Factors Associated With the Transition to Nonprone Sleep Positions of Infants in the United States

Abstract
SUDDEN INFANT DEATH syndrome (SIDS) is the leading cause of postneonatal infant mortality (deaths between 1 month and 1 year of age) in the United States. In 1992, 4891 infants died with this diagnosis, corresponding to a rate of 1.20 deaths per 1000 live births.1 The rate of SIDS in the United States changed little during the decade prior to 1992, despite significant drops in overall infant mortality. Studies in the United States have identified factors associated with 2-fold to 4-fold increased risk for SIDS, including preterm birth, low birth weight, young maternal age, high parity, late or no prenatal care, smoking and substance abuse during pregnancy,2 and postnatal exposure to environmental cigarette smoke.3 Most of these factors are also associated with other causes of infant mortality4 and have proven to be difficult to modify in populations at risk.5,6