MONDAY, Oct. 2, 2006 (HealthDay News) -- Being born too early may be a bigger threat to babies' health than previously realized.
A new study from the U.S. Centers for Disease Control and Prevention suggests that one-third of all infant deaths in 2002 were linked to prematurity, defined as birth before 37 weeks' gestation.
That's double the risk experts had so far estimated.
"We have long known that babies born too soon face many challenges -- even death. But this research confirms the urgent role preventing preterm birth can play in improving infant mortality in the United States," Joann Petrini, director of the March of Dimes' Perinatal Data Center, said in a prepared statement.
The findings were published in the October issue of the journal Pediatrics.
The CDC study came after a puzzling discrepancy in statistics for infant mortality in the United States. In 2002, the National Center for Health Statistics estimated that 17 percent of infant deaths were linked to premature birth. However, the same statistics showed that two-thirds of babies who died that year had been born prematurely.
This difference suggested to the CDC researchers that the official reporting system may not indicate the true impact of prematurity in infant deaths.
So their analysis used a different methodology. Looking at infant deaths, they not only included prematurity but also other conditions -- such as respiratory distress syndrome -- that often occur in "preemie" babies.
Using this approach, the CDC team concluded that prematurity was the underlying cause in 34.3 percent of infant deaths in 2002. More than 95 percent of those deaths involved "very preterm" infants born at less than 32 weeks' gestation, the CDC team added.
The new analysis could mean that prematurity now supplants birth defects as the leading cause of infant deaths in the United States, according to the researchers.
Overall, U.S. infant mortality has declined steadily since 1995, except between 2001-2002 -- the first rise since 1958. More than 500,000 U.S. babies are born too soon each year, and experts say the rate for preterm births has jumped more than 30 percent since 1981.
Besides raising infant-mortality risks, preterm birth also raises a child's risk for mental retardation, chronic lung disease, vision/hearing problems, and other developmental problems.
Research is yielding new hope for preemie babies, however. In September, a team at the University of Cincinnati Medical Center discovered a genetic pathway crucial to controlling respiratory distress syndrome in newborns at risk.
And earlier this summer, an Australian team announced that repeat doses of corticosteroids, given to expectant mothers at high risk for premature delivery, might help protect their newborns against lung ailments and other illnesses.
More information
There's more on premature birth at the March of Dimes.
