGM use was associated with significantly improved maternal glucose control and neonatal outcomes in T1D pregnancies.View largeDownload slideView largeDownload slide DisclosureV. Gao: None. L. Sher: None. J. K. Snell-bergeon: Stock/Shareholder; Self; GlaxoSmithKline plc. E. Malecha: None. E. Westfeldt: None. P. Sullivan: Research Support; Self; Dexcom, Inc. S. Polsky: Advisory Panel; Self; Medtronic, Consultant; Self; National Institutes of Health, Research Support; Self; Dexcom, Inc., Eli Lilly and Company, JDRF, Medtronic, National Institute of Diabetes and Digestive and Kidney Diseases, Sanofi US, T1D Exchange.FundingDexcom, Inc. (IIS-2019-096)