The association between non-metropolitan residence and the risk of poor birth outcome in the United States was examined using the records of 11.06 million singleton births in the United States between 1985 and 1987.

Rates of neonatal and post-neonatal death, low birth weight and late prenatal care among non-metropolitan residents were compared to the rates among metropolitan residents.

The association between residence in a non-metropolitan area and the risk of poor birth outcome was assessed in national and state level regression analyses.

Residence in a non-metropolitan county was not found to be associated with increased risk of low birth weight or neonatal mortality at the national level or in most states, after controlling for several demographic and biological risk factors.

Non-metropolitan residence was associated with greater risk of post-neonatal mortality at the national level.

Non-metropolitan residence was strongly associated with late initiation of prenatal care at both the national level and in a majority of the states.

Residence in non-metropolitan areas does not appear to be associated with higher risk of adverse birth outcome.

Regionalization of perinatal care and other changes in the rural health care system may have mitigated the risk associated with residing in areas relatively isolated from tertiary care. (...)