Women who live in neighborhoods blighted by dilapidated buildings and other signs of decay are more likely to have premature or low-birth-weight babies, a new study finds.
It's not yet known what physiological thread, or other factor, links urban blight with unhealthy pregnancies, but researchers report in the December issue of Journal of Social, Evolutionary, and Cultural Psychology that the link is strongest among blacks, a group that has 1.5 times the risk of preterm births than whites.
"For African-Americans, they are overrepresented in those areas that have the highest levels of structural deterioration," said study researcher Daniel Kruger, an evolutionary psychologist at the University of Michigan. "So in other words, this could be something that could partially overlie the health disparities that we're seeing."
Kruger and his colleagues focused their study on Flint, Mich., a town that boasted a population of almost 200,000 during the good times of automobile manufacturing in the 1970s. By 2010, the population was barely over 100,000, and boarded-up homes, buildings and factories dotted neighborhoods. The conditions in post-factory Flint were first widely exposed by the 1989 Michael Moore documentary "Roger and Me," which focused on the damage to the city after the GM factory there closed.
Using data from a survey of real estate in Flint and birth records from the Michigan Department of Public Health, the researchers searched for a relationship between the proportion of abandoned buildings and the proportion of premature or low-birth-weight babies. To prevent race from skewing the results, the researchers completed the analysis separately for whites and for blacks.
In both whites and blacks, the researchers found a link between bad neighborhoods and struggling newborns. This link persisted even after the researchers controlled for parental education and insurance status, the socioeconomic data available from birth records.
"Controlling for the socioeconomic indicators, there is a pretty substantial relationship between the concentration of highly dilapidated structures and the local prevalence of low birth-weight and prematurity," Kruger told LiveScience. [10 Healthiest & Safest Cities]
Pregnancy and urban decay
The worse the neighborhood, the tighter the link between dilapidation and low birth-weight and prematurity, Kruger said. Because blacks in the study tended to live in more dilapidated areas, that meant that they were hit hardest by the effect. Decaying neighborhoods explained 30 percent of the variance in rates of low birth-weight births, and 10 percent of the variance in rates of preemie births, among black pregnant women, the researchers found.
"Finding that these harsh environments are associated with prematurity and low birth-weight rate is really important, because it puts kids on a trajectory that could be really difficult to alter," said Bridget Goosby, a sociologist at the University of Nebraska, Lincoln, who researches health disparities but who was not involved in the current study.
The findings are particularly timely given the housing bust and recession, Goosby said.
"Flint, Michigan, is one of those places that experienced a tremendous loss in their manufacturing industry," Goosby told LiveScience. "As we continue to lose industry in this country, we'll probably continue to see these kinds of shifts in neighborhoods."
Evolution and environment
Kruger and his colleagues now plan to do a more in-depth study that includes more information on individual parents' health behaviors and risk factors. They theorize, however, that the link between bad neighborhoods and bad birth outcomes is partly psychological.
Evolutionarily, Kruger said, mothers living in stressful circumstances have been unable to put as many resources into pregnancy and childrearing as when times are flush. In a survival-of-the-fittest world, he said, allocating fewer resources to a developing fetus may have been the only way for the mother to survive — and to potentially bear more offspring in better times. If evolution developed some sort of physical, unconscious method that would translate mothers' anxiety about their environment into less investment in pregnancy, that mechanism would still be hanging around today, Kruger said. Only now, it's more harmful than helpful.
"I think it's a physical mechanism that is deeply rooted in our evolutionary history," he said.
Kruger said that further research would be necessary to investigate the physical mechanisms of this theory. He looked into the possibility of environmental toxins or other physical factors caused by living near abandoned factories playing a role in pregnancy outcomes and found an earlier study indicating no connection between premature births and industrial areas.
"These neighborhoods are also often a mile away from where the factory was, and the factory closed down more than 10 years ago, so I think it's very unlikely that there would be anything in the air or even in the soil," he said.
Whatever the cause, Kruger said, the message is that public health policy needs to have a broader focus than simply telling pregnant women to exercise or eat right. He and his colleagues work with local organizations such as the Genesee County Land Bank to try to help improve local neighborhoods, he said.
"To have a healthy baby, you have to build a healthy environment," Kruger said.