Infant mortality statistics from the 2008 period linked birth/infant death data set.

OBJECTIVES: This report presents 2008 period infant mortality statistics from the linked birth/infant death data set (linked file) by a variety of maternal and infant characteristics. The linked file differs from the mortality file, which is based entirely on death certificate data.
METHODS: Descriptive tabulations of data are presented and interpreted.
RESULTS: The U.S. infant mortality rate was 6.61 infant deaths per 1,000 live births in 2008, 2 percent lower than the rate of 6.75 in 2007. Infant mortality rates ranged from 4.51 per 1,000 live births for Asian or Pacific Islander mothers to 12.67 for non-Hispanic black mothers. The rate for non-Hispanic black women declined 5 percent from 2007 to 2008. Infant mortality was higher for male infants and infants born preterm or at low birthweight. Infant mortality rates were also higher for those infants who were born in multiple deliveries, to mothers who were unmarried, and for those whose mothers were born in the 50 states or the District of Columbia. From 2007 to 2008, the neonatal mortality rate (under age 28 days) declined by 3 percent to 4.29 neonatal deaths per 1,000 live births, while the postneonatal mortality rate (aged 28 days to under 1 year) remained essentially unchanged (2.32). Preterm and low birthweight infants had the highest infant mortality rates and contributed greatly to the overall U.S. infant mortality. The three leading causes of infant death--congenital malformations, low birthweight, and sudden infant death syndrome--accounted for 46 percent of all infant deaths. In 2008, 35.4 percent of infant deaths were "preterm-related."