1430-P: Time Trends in Pregnancy-Related Outcomes among U.S. Women with Type 1 Diabetes Mellitus, 2004-2017

Objective: To examine a knowledge gap in U.S pregnant women with type 1 diabetes mellitus for time trends in maternal characteristics (i.e., maternal body mass index (BMI), nephropathy and gestational weight gain); treatment (i.e., glycemic control, insulin pumps and continuous glucose monitors (CGMs) use); and delivery outcomes (i.e., gestational age at delivery, birth weight and mode of delivery).

Research Design and Methods: We extracted clinical data from the medical records of 755 pregnant women seeking care at the Joslin and Beth Israel Deaconess Medical Center Diabetes in Pregnancy Program. Eligible women were 18 years old, had a singleton pregnancy, had clinically diagnosed type 1 diabetes mellitus and delivered from 2004-2017. We calculated means for continuous variables; proportions for categorical variables. We calculated P-values for trend over time. P- values < 0.05 were considered statistically significant.

Results: Between 2004 and 2017 the use of insulin pumps and CGMs increased from 38% to 71%, and 0% to 39%, respectively (p<0.0001). Despite these changes in treatment, HbA1c in each trimester was unchanged across the analysis period. The rates of nephropathy decreased from 4.6% to 0.4% (p=0.004). Excessive gestational weight gain increased (p=0.03). Gestation length also increased (p=0.008), as well as the rates of vaginal deliveries (p=0.007). Birth weight also appeared to increase over time marginally (p=0.06). However, the rates of macrosomia and large for gestational age (LGA) neonates, did not change.

Conclusion: Changes in treatment and guidelines may have improved specific pregnancy outcomes (i.e., gestation length and mode of delivery). However, other outcomes may need more attention, including excessive gestational weight gain, macrosomia, and LGA.