The rate of preterm delivery was linked to perceptions of neighborhood environmental characteristics among Detroit-area black women with no more than a high school education who participated in a study conducted in 2009–2011.1 It was positively associated with perceptions of social disorder in the neighborhood, and was negatively associated with perceptions of the neighborhood's walkability, safety and availability of healthy food. For women with more than 12 years of education, no such associations were apparent.
The retrospective cohort study, which was designed to examine how preterm delivery is associated with racism, recruited black women aged 18 and older who delivered singleton infants at a hospital in Oakland County, Michigan. Investigators interviewed 1,411 women during their postpartum hospital stay and obtained information about their medical histories from their medical records. They defined a preterm delivery as one that occurred before 37 completed weeks of gestation, as estimated on the basis of an early ultrasound (available for 692 women), the date of the last menstrual period (465) or, lacking these, a variety of alternative methods. Participants reported on characteristics of the neighborhoods in which they lived, using scales that produced measures of social cohesion and trust (e.g., whether neighbors help each other out and get along), the availability of healthy food (fresh produce and low-fat products), walkability (e.g., whether it is easy and pleasant to walk around the neighborhood), social disorder (e.g., the extent to which litter, graffiti and public drinking are problems) and safety.
In all, 231 women in the sample had preterm deliveries, and 1,179 delivered at term. In both groups, slightly more than half of women were in their 20s, were married or cohabiting, and had an annual income of less than $35,000; three in 10 had at most a high school education. The sample was about evenly divided between Detroit residents and suburban women; close to six in 10 women in both the preterm and the term delivery groups had lived in their current neighborhood for no more than 24 months.
Mean scores on the perceived neighborhood environment measures were similar for women who had preterm deliveries and those who gave birth at term: for social cohesion and trust, 24 (range, 7–35); for availability of healthy food, 7 (2–10); for walkability, 23 (6–30); for social disorder, 12 (8–24); and for safety, 21 (6–30). (For social disorder, the higher the score, the worse the perceived environment; for all other scales, the higher the score, the better the perceived environment.)
The investigators conducted log-binomial regression analyses and found no significant relationships between women's demographic characteristics and their rate of preterm delivery. They also found no associations between the rate of preterm delivery and any of the neighborhood environment measures for the sample overall. However, analyses stratified by women's level of education revealed that for those who had not gone beyond high school, the rate was associated with four of the five neighborhood environment measures: It declined with increasing perceptions of neighborhood walkability, safety and healthy food availability (prevalence ratios, 0.7–0.8), and increased with increasing perceptions of disorder (1.5).
Given that exposure to stress is a known risk factor for preterm delivery, the investigators say, "it is…not surprising" that preterm delivery rates were associated with perceptions of the neighborhood environment only among women with no postsecondary education. At the same time, the researchers recognize a number of limitations of their study. For example, the findings may not be widely generalizable, the data did not account for women's changes in residence over time and the models stratified by educational level did not control for income or marital status. Achieving a better understanding of the preterm delivery rates of women with low education, the investigators conclude, requires "a deeper understanding of the complex and dynamic relationships between individual and environmental factors."
—D. Hollander
REFERENCE
1. Sealy-Jefferson S et al., Perceived physical and social residential environment and preterm delivery in African-American women, American Journal of Epidemiology, 2015, 182(6):485–493, doi: 10.1093/aje.kwv106.