Multilevel Intersectional Social Drivers of Health and Nulliparous Term, Singleton, Vertex Cesarean Delivery

OBJECTIVE: To examine the intersectionality of three frequently measured neighborhood social determinants during pregnancy—socioeconomic disadvantage, food access, and walkability—and their collective association with nulliparous term, singleton, vertex (NTSV) cesarean delivery. METHODS: This was a secondary analysis of data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be observational cohort. Home addresses in the first trimester were geocoded at the census-tract level to define three adverse neighborhood measures: 1) socioeconomic disadvantage by the Area Deprivation Index (in tertiles), 2) low food access by the U.S. Department of Agriculture Food Access Research Atlas (yes/no), and 3) low walkability by the Environmental Protection Agency National Walkability Score (yes/no). The exposure was the number of neighborhood adverse social determinants and was assessed by number (0, 1, 2 or more) and specific combinations. The outcome was NTSV cesarean delivery. Multivariable modified Poisson regression with robust error variance was used. We secondarily assessed the distribution of clinical indications for cesarean delivery and whether associations between neighborhood social determinants and cesarean delivery varied by self-reported race and ethnicity. RESULTS: Among 8,010 nulliparous individuals with NTSV deliveries, 27.3% lived in a neighborhood in the top tertile of socioeconomic disadvantage, 24.5% with low food access, and 66.4% with low walkability. The risk of NTSV cesarean delivery was higher only among individuals living in neighborhoods with low walkability (adjusted relative risk [RR] 1.17, 95% CI, 1.06–1.28). Individuals exposed to one (adjusted RR 1.14, 95% CI, 1.01–1.27) or two or more (adjusted RR 1.19, 95% CI, 1.06–1.34) compared with no adverse neighborhood social determinants had a higher risk of cesarean delivery. Individuals living in neighborhoods with low walkability and high socioeconomic disadvantage (adjusted RR 1.21, 95% CI, 1.03–1.41) or low walkability and low food access (adjusted RR 1.20, 95% CI, 1.05–1.37) had a higher risk of cesarean delivery. The frequency of all three adverse neighborhood social determinants was higher for non-Hispanic Black and Hispanic individuals compared with non-Hispanic White individuals ( P <.05), but the above association between neighborhood social determinants and cesarean delivery did not vary by self-reported race and ethnicity (adjusted interaction P =.6). CONCLUSION: In a prospective U.S. cohort, living in a neighborhood with low walkability, alone and in combination with socioeconomic disadvantage and food access, was associated with an increased risk of NTSV cesarean delivery.