Glycemic Variability in Type 1 Diabetes Mellitus Pregnancies—Novel Parameters in Predicting Large-for-Gestational-Age Neonates: A Prospective Cohort Study

Abstract

Pregnancies with type 1 diabetes mellitus (T1DM) have a high incidence of large-for-gestational-age neonates (LGA) despite optimal glycemic control. In recent years, glycemic variability (GV) has emerged as a possible risk factor for LGA, but the results of the conducted studies are unclear. This study analyzed the association between GV and LGA development in pregnancies with T1DM. This was a prospective cohort study of patients with T1DM who used continuous glucose monitoring (CGM) during pregnancy. Patients were followed from the first trimester to birth. GV parameters were calculated for every trimester using the EasyGV calculator. The main outcomes were LGA or no-LGA. Logistic regression analysis was used to assess the association between GV parameters and LGA. In total, 66 patients were included. The incidence of LGA was 36%. The analysis extracted several GV parameters that were significantly associated with the risk of LGA. The J-index was the only significant parameter in every trimester of pregnancy (odds ratios with confidence intervals were 1.33 (1.02, 1.73), 3.18 (1.12, 9.07), and 1.37 (1.03, 1.82), respectively. Increased GV is a risk factor for development of LGA. The J-index is a possible novel GV parameter that may be assessed in all three trimesters of pregnancy together with glycated hemoglobin and time-in-range.

Continuous glucose monitoring metrics in pregnancy with type 1 diabetes mellitus

“…For expectant mothers with type 1 diabetes, this might mean missed opportunities for timely interventions or adjustments in their diabetes management plan, potentially impacting both maternal and foetal health. Furthermore, the importance of consistent CGM use in pregnancy is underscored by the dynamic nature of glucose levels during this period[ 37 ].…”

“…The clinical implications of GV during pregnancy are profound. GV has been identified as a potential risk factor for pregnancy complications, such as large for gestational age (LGA) infants[ 37 ]. Studies have shown that women with GDM exhibit higher GV, as indicated by increased SD and mean amplitude of glycaemic excursion (MAGE) values[ 28 ].…”

Continuous Subcutaneous Infusion Versus Multiple Daily Injections of Insulin for Pregestational Diabetes in Pregnancy: A Systematic Review and Meta-Analysis

“…In addition, future studies should evaluate the timing of initiation and role of CSII versus MDI in reducing glycemic variability to improve time in range, including prevention of prandial hyperglycemia, in mitigating adverse pregnancy outcomes. 71…”

“…These aforementioned variables that contribute to the complexity of CSII use may ultimately contribute to fetal hyperinsulinemia, overgrowth, and resultant LGA compared to MDI users. 28,[69][70][71] However, the available data do not elucidate the relative contributions of these challenges with CSII therapy to the greater risk of LGA. Similarly, the available data do not account for the contribution of these complex CSII variables to fetal hyperinsulinemia and associated neonatal hypoglycemia risk in those who initiate CGM prior to pregnancy.…”