Large-for-gestational-age (LGA) births remain a frequent complication in pregnancies with type 1 diabetes (T1D), even with advanced glucose monitoring and insulin delivery. Findings from a retrospective cohort study were presented at the European Association for the Study of Diabetes (EASD) 2025 conference.

The study, conducted at Poznan University of Medical Sciences, evaluated 173 pregnant women with T1D treated with sensor-augmented insulin pumps from the first trimester. Most women maintained satisfactory glycemic control, with HbA1c values close to recommended targets in all trimesters. However, key differences emerged between mothers of LGA and appropriate-for-gestational-age (AGA) newborns.

Women with LGA outcomes had higher HbA1c levels during the second and third trimesters, alongside consistently lower TIR values. While total daily insulin and bolus doses did not differ, basal insulin requirements were significantly higher in LGA pregnancies during weeks 14–17 and 26–36. An elevated basal-to-bolus ratio was also observed across multiple gestational periods.

These findings suggest that closer monitoring of HbA1c, TIR, and basal insulin dosing during mid-to-late pregnancy may help mitigate the risk of LGA births in women with T1D.