Premature birth, particularly the very early premature births, are the most significant factor in the high infant mortality rates in the United States, particularly in urban areas of this country.
But a new study by researchers from the National Institutes of Health and elsewhere found that even babies born nearly to term – those at 37 and 38 weeks gestation, as opposed to the full 40 weeks – were at significantly higher risk of dying in their first year of life. Babies are not considered premature if they are born after 36 weeks of gestation. The study terms those who are 37 and 38 weeks “early-term” births.
“Early-term births are associated with higher neonatal, postneonatal and infant mortality rates compared with full-term births,” the researcher concluded in their study published in the June issue of the journal Obstetrics and Gynecology.
Moreover, the researchers found significantly higher death rates among blacks than whites in these babies.
“At both early- and full-term gestations, neonatal mortality rates for blacks are 40 percent higher than for whites and postneonatal mortality rates 80 percent higher,” the researchers wrote.
The researchers analyzed data from 46.3 million live births in the U.S. linking that data to infant death data from 1995 to 2006.
“These data demonstrate that ‘term’ pregnancy is not a period of uniform risk with early-term deliveries (37 and 37 weeks of gestation) experiencing higher … infant mortality rates than full-term deliveries (39 and 40 weeks of gestation),” the researchers wrote.
“Although there have been improvements in overall neonatal, postneonatal and infant mortality rates across the term period n the past decade, the unacceptable disparity in infant mortality remains for non-Hispanic blacks and must be targeted by intervention to decrease the mortality rate for this high risk group.”