Study shows babies of African ancestry more likely to be born prematurely
Low birth weights are more prevalent among Brazilians with African ancestry and may be attributed to less use of prenatal care facilities and where those ethnic groups live, according to a new study.
The study from researchers at the University of Iowa and health analysts in South America also suggests that infants of African ancestry, alone or mixed, were more likely to be born prematurely than those born of European-only stock. The findings could help policymakers decide how best to bridge the difference in infant health among non-European-ancestry races in South America's largest and most populous country.
"This suggests that where you live in Brazil makes a difference, and where you live varies to a certain extent by what your ethnic ancestry is," says George Wehby, associate professor in the UI College of Public Health and the corresponding author of the study published this month in the American Journal of Public Health. "There is some form of segregation and that's what contributing to low birth weight among these racial groups."
The researchers examined 8,949 infants born in select hospitals in 15 cities in seven states, between 1995 and 2009. The infants were grouped in four ethnic categories: those of African ancestry; those of African and European ancestry; those of African and other (non-European) ancestry; and those of European-only ancestry. The team focused on whether infants were born prematurely and whether their birth weight was low (less than 2,500 grams or 6 pounds).
The group found that 12 percent of infants with African ancestry had low birth weights, compared to 8 percent of infants of European ancestry. The rate was nearly a percentage point higher for mixed-race infants (mixed African and European ancestry).
While the percentage difference may not seem pronounced, "it means that out of 100 children, there are four more children (of African ancestry) born at a low birth weight," Wehby says. Viewed another way, children of African origin are one-and-a half times more likely to be born at a low birth weight than their European-only counterparts, Wehby notes.
Preterm birth rates for infants of African or mixed-race ancestry were nearly three to five percentage points higher than the rate for babies with European-only ancestry, the study found.
Previous research has indicated that differences in birth weight and preterm birth rates may be magnified as the child ages, and reflected in overall health, productivity, and earning power.