WASHINGTON — In the long list of health disparities that vex and disproportionately affect the lives of African-Americans - diabetes, cancer and obesity among them - one of the earliest and, it turns out, most significant, may be just when a black child is born.
A pair of Emory University studies released this year have connected the large share of African-American children born before term with the biologically detectable effects of stress created in women's bodies after decades of dealing with American racism. The studies' findings don't end there.
Racism, and its ability to increase the odds that a pregnant mother will deliver her child early, can kill. There is also evidence that racism can alter the capacity for a child to learn and distorts lives in ways that can reproduce inequality, poverty and long-term disadvantage, the studies found.
"Racism is an incredibly powerful force," said Elizabeth Corwin, dean of research at Emory University's Woodruff School of Nursing,
In 2012, 11.5 percent of American children were born preterm, the medical community's shorthand for a child who spends 38 weeks or less in their mother's womb. That figure translates to about 15 million premature infants last year. Despite a range of medical advances, children born early often struggle to survive. Once they arrive early, preterm babies are more likely to face short- and long-term health challenges that can translate into difficulty learning. That much is known, and after decades of research, well-established.
Every week in the womb matters.
Children born too soon are more than a third more likely than others to die within their first year of life or suffer with cerebral palsy, blindness, breathing and learning challenges that can last a lifetime. Preterm birth is the second-leading cause of infant mortality, a tidy term for the tragic death of a child before the first birthday. In 2010, the last year for which we have statistics, more than 7,000 of those who died were African-American babies.
Preterm birth is such a threat to human health that in October, the American College of Obstetricians and Gynecologists moved the goal post for expectant mothers and their health care providers. Babies must now remain in their mother's wombs for 39 weeks or more to be considered full-term.
But drill down on America's premature birth problem - the worst in the industrialized world - and the real problem becomes clear. About 10.5 percent of white children were born before 37 weeks gestation in 2012, according to the March of Dimes' 2013 Premature Birth Report Card. But about 11.7 percent of Latino children, 13.6 percent of Native American babies, 10.3 percent of Asian kids and a tragic 16.8 percent of black infants arrived too soon.
The tenacity of those gaps has spawned decades of research, said Diane Rowley, a professor at the University of North Carolina's Gillings School of Global Public Health.
Public health researchers and doctors spent years attributing the disproportionate numbers of preterm minority children to elevated poverty, gaps in insurance coverage and limited access to quality prenatal care, said Rowley. But over time, the studies revealed something more complex.
Black women up and down the income and education ladder disproportionately deliver their children too early.
"The research was at first just suggesting, but it's well-established today, something about living in the United States, something beyond poverty or health insurance coverage and health care access is helping to shape pregnancy outcomes," Rowley said. "And that something is racism."
In short, the research concludes, racism - the psychological and physical strain that it causes - is prompting some children to be born too soon. Poverty and health care access matter, but so, too, do social conditions.
Long-time public health specialists like Rowley know that racism - whether it exists, when and how it is perceived and how it shapes lives - is not only controversial; it's difficult to measure.
Enter the researchers at Emory University.
In September, Corwin, the dean of research at Emory's School of Nursing, and a team of researchers closely tracked the pregnancies of more than 100 women during the last three months of their pregnancies. They found that women of all races and ethnicities who are poor during their pregnancies are more likely to suffer from chronic stress, a biologically detectable condition. The same is also true, she said, of middle-class black women and second- and later-generation Latinas.
Chronic stress, the team extrapolated, is the reason some 30,000 more African-American babies are born prematurely each year than any other group.
The big revelations coming out of Emory didn't stop there. Preterm birth is long understood to have a potential impact on a child's cognition and language-learning skills. But Michael Kramer, an epidemiologist at Emory's School of Public Health, examined the birth and school records of thousands of Georgians born between 1998 and 2003. When these children took state academic assessment tests in first grade, those born prematurely were more likely to fail.
The more premature the birth, the worse the child performed. Only 13 percent of the babies born on time or less than three weeks early fell short on first-grade tests, compared to a third of the children born 13 to 20 weeks prematurely.
"What we found explains some, but by no means all, of the academic achievement gap," Kramer said. "There are real differences we can make in education by investing in what happens long before children reach school."
Kramer's findings also suggest that since poor minority families often concentrate in sections of a city and therefore send their children to the same set of the nation's increasingly segregated (by both race and class) schools, children struggling to learn due to a preterm birth aren't evenly disbursed. Some schools are likely serving large numbers while others, in wealthier communities and those serving mostly white students, may be serving few to none.
"I think that our research may be shocking to a lot of people, but I hope not dispiriting," said Corwin with Emory. "We have some clue what may be causing disproportionate rates of preterm births in some segments of the population, and we know that we can try to intervene early. The question is really whether that is something that we are prepared as a country to do."