Continuous glucose monitoring feedback in the subsequent development of
gestational diabetes: a randomised controlled trial in pregnant women
Abstract
Objective: To examine CGM feedback with the subsequent
development of gestational diabetes (GDM), maternal glycaemic control,
and glycaemic variability during pregnancy with randomisation 1:1 with
one study arm receiving CGM feedback by intermittent scanning (unblinded
group), versus masked feedback (blinded group). Design:
Prospective, single-center, randomized controlled trial
Setting: Single tertiary care hospital Population:
Pregnant women recruited in the first trimester of pregnancy
Methods: We assessed GDM and plasma glucose levels diagnosed by
the 75-g oral glucose tolerance test (OGTT) at 24-28 weeks as a primary
outcome. The secondary outcome was CGM-derived parameters of glycaemic
variability across the first (9-13 weeks), second (18-23 weeks), late
second and early third (24-31 weeks) and third trimester (32-33weeks).
Results: Over 47 months, 206 pregnant women were enrolled at
9-13 weeks. There were no significant differences with GDM outcomes,
fasting, 1-hour or 2-hour plasma glucose concentrations between study
arms. The unblinded group had higher %time-in-range in the first
(83.2% vs 78.1%; p=0.06), second [88.7% vs 80.5%; p=0.02] and
third trimester (90.2% vs 79.5%; p=0.07), compared to the blinded
group. Conversely, the unblinded group had lower %time-below-range in
the first trimester (15.4% vs 21.2%; p=0.06), and early second
trimester (8.8% vs 16.9%; p=0.05]. No significant differences were
observed with the %time-above-range, mean, standard deviation, Mean
Amplitude Glycaemic Excursion and % Coefficient Variation across all
trimesters. Conclusion: CGM feedback, coupled with better
glycaemic control (higher %TIR and low %TBR) indicates its’ potential
use in combination with appropriate patient education for promoting
better glucose control during pregnancy.