The association between maternal care access and term stillbirth at the US county level.

Introduction: Access to comprehensive maternal care is associated with a reduction in stillbirth rates. Given the decreasing access to maternal care across the United States, the aim of this study was to investigate the association of county-level maternal care access in the United States with stillbirth rate at term. Methods: This is a cross-sectional study using Centers for Disease Control and Prevention (CDC) Vital Statistics birth certificate data from 2016 to 2019. All non-anomalous, singleton births of ≥37 weeks' gestation were included. Maternal care access level was defined by the 2020 March of Dimes Maternal Care Access Report county data that classified maternal care access as full, moderate, low, or desert, which they based on the availability of hospitals providing obstetric care, the number of obstetric providers per 10,000 births, and the percent of uninsured women. The primary outcome was stillbirth at term (≥37 weeks' gestational age). Mixed-effects multivariable models were used and adjusted for clinical, demographic, and county-level factors, including access to community resources as defined by the CDC's Social Vulnerability Index (SVI). Results: A total of 3138 counties were included in this analysis with 1100 (35.1%) of those counties located in maternal care deserts. Out of 13,304,743 births, term stillbirth occurred in 16,402 deliveries (0.12%) with 13.2% of these stillbirths occurring in counties without full access to maternal care. In unadjusted models, there were increased odds of stillbirth in maternal care deserts (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.04-1.22) when compared to full maternal care access. However, this was not statistically significant after adjusting for individual and county-level factors (adjusted odds ratio [aOR], 0.98; 95% CI, 0.89-1.09). Conclusion: More than one third of US counties are in maternal care deserts and 13% of term stillbirths occur in areas without full access to maternal care. Although the association between county-level maternal care access and term stillbirth was attenuated after adjustment for individual and contextual factors, these findings highlight important geographic inequities in care availability. Continued work using more granular, patient-level and facility-level measures of access, including care modalities, care quality, and actual service utilization, is needed to better characterize the pathways through which declining obstetric care infrastructure may influence stillbirth risk.