Association Between Preexisting Type 1 and Type 2 Diabetes and Severe Maternal Morbidity

Comorbidities complicate pregnancy and increase the likelihood of severe maternal morbidity, but less is known about the distinct risk of severe maternal morbidity associated with Type 1 and Type 2 pregestational diabetes across the pregnancy and postpartum periods.

This study examined whether individuals with preexisting Type 1 or Type 2 diabetes were more likely to experience severe maternal morbidity than those without diabetes. Multivariable logistic regression was used to analyze insurance claims from the Arkansas All-Payer Claims Database linked to birth records. Severe maternal morbidity and severe maternal morbidity without blood transfusions were evaluated among pregnant individuals with Type 1 diabetes, Type 2 diabetes, or no diabetes. Data were collected from 2017 to 2024 and analyzed in 2025, with a final analytic sample of 176,708 pregnancies.

Individuals with Type 1 diabetes had a 2.2 percentage point higher predicted probability of severe maternal morbidity than those without Type 1 diabetes (p<0.0001) and a 2.0 percentage point higher predicted probability of severe maternal morbidity excluding blood transfusions than those without Type 1 diabetes (p<0.0001). Individuals with Type 2 diabetes had a 1.5 percentage point higher predicted probability of severe maternal morbidity than those without Type 2 diabetes (p<0.0001) and a 1.3 percentage point higher predicted probability of severe maternal morbidity excluding blood transfusions than those without Type 2 diabetes (p<0.0001).

Pregnant individuals with preexisting diabetes have an increased risk of severe maternal morbidity, with Type 1 diabetes conferring a greater risk than Type 2 diabetes. Continued efforts to ensure adherence to clinical standards for comprehensive diabetes management in pregnancy are needed.