Severe maternal morbidity and mortality (SMMM) is a major public health concern in the U.S., disproportionately affecting rural communities due to reduced access to obstetric care, long travel distances, and structural inequities. In South Carolina, there is a high maternal mortality and extensive rural obstetric unit closures. Many rural residents travel to urban hospitals for childbirth. However, there is limited information on how this bypassing behavior influences postpartum SMMM risk.
The aim of this study was to assess whether postpartum SMMM risk differs in urban residents, rural residents who give birth locally, and rural residents who bypass local facilities to deliver in nonlocal hospitals, such as urban hospitals, and to evaluate how these risks changed during the COVID-19 public health emergency.
This retrospective population-based cohort study linked to South Carolina’s all-payer inpatient, outpatient, and emergency department hospital data with statewide birth and death certificates from 2018 to 2023. This study included 235,375 deliveries to individuals aged 15 to 50 years. Exclusion criteria included births with missing key demographic or clinical information. Participants were followed for up to one year postpartum. The primary outcome was the time from birth to hospitalization discharge to the first episode of postpartum severe maternal morbidity (SMM) or pregnancy-associated mortality within 365 days. SMM was detected by CDC-defined ICD-10 codes for 20 conditions, excluding transfusion-only cases, and mortality included all-cause deaths within one year postpartum.
Participants were categorized into three exposure groups based on residential and delivery location: urban residents, rural residents delivering at local hospitals, and rural residents delivering at nonlocal hospitals outside their home country. Covariates included maternal age, race/ethnicity, prenatal care adequacy, education, gestational age, obstetric comorbidity index, birth year, delivery mode, hospital obstetric care level, and obstetric workforce characteristics. Statistical analysis used χ² tests for comparing the baseline characteristics, Kaplan-Meier estimates with log-rank tests for evaluating cumulative SMMM incidence, unadjusted rates per 10,000 deliveries, and a multivariable Cox proportional hazards model adjusting for all covariates, with sensitivity analysis performed.
This study found substantial differences in characteristics and outcomes among the three groups. Urban residents accounted for 86% of births, while nearly half of rural births were nonlocal. Rural nonlocal birthing individuals were more likely to be younger, non-Hispanic Black, have lower education, higher comorbidity scores, inadequate prenatal care, and preterm births. They are also more often delivered via cesarean section at higher-level obstetric hospitals staffed by both obstetricians and family physicians. Across the full cohort, 2881 deliveries (122.4 per 10,000) experienced SMMM within one year postpartum with a median time to event of 66 days. Incidence rates were highest in rural nonlocal births (180 per 10,000), followed by urban (118.8 per 10,000) and rural local births (114.7 per 10,000). Cumulative incidence curves showed pronounced disparities after 90 days postpartum.
Rural nonlocal births experienced significantly higher SMMM (adjusted hazard ratio [HR]: 1.18), and rural local births also had a high risk as compared to urban births in fully adjusted models. This pattern was consistent when examining SMM alone. Pregnancy-linked mortality differences were not statistically significant. During the COVID-19 public health emergency, overall risk patterns shifted slightly, but SMMM risk for rural nonlocal births remained elevated. Prenatal care location did not influence postpartum SMMM, and racial and ethnic disparities persisted across all groups.
These findings demonstrate that postpartum SMMM risk is substantially elevated in rural populations and is high in rural residents who bypass local hospitals for childbirth. These findings highlight that rural maternal health disadvantage is not uniform. Travelling long distances for delivery increases risk beyond that associated with rural residence alone. Strategies to mitigate SMMM risk include strengthening rural obstetric care capacity, improving discharge planning, enhancing coordination between urban delivery hospitals and rural postpartum providers, and expanding community-based postpartum support. It is important to ensure timely follow-up and continuous postpartum engagement for rural individuals delivering far from home, which may help to prevent severe maternal complications and reduce maternal health disparities.
Reference: Hung P, Gao H, Liu J, et al. Severe Maternal Morbidity and Mortality After Delivery Hospitalization Among Rural Residents Bypassing Local Care for Urban Hospitals. JAMA Netw Open. 2025;8(11):e2544522. doi:10.1001/jamanetworkopen.2025.44522
