Abortion Restrictiveness and Infant Mortality: An Ecologic Study, 2014-2018.

INTRODUCTION: The U.S. has the highest infant mortality rate among peer countries. Restrictive abortion laws may contribute to poor infant health outcomes. This ecological study investigated the association between county-level infant mortality and state-level abortion access legislation in the U.S. from 2014 to 2018. METHODS: A multivariable regression analysis with the outcome of county-level infant mortality rates, controlling for the primary exposure of state-level abortion laws, and county-level factors, county-level distance to an abortion facility, and state Medicaid expansion status was performed. Incidence rate ratios and 95% CIs were reported. Analyses were conducted in 2022-2023. RESULTS: There were 113,397 infant deaths among 19,559,660 live births (infant mortality rate=5.79 deaths/1,000 live births; 95% CI=5.75, 5.82). Black infant mortality rate (10.69/1,000) was more than twice the White infant mortality rate (4.87/1,000). In the multivariable model, increased infant mortality rates were seen in states with ≥8 restrictive laws, with the most restrictive (11-12 laws) having a 16% increased infant mortality level (adjusted incidence rate ratios=1.162; 95% CI=1.103, 1.224). Increased infant mortality rates were associated with increased county-level Black race individuals (adjusted incidence rate ratios=1.031; 95% CI=1.026, 1.037), high school education (adjusted incidence rate ratios=1.018; 95% CI=1.008, 1.029), maternal smoking (adjusted incidence rate ratios=1.025; 95% CI=1.018, 1.033), and inadequate prenatal care (adjusted incidence rate ratios=1.045; 95% CI=1.036, 1.055). CONCLUSIONS: State-level abortion law restrictiveness is associated with higher county-level infant mortality rates. The Supreme Court decision on Dobbs versus Jackson and changes in state laws limiting abortion may affect future infant mortality.