A Spatiotemporal Analysis of Socio-Environmental Patterns in Severe Maternal Morbidity: A Retrospective Birth Cohort

Abstract

AbstractObjectivesSevere Maternal Morbidity (SMM) is a group of pregnancy complications in which a woman nearly dies. Despite its increasing prevalence, there is little research that evaluates geographic patterns of SMM and the underlying social determinants that influence excess risk. This study examines the spatial clustering of SMM across South Carolina, US, and its associations with place-based social and environmental factors.MethodsHospitalized deliveries from 1999 to 2017 were analyzed using Kulldorff’s spatial scan statistic to locate areas with abnormally high rates of SMM. Patients inside and outside risk clusters were compared using Generalized Estimating Equations (GEE) to determine underlying risk factors.ResultsFinal models revealed that the odds of living in a high-risk cluster were 84% higher among Black patients (OR=1.84, p<.001), 30% higher among Hispanic and Latina patients (OR=1.3, p<.05), and 1.51 times more likely among women living in highly segregated and poorer minority communities (OR=1.51 p<.001). Odds for residing in a high-risk cluster were 23% higher for those who gave birth during a period with temperatures above 30.65°C/87.3°F (OR=1.23, p<.001).ConclusionsThis study is the first to characterize the geographic clustering of SMM risk in the US. Our geospatial approach contributes a novel understanding to factors which influence SMM beyond patient-level characteristics and identifies the impact of systemic racism on maternal morbidity. Findings address an important literature gap surrounding place-based risk factors by explaining the contextual social and built environment variables that drive SMM risk.SignificanceIt is not entirely clear why SMM is increasing in the US. Underlying health conditions, environmental, and social factors have been linked to higher SMM risk. This study is the first to assess these factors across space to determine the characteristics and locations where SMM likelihood is elevated.HighlightsFirst study to examine spatial patterning of severe maternal morbidity (SMM)SMM is geographically clustered and increasing in South Carolina, USAHighest risk for SMM in racially segregated low-income communitiesObesity and race were significant individual risk factorsHigh ambient temperatures corresponded with high SMM clustering