Infant mortality statistics from the 2009 period linked birth/infant death data set.

OBJECTIVES This report presents 2009 period infant mortality statistics from the linked birth/infant death data set (linked file) by 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 infant mortality rate in the United States in 2009 was 6.39 infant deaths per 1,000 live births, 3% lower than the rate of 6.61 in 2008. The number of infant deaths was 28,075 in 2008 and 26,408 in 2009, a decline of 1,667 infant deaths. Infant mortality rates ranged from 4.40 per 1,000 live births for Asian or Pacific Islander mothers to 12.40 for non-Hispanic black mothers. 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 2008 to 2009, the neonatal mortality rate (under age 28 days) declined 3% to 4.18 neonatal deaths per 1,000 live births, while the postneonatal mortality rate (aged 28 days to under 1 year) declined 5% to 2.21. Preterm and low birthweight infants had the highest infant mortality rates and contributed greatly to overall U.S. infant mortality. The three leading causes of infant death--congenital malformations, low birthweight, and sudden infant death syndrome--accounted for 46% of all infant deaths. In 2009, 35.4% of infant deaths were "preterm-related."