Trends in Pregestational and Gestational Diabetes Mellitus and Associations With Severe Maternal Morbidity in U.S. Delivery Hospitalizations, 2016–2022

OBJECTIVE: To describe trends in the prevalence of gestational diabetes mellitus (GDM), pregestational diabetes mellitus (type 1 and type 2), and severe maternal morbidity (SMM) in the U.S., and to examine associations between diabetes status and type with SMM. RESEARCH DESIGN AND METHODS: This retrospective study used 2016-2022 data from the Healthcare Cost and Utilization Project National Inpatient Sample. Delivery hospitalizations among women ages 12-55 years were identified. Modified Poisson regression models were used to estimate relative risks (RRs) for overall and nontransfusion SMM, adjusting for sociodemographic and clinical characteristics. RESULTS: Among 25,138,817 delivery hospitalizations, the prevalence of GDM increased from 7.1 to 9.5 per 100 deliveries, pregestational diabetes mellitus type 2 increased from 0.8 to 1.1 per 100 deliveries, and pregestational diabetes mellitus type 1 remained stable at 0.3 per 100 deliveries from 2016 to 2022. Overall SMM increased from 160.0 to 220.3 per 10,000 deliveries; nontransfusion SMM increased from 72.0 to 93.0 per 10,000 deliveries. In sociodemographic-adjusted models, compared with women without diabetes, type 1 diabetes was associated with the highest risk of nontransfusion SMM (RR 4.94; 95% CI 4.55-5.35), followed by type 2 diabetes (RR 2.58; 95% CI 2.43-2.74) and GDM (RR 1.12; 95% CI 1.08-1.15). CONCLUSIONS: From 2016 to 2022, GDM and pregestational diabetes mellitus type 2 rose in parallel with increasing SMM. While GDM was the most prevalent, pregestational diabetes mellitus, particularly type 1, was associated with a higher risk of SMM. The increased risk for SMM associated with all forms of diabetes in pregnancy highlights the importance of cardiometabolic risk management and the need for comprehensive, multidisciplinary care during pregnancy and delivery.