Maternal care deserts and risk of maternal morbidity in term pregnancies.

BACKGROUND: Access to maternal healthcare is declining in the United States, with maternal care deserts-counties lacking sufficient obstetric services-expanding. Limited access to obstetric care is associated with increased maternal morbidity and mortality. However, the extent to which living in a maternal care desert is associated with maternal morbidity remains unclear. OBJECTIVE: To evaluate the association between maternal care deserts and adverse maternal outcomes, hypothesizing that counties classified as maternal care deserts experience higher rates of maternal morbidity compared to those with full maternal care access. STUDY DESIGN: This cross-sectional study analyzed singleton, non-anomalous, live births from 37 to 42 weeks gestation using restricted CDC birth certificate data from 2019 to 2021. Births were assigned to the county of maternal residence, and maternal care access was classified at the county level using the 2020 March of Dimes Maternal Care Access Report, categorizing counties as full, moderate, low, or maternal care deserts based on the availability of obstetric hospitals, provider density per 10,000 births, and the percentage of uninsured women. The primary outcome was a composite adverse maternal outcome, including transfusion, unplanned hysterectomy, ruptured uterus, and intensive care unit admission. Secondary outcomes included neonatal adverse events and individual components of the composite score. Mixed-effects logistic regression models estimated associations between maternal care access levels and adverse maternal outcomes, adjusting for individual clinical factors and county-level social vulnerability using the CDC Social Vulnerability Index. RESULTS: Of 3137 U.S. counties, 1099 (35%) were classified as maternal care deserts. Among 9,226,640 included births, 1,108,385 (12.0%) occurred in counties without full maternal care access, including 372,216 (4.0%) in maternal care deserts. Women delivering in maternal care deserts had significantly higher odds of experiencing a composite adverse maternal outcome (adjusted odds ratio [aOR] 1.59; 95% confidence interval [CI] 1.23-2.06) compared to those in counties with full maternal care access. This association was driven by increased rates of transfusion (aOR 2.04; 95% CI 1.45-2.86) and unplanned hysterectomy (aOR 1.24; 95% CI 1.03-1.50). No significant difference was observed in uterine rupture (aOR 0.89; 95% CI 0.72-1.12), whereas patients in maternal care deserts had lower odds of intensive care unit admission (aOR 0.87; 95% CI 0.76-0.99). CONCLUSION: Maternal care deserts are associated with increased maternal morbidity, particularly higher rates of transfusion and unplanned hysterectomy. These findings highlight the urgent need for policies aimed at improving maternal healthcare access in underserved regions to reduce preventable maternal morbidity.