MONDAY, Jan. 13, 2003 (HealthDayNews) -- Good neighbors may do more than loan you a cup of sugar, a new Harvard study has found: They might help make your baby bigger and healthier.
Researchers went to more than 300 Chicago neighborhoods and interviewed almost 9,000 people, and they discovered that the cohesiveness of a neighborhood was, at least for white babies, associated with higher birth weights.
"While we know that economic level is associated with birth weight, now we find that there is something about the relationship that people have with each other that can have a positive association with infant birth weight," says Stephen Buka, an associate professor at the Harvard University School of Public Health and lead author of the study.
The effect was only found among white babies, however, he adds, perhaps because of the vast differences between the economic circumstances of the predominantly poorer black neighborhoods versus the predominantly more middle-class white neighborhoods. The average proportion of adults living below the federal poverty line was 31.2 percent in the largely black neighborhoods, compared to 6.2 percent in the white neighborhoods.
"It could be that you have to reach a minimum economic threshold before you achieve the benefits of social cohesion," he says.
Despite this disparity, however, he says, the finding that social cohesion can have a positive impact on infant birth weight gives public policy makers an opportunity to work toward change.
While it is difficult to change the economics of a neighborhood, "the hope is that if we can somehow change the way neighborhoods are that will change the birth weight," he says.
"Not only is that a plausible idea, but a necessary one," says Pragathi Katta, a social policy expert affiliated with George Washington University. "By increasing community cohesiveness, you increase the efficacy of the individual, which is how much the person believes he can act."
The study results appear in the January issue of the American Journal of Epidemiology.
Black babies on average weigh approximately 10 ounces less than white babies at birth, which is a serious health problem, Buka says.
"Low birth weights are known to be associated with learning disabilities and, in adulthood, with an increased risk for health problems."
However, identifying the reasons for the lower birth weight among blacks is difficult, which is what prompted the study.
The researchers studied birth certificates for 95,711 births in 343 neighborhoods -- 29,788 white births and 65,923 black births. They found the difference in birth weights between the two groups to be on average 297 grams, or 10.4 ounces.
They then conducted a household survey of 8,782 adults in the same neighborhoods. They did not interview the women who were pregnant but rather an aggregate number of people in the community, from 15 to 50 people in each neighborhood.
Their survey was designed to assess levels of perceived social support among residents. The questions addressed how much people trusted their neighbors, asking if the neighborhood was close-knit and if people were willing to help each other. They then asked how much interaction they had with their neighbors, whether they did favors for each other or asked questions about child-rearing.
The questions were rated on a scale of one to five, and researchers found that, after adjusting for variables such as maternal risk factors and economic and racial differences, any neighborhood that scored three or above had significantly higher infant birth weights on average than the birth weights of babies in the less cohesive neighborhoods.
Buka surmises in the study that the effect of a more socially cohesive neighborhood may encourage women to stop smoking or seek prenatal care.
Katta praises the study, but says a limitation is that the pregnant women themselves weren't interviewed.
"A woman who's pregnant may or may not feel the stress of these issues," he says.
More information
For causes of low birth weights, you can visit the U.S. Center for the Advancement of Health. The New England Journal of Medicine had an interesting study documenting the low birth weight of black babies.
