RESUMO
BACKGROUND: Prior studies have reported decreases in the preterm delivery incidence during the COVID-19 pandemic. However, the findings are inconsistent. Given the wide disparities in the pandemic's impact across communities, neighborhood deprivation may explain the observed variation in the relationship between the COVID-19 pandemic and preterm delivery. OBJECTIVE: To characterize the changes in the incidence of preterm delivery during the COVID-19 pandemic with attention to the effect modification introduced by neighborhood hardship. STUDY DESIGN: This retrospective cohort study included all the pregnant patients who delivered at an urban tertiary care hospital during the pandemic (April-November 2020) or before the pandemic (April-November 2019). We compared the incidence of preterm delivery, spontaneous preterm delivery, and medically indicated preterm delivery before 37 weeks' gestation across epochs. Planned analyses stratified the cohorts by neighborhood deprivation metrics defined by the residential zip code; the metrics included the median neighborhood household income and the hardship index (a composite index including dependency, educational attainment, unemployment, poverty, per capita income, and crowded housing). The Breslow-Day test for homogeneity assessed the association of the delivery epoch and neighborhood deprivation with the preterm delivery outcomes. RESULTS: Of 16,544 eligible deliveries, 8.7% occurred preterm. The incidences of preterm delivery (8.4% vs 9.0%; P=.17), spontaneous preterm delivery (5.0 vs 5.4%; P=.27), and medically indicated preterm delivery (3.2% vs 3.5%; P=.47) were similar in the pandemic and prepandemic epochs. However, the preterm delivery (odds ratio, 0.78; 95% confidence interval, 0.64-0.96) and spontaneous preterm delivery (odds ratio, 0.76; 95% confidence interval, 0.59-0.99) decreased from the prepandemic to the pandemic epoch in those living in neighborhoods <50th percentile for median income (Breslow-Day P values.047 and.036, respectively). Similarly, the preterm delivery (odds ratio, 0.78; 95% confidence interval, 0.64-0.97) and spontaneous preterm delivery (odds ratio, 0.74; 95% confidence interval, 0.57-0.98) decreased for those inhabiting the neighborhoods in the highest-hardship quartile (Breslow-Day P values.045 and.029, respectively). CONCLUSION: The populations residing in socioeconomically disadvantaged neighborhoods experienced reductions in preterm delivery during the COVID-19 pandemic. Neighborhood-level social determinants of health offer insight into the complex etiologies that contribute to preterm delivery and provide opportunities for public health and equity-focused prevention strategies.