MONDAY, May 23, 2011 (HealthDay News) -- Newborns delivered only a week or two early still face a significantly higher risk of death, a new study finds.
Researchers at the March of Dimes, the U.S. National Institutes of Health and the U.S. Food and Drug Administration found that the odds for death more than double for newborns born at 37 weeks versus babies born at 40 weeks of pregnancy.
"There is the perception that babies born between 37 and 41 weeks of pregnancy are all born healthy. But this study confirms that even babies born just a week or two early have an increased risk of death," Dr. Alan R. Fleischman, senior vice president and medical director at the March of Dimes, said in a new release from the group. "It is clear, that regardless of race or ethnicity, every additional week of pregnancy is critical to a baby's health."
The study, published in the June issue of Obstetrics & Gynecology, looked at U.S. data on infant mortality from 1995 to 2006. It found that 1.9 per every 1,000 newborns died among those babies delivered at 40 weeks, but that number climbed to 3.9 per 1,000 among babies born at 37 weeks of pregnancy.
This trend was observed across all races and ethnicities but was most pronounced among black infants, the researchers said.
"Although infant mortality rates overall improved in the past decade, rates for non-Hispanic black babies born at 37 or 38 weeks of pregnancy remain unacceptably higher than other racial and ethnic groups," Dr. Uma Reddy, of the National Institute of Child Health and Human Development, said in the same news release. "Our results indicate that intervention programs are needed for this high-risk group, as is additional research to understand why non-Hispanic black infants are less likely than other groups to live to celebrate their first birthday."
Preterm birth is defined as birth occurring at less than 37 weeks of gestation, the March of Dimes noted. However, stopping short of 40 weeks is still less than ideal, the group added. While delivery earlier than 39 to 40 weeks is sometimes medically necessary, the March of Dimes stresses that early elective delivery can be harmful to a baby "and should never be scheduled before 39 or 40 weeks of pregnancy."
There's more on premature birth at the U.S. Centers for Disease Control and Prevention.