Associations of the Neighborhood Built Environment with Physical Activity across Pregnancy

Background: Several features of the neighborhood built environment have been shown to promote leisure-time physical activity (PA) in the general population, but few studies have examined its impact on PA during pregnancy. Methods: Data were extracted from 8362 Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort participants (2010-2013). Residential address information was linked to 3 built environment characteristics: Number of gyms and recreation areas within a 3-km radius of residence and census block level walkability. Self-reported leisure-time PA was measured in each trimester and dichotomized as meeting PA guidelines or not. Relative risks for cross-sectional associations between neighborhood characteristics and meeting PA guidelines were estimated using Poisson regression. Results: More gyms and recreation areas were each associated with a greater chance of meeting PA guidelines in models adjusted for sociodemographic characteristics and preexisting conditions. Associations were strongest in the third trimester where each doubling in counts of gyms and recreation areas was associated with 10% (95% confidence interval, 1.07-1.13) and 8% (95% confidence interval, 1.03-1.12), respectively, greater likelihood of meeting PA guidelines. Associations were similar though weaker for walkability. Conclusions: Results from a large, multisite cohort suggest that these built environment characteristics have similar PA-promoting benefits in pregnant women as seen in more general populations.