A report by the National Center for Health Statistics, part of the Centers for Disease Control and Prevention, said the three leading causes of infant death -- neonatal mortality rate involved infants less than 28 days old -- were congenital malformations, low birth weight and Sudden Infant Death Syndrome. They accounted for 46 percent of all infant deaths.
The U.S. preterm birth rate peaked in 2006 at 12.8 percent and dropped to 12 percent in 2010, the report said.
Nearly a half million U.S. babies are born prematurely and those who survive face an increased risk of lifelong health challenges -- including cerebral palsy, breathing problems, intellectual disabilities and other health and developmental problems -- the March of Dimes said.
"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 report said. "Infant mortality was higher for male infants and infants born preterm or at low birth weight. Infant mortality rates were also higher for those infants who were born in multiple
deliveries or to mothers who were unmarried."
In a 2012 worldwide ranking by the CIA World Factbook -- a public of the U.S. Central Intelligence Agency -- the U.S. infant mortality rate ranked 49th, ahead of Croatia at No. 50, while Monaco ranked No. 1, with an infant mortality rate of 1.80 per 1,000 live births.