1975-LB: A Randomized Trial of Real-Time Continuous Glucose Monitoring in Gestational Diabetes

Background: Gestational diabetes is common. Real-time continuous glucose monitoring (RT-CGM) may improve glycemia during pregnancy, but data is lacking. Methods: We conducted a randomized controlled study in which patients with GDM performed SMBG with RT or blinded CGM. This analysis compares CGM metrics at EGA 32 and 36 weeks (+/-10 days). Outcomes included CGM metrics (see table), A1c and diabetes medication use. Results: 107 participants with GDM enrolled (RT-CGM: N=53; SMBG: N=54). 35 SMBG participants withdrew, reporting desire for RT-CGM. Average EGA at CGM start was 30.2 (+/-1.7) weeks, age was 33.8 (+/-4.8) years, and 31% (RT-CGM) and 14% (SMBG) groups were on diabetes medication at screening. The 32-week CGM metrics for the groups were similar except mean glucose (RT-CGM=106.7 +/- 9 and SMBG=97.7 +/- 13, P=.01) and TBR54 (0.1 +/- 0.2) and 0.6 (+/- 1.2), P=0.08). 36-week mean glucose decreased for the RT-CGM group but increased for the SMBG group, and TBR54 was lower for the RT-CGM group (P=.03). A1c was similar between groups. Diabetes medication use at study end was 69% for RT-CGM and 32% for SMBG. Conclusions: RT-CGM and SMBG group indices were similar despite higher initial mean glucose and diabetes medication use. Glucose changes were slight when CGM was started at EGA of 30 weeks but desire for CGM was high. More studies are needed to evaluate if earlier RT-CGM use will significantly affect glycemic indices. Disclosure N.M. Ehrhardt: Advisory Panel; Bayer Inc., Dexcom, Inc. Research Support; Dexcom, Inc., Novo Nordisk. Advisory Panel; Novo Nordisk. Research Support; Merck & Co., Inc. E. Fay: None. G. Abdalla: None. P. Mandava: None. S.J. Fonda: None. Funding Investigator initiated grant DexcomIIS-2019-101