Trends and Differences in Infant Mortality Rates in Rural and Metropolitan Counties in the United States, 2021-2023.

Introduction: This report presents trends in infant mortality among rural, small and medium metropolitan, and large metropolitan counties in the United States from 2014 through 2023, and infant mortality rates by age at death, mother's age, and maternal race and Hispanic origin for combined years 2021-2023.

Methods: Data are from the 2014-2023 National Vital Statistics System linked birth/infant death files. Statistical significance testing for differences in rates are based on a two-tailed z test. References to trends in rates across years were evaluated using the Joinpoint Regression Program.

Key findings: The infant mortality rate declined from 2014 to 2020 for all urbanization levels and then had varying trends across urbanization levels from 2020 to 2023. During 2021-2023, total infant, neonatal, and postneonatal mortality rates were higher in rural and small and medium metropolitan counties compared with large metropolitan counties. Infant mortality rates were higher in rural and small and medium metropolitan counties compared with large metropolitan counties for infants of mothers of all age groups in 2021-2023. Infant mortality rates were higher in rural and small and medium counties compared with large metropolitan counties for infants of most maternal race and Hispanic-origin groups.