Functional analysis of daily glycemic profiles and excessive fetal growth in pregnant patients with well-controlled type 1 diabetes: Retrospective cohort.

Aims: The study objective was to compare daily glycemic profiles throughout gestation between the mothers of large-for-gestational-age (LGA) and non-LGA newborns in patients with type 1 diabetes (T1D).

Methods: We selected 102 eligible pregnant women who were treated with sensor-augmented pumps in our single-center retrospective cohort study. We used functional data analysis to compare glycemic control across gestation.

Results: Median HbA1c values in the first, second, and third trimester were 6.23 %, 5.49 %, and 5.75 % respectively. Median time-in-range (TIR) exceeded 70 % in each trimester (72.4 %, 72.5 %, and 75.9 %, respectively). From 59 % up to 77 % of women met the criteria for well-controlled T1D defined by the mean HbA1c and TIR in each trimester. Despite that, 27 % (28/102) of pregnancies were complicated by LGA. Mothers of LGA infants had significantly increased HbA1c levels and decreased TIR values in the second and third trimesters. The most significant differences in daily mean glucose values between LGA and non-LGA newborns' mothers occurred between 26 and 32 weeks of pregnancy. These discrepancies were noted in daytime glucose values rather than nocturnal and fasting glucose levels.

Conclusions: Mothers of LGA newborns present significantly worse glycemic control. Our findings may emphasize the need for more rigorous daytime glycemic control.