Whether T1DM and T2DM influence perinatal outcomes differently remains a critical question, and this study provides clear comparative evidence across all groups. Diabetology published a cohort study comparing outcomes in pregnancies complicated by T1DM and T2DM with outcomes in pregnancies without diabetes. 

The study used a single-center retrospective design from 2010 to 2019 and included 2,050 singleton pregnancies. This cohort consisted of 317 pregnancies with T2DM, 92 pregnancies with T1DM, and 1,641 pregnancies without diabetes. The analysis assessed maternal characteristics, glycemic patterns, and neonatal outcomes.

Women with T2DM were older than women with T1DM, with mean ages of 33.4 years and 29.7 years. Body mass index averaged 35.4 kg/m² in T2DM and 26.8 kg/m² in T1DM. Glycemic control was poorer in T1DM throughout pregnancy. Infants of mothers with T1DM had higher rates of large for gestational age at 45.0% and neonatal hypoglycemia at 38.0%.

Perinatal death risk increased significantly in both diabetes groups compared with controls. The odds ratio reached 9.27 in T1DM and 13.5 in T2DM. The risk did not differ significantly between the two diabetes types.
These findings show that pre-existing diabetes mellitus continues to heighten adverse perinatal outcomes across pregnancy groups, regardless of differences in maternal profiles and glycemic control.