'Hypersegregation' May Contribute to Preterm Births Among Black Women

New research suggests that one reason behind racial disparities in preterm birth may have a lot to do with where the mother lives. Written by Northeastern University professor Theresa Osypuk, the study found that regional hypersegregation (residential racial segregation across four or more dimensions*) may contribute to the higher rate of preterm births among black women. Prior research has shown that infants born to Black women in the U.S. are 50% more likely to be preterm than infants born to White women, although the causes remain poorly understood.

The paper, titled “Are Racial Disparities in Preterm Birth Larger in Hypersegregated Areas?,” also found that older black women living in areas of the country with very high levels of neighborhood segregation experience even higher risk of preterm birth than black mothers in less segregated areas. The study appeared in the latest issue of the American Journal of Epidemiology.

Dr. Osypuk analyzed all the White and Black mothers giving birth in 237 metropolitan areas, including Boston – almost two million infants – to estimate the odds of preterm birth by hypersegregation, race and age. Lead author, Dr. Osypuk and her corresponding author, Dolores Acevedo-Garcia also found that regional hypersegregation may also contribute to the larger racial disparity in preterm births between black and white infants.

”The complexity of residential segregation and its impact on preterm births and related health outcomes has been overlooked by health literature,” said Dr. Osypuk, Assistant Professor in Northeastern’s Bouve College of Health Sciences. “We believe that the association between residential segregation and higher risk of preterm birth is related to the neighborhood environments in which black women live, including neighborhoods characterized by high levels of poverty, violent crime, and worse housing stock.”

The authors found that the association between higher rates of preterm births and hypersegragated areas was more pronounced at higher maternal ages. The racial disparity was also larger at higher ages. For example, an infant born to a black woman over 40 years of age had a 2-times higher risk of preterm birth than a white infant of the same age in non-segregated regions, but this disparity in risk was 3 times higher in hypersegregated areas.

“This finding suggests that age-related preterm birth patterns may be related to stressors associated with residential segregation and neighborhood inequalities facing Black women, which accumulate with age. And these are stressors that white women just may not experience,” added Dr. Osypuk.

“Because of high levels of racial segregation, most black and white women in the US live in entirely separate neighborhoods, and these neighborhoods differ markedly in their quality. In fact, some of our prior work finds that the racial disparity in neighborhood quality is largest in highly segregated areas.”