Postpartum severe maternal morbidity: A longitudinal analysis of the association with economic segregation and neighborhood deprivation in Georgia, USA 2016-2022.

Severe maternal morbidity (SMM) is a composite measure comprising a spectrum of pregnancy-related complications that have substantial implications for short- and long-term maternal health. Existing research focuses primarily on the occurrence of SMM at delivery, but growing evidence points to risks throughout the post-partum period. While racial, ethnic, economic, and geographic disparities in SMM are well documented, the underlying drivers of inequities, particularly the roles of socio-spatial stratification and access to health services, are not well understood. Using a longitudinally-linked cohort of 637,932 hospital deliveries between 2016 and 2022 we examined two questions: (1) Does the race-specific association between neighborhood deprivation (NDI) or the index of concentration at extremes for income (ICE) and SMM vary by time period of SMM (delivery, 3 months after delivery, or up to 12 months postpartum)? (2) Are these associations modified by policy-relevant health service indicators, including payor, proximity to Federally Qualified Health Centers, and availability of OB-GYN's? Half of all SMM events occurred in the postpartum year. NDI was not significantly associated with SMM at delivery for Hispanic, Non-Hispanic White or Black individuals, but was positively associated with SMM between 3 and 12 months for all race/ethnic groups. Living in areas of concentrated affluence was protective against postpartum SMM for non-Hispanic Black individuals while concentrated poverty was associated with higher postpartum SMM risk for Hispanic and non-Hispanic Black women. Place-based structural disadvantage is a key determinant of postpartum SMM and disparities in SMM rates.