Geographic and Racial Disparities in Maternal and Infant Mortality Rates Across U.S. States: A Population-Based Analysis.

Background Maternal and infant mortality remain critical indicators of population health in the United States, with persistent geographic and racial/ethnic disparities. Although these outcomes are often examined separately, less attention has been given to whether jurisdictions with higher infant mortality also experience higher maternal mortality. This ecological, jurisdiction-level study evaluated recent patterns in maternal and infant mortality across the 50 U.S. states and the District of Columbia, examined geographic and racial/ethnic disparities, and assessed the association between infant mortality rate (IMR) and maternal mortality rate (MMR). Methods This population-based analysis used publicly available Centers for Disease Control and Prevention (CDC) WONDER data. The primary jurisdiction-level analysis used pooled 2020-2024 infant and maternal mortality data to assess overall geographic patterns and the association between IMR and MMR. Secondary race/ethnicity-specific analyses used pooled 2020-2023 data because CDC Linked Birth/Infant Death Records were available through 2023. Race/ethnicity categories included non-Hispanic White, non-Hispanic Black, Hispanic, non-Hispanic Asian, non-Hispanic Native Hawaiian or Other Pacific Islander (NHOPI), and non-Hispanic American Indian and Alaska Native (AIAN). IMR was calculated per 1,000 live births, and MMR per 100,000 live births. Pearson correlation and analysis of variance (ANOVA) were used. Results Using pooled 2020-2024 data, overall IMR ranged from 3.43 to 9.04 deaths per 1,000 live births, with the lowest rates in Massachusetts, New Jersey, and New Hampshire and the highest in Mississippi, Arkansas, and Louisiana. Overall, MMR ranged from 0.00 to 41.76 deaths per 100,000 live births; zero and low-count values were interpreted cautiously because maternal mortality is rare and jurisdiction-level estimates may be unstable. The lowest reported MMRs were in Vermont, California, and Utah, and the highest were in Tennessee, Louisiana, and Mississippi. The South had the highest mean IMR and MMR, while the Northeast had the lowest. In secondary 2020-2023 race/ethnicity-specific analyses, disparities persisted across expanded racial/ethnic categories, although jurisdiction-level estimates for smaller groups were limited by low counts and data suppression. Black populations had higher IMR and MMR than White and Hispanic populations. AIAN and NHOPI populations also had elevated aggregate infant mortality, and AIAN populations had elevated aggregate maternal mortality. Male infants had higher mortality than female infants. Overall, IMR and MMR were positively correlated across jurisdictions. Conclusions Geographic and racial/ethnic disparities in maternal and infant mortality remain substantial in recent U.S. data, with the greatest burden concentrated in Southern jurisdictions and among Black populations. Elevated rates were also observed among AIAN and NHOPI populations, where data were available. The jurisdiction-level association between IMR and MMR suggests that these outcomes may share overlapping population-level determinants, although causal or individual-level inferences cannot be made from this ecological analysis. Future studies should examine structural, socioeconomic, and healthcare-system factors that may explain the parallel distribution of maternal and infant mortality across jurisdictions.