Continuous glucose monitoring parameters in pregnancy-related complications in patients with type 1 diabetes: a retrospective cohort study

Abstract

Introduction: Continuous glucose monitoring (CGM) improves pregnancy outcomes in patients with type 1 diabetes (T1D).

Objectives: The primary study objective was to analyze associations between numerous novel CGM parameters and neonatal complications; large-for-gestational-age (LGA) neonates, hypoglycemia, hyperbilirubinemia, transient breathing disorders, preterm births, and pre-eclampsia.

Patients and methods: We conducted a single-center retrospective cohort study. We recruited 102 eligible pregnant women with T1D who were treated with sensor-augmented pumps with suspend-before-low function from the first trimester. Pregnant patients were admitted for at least one control hospital visit in each trimester of gestation to undergo anthropometric and laboratory measurements, and collection of sensor data.

Results: The mean HbA1c (%) [I: 6.23 (5.91 - 6.90); II: 5.49 (5.16 - 5.90); III: 5.75 (5.39 - 6.29)] and time-in-range (%) [I: 72.4 (67.3 - 80.3); II: 72.5 (64.7 – 79.6); III: 75.9 (67.1 - 81.4) values met the criteria of well-controlled T1D in each trimester of pregnancy. Nonetheless, we noted 27% of LGA births, 25% of neonatal hypoglycemia, 33% of hyperbilirubinemia, and 13% of preterm births. Worse glycemic control and more glycemic fluctuations in the second and third trimesters were mainly associated with increased risk of LGA, transient breathing disorders, and hyperbilirubinemia.

Conclusions: CGM parameters - MODD, HBGI, GRADE, or CONGA are significantly associated with the increased risk of LGA, transient breathing disorders, and hyperbilirubinemia in patients with T1D. However, we did not find evidence that novel CGM indices could be more effective in predicting those events compared to commonly used CGM parameters or HbA1c.