Severe Maternal Morbidity and Mortality After Delivery Hospitalization Among Rural Residents Bypassing Local Care for Urban Hospitals.

Importance: Rural residents experience higher severe maternal morbidity and mortality (SMMM) and limited local hospital obstetric supply. However, data on postpartum SMMM among these rural residents bypassing local communities for childbirth are limited. Objective: To estimate postpartum SMMM among urban, rural nonlocal, and rural local births. Design, Setting, and Participants: This retrospective population-based cohort study identified all childbirth deliveries and hospitalization discharges from January 1, 2018, to December 31, 2022, in South Carolina and followed-up to 1-year postpartum using data from all-payer hospital inpatient, outpatient, and emergency department visits linking to vital records for birth and death certificates information. Data were analyzed from March to September 2025. Exposure: Urban residency, rural residency with nonlocal birth (ie, urban hospital deliveries), and rural residency with local birth (deliveries at in-county or adjacent rural hospitals), classified using the 2023 Rural-Urban Continuum Codes definitions (1-3, urban; 4-9, rural). Main Outcome and Measures: The primary outcomes of postpartum SMMM-severe maternal morbidity (SMM) and/or pregnancy-associated mortality-were identified using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis and procedure codes and death certificates, respectively. Cox proportional hazards models compared cumulative incidence and timing of postpartum SMMM across exposure groups. Results: Of 235 375 deliveries to 197 216 women (mean [SD] maternal age, 28.3 [5.8] years), 203 325 (86.4%) were to urban residents, 15 053 (6.4%) were to rural residents bypassing local birth sites for urban hospitals, and 16 997 (7.2%) were to rural residents delivering locally, yielding a 47.0% bypassing rate for rural residents. SMMM was highest among rural nonlocal deliveries (180.0 per 10 000 births), followed by similar rates for urban (118.8 per 10 000 births) and rural local deliveries (114.7 per 10 000 births). Adjustment for maternal sociodemographic characteristics, clinical factors, and hospital characteristics still showed higher SMMM risk for rural nonlocal vs urban deliveries (adjusted hazard ratio, 1.18; 95% CI, 1.04-1.33), while the risk associated with rural local vs urban delivery was not significantly different. Conclusions and Relevance: In this cohort study of 2018 to 2022 childbirth deliveries in South Carolina, rural local deliveries had SMMM risks comparable to urban births, but rural nonlocal deliveries were associated with increased risk. These findings suggest that targeted interventions (eg, strengthening rural obstetric care supply, childbirth discharge planning, postpartum care coordination, and timely follow-up) may help mitigate these disparities for rural nonlocal births.