Some social and medical correlates of pregnancy outcome.

The separate and joint influence of certain social and medical risks and of early prenatal care on pregnancy outcome was studied in a cohort of 129,739 single live births in upstate New York in 1973. The births were categorized by maternal age, the presence or absence of four putative risk factors, and the provision or nonprovision of early prenatal care. Low birth weight and infant death rates of these categories varied directly with the number of risk factors present. For women exposed to the same risks, however, these rates were significantly lower in those who received prenatal care in the first trimester. But early prenatal care was least common among women at highest risk.