The use of continuous glucose monitoring (CGM) during pregnancy in women with type 1 diabetes is associated with reduced hyperglycemia exposure to unborn infants as well as improved neonatal outcomes, according to a multicenter, open-label, randomized trial published in the Lancet.
Investigators randomly assigned 325 expectant mothers or women who were planning to become pregnant and who were taking insulin for type 1 diabetes to undergo capillary glucose monitoring with CGM (n=161) or without CGM (n=164) for 12 months.
Pregnant women who underwent CGM had a small yet significant difference in hemoglobin (Hb)A1c level compared with women not receiving CGM (mean difference -0.19%; 95% CI, -0.34 to -0.03; P =.0207). Additionally, participants receiving CGM had significantly fewer hyperglycemic episodes (27% vs 32%; P =.0279) and had better maintenance of target blood sugar range (68% vs 61%; P =.0034) than the non-CGM arm.
Despite the difference in duration of hyperglycemic events, patients receiving CGM vs those not receiving CGM experienced a similar number of severe hypoglycemic episodes (18 and 21, respectively) as well as comparable time in a hypoglycemic state (3% vs 4%, respectively; P =.10).
Participants who were assigned to the CGM group also had improved neonatal outcomes compared with controls. Specifically, CGM participants had a lower incidence of large for gestational age infants (odds ratio 0.51; 95% CI, 0.28 to 0.90; P =.0210), a lower rate of neonatal hypoglycemia (0.45; 0.22 to 0.89; P =.0250), fewer neonatal intensive care unit admissions >24 hours (0.48; 0.26 to 0.86; P =.0157), and a 1-day shorter hospital stay (P=.0091) than the non-GCM group.
According to the investigators, possible differences existed between the CGM data obtained with real-time sensors in the intervention group vs data obtained with masked sensors in the control group.
Because of the beneficial effects associated with using CGM, the investigators of this study suggest that, “national and international clinical guideline recommendations in type 1 diabetes in pregnancy should be revised to recommend offering CGM to pregnant women with type 1 diabetes using intensive insulin therapy in the first trimester.”