Geographic variation in pregnancy associated overdose and substance use disorder mortality, 2016 to 2022

ImportanceDrug-related pregnancy-associated mortality is a leading contributor to the US maternal mortality crisis, yet whether it follows the persistent rural disadvantage documented for all-cause maternal mortality--or is restructured by the geographic dynamics of drug markets--has not been established. ObjectiveTo characterize geographic variation in pregnancy-associated overdose (OD) and substance use disorder (SUD) mortality across the rural-urban continuum and by US Census region from 2016 through 2022. Design, Setting, and ParticipantsNational population-based surveillance study using individual-level National Vital Statistics System (NVSS) mortality and natality records. Pregnancy-associated deaths (occurring during pregnancy or within one year of the end of pregnancy) were ascertained among 25,007,723 live births during 2016-2022 using the NVSS 2018 algorithm. ExposuresRural-urban classification cross-classified by four US Census regions. Main Outcomes and MeasuresRates of pregnancy-associated OD mortality and SUD mortality per 100,000 live births. Post-COVID excess OD mortality was estimated using a Bayesian hierarchical Poisson model. ResultsThere were 516 OD deaths (2.06 per 100,000 live births) and 1,080 SUD deaths (4.32 per 100,000) nationally; SUD exceeded OD mortality more than two-to-one in all strata, and both outcomes were concentrated in the late postpartum period (43 days to 1 year). OD mortality converged across the rural-urban gradient during the COVID era (2020-2022)--the inverse of the persistent rural disadvantage in all-cause maternal mortality--with metropolitan areas falling below pre-pandemic trajectory expectations while non-metropolitan areas exceeded theirs. Credible excess OD mortality was identified in non-metropolitan Southern and Northeastern counties. SUD rates were non-monotonic across urbanicity, with metro-adjacent counties carrying elevated rates in all regions. Conclusions and RelevanceDrug-related pregnancy-associated mortality follows a distinct geographic logic from all-cause maternal mortality, shaped by drug supply dynamics and harm reduction geography rather than obstetric care infrastructure alone. The convergence of OD mortality across the rural-urban gradient, the dominance of SUD over acute overdose, and the concentration of deaths in the late postpartum year point to care and surveillance gaps requiring integrated obstetric and addiction treatment, extended postpartum insurance coverage, and rural harm reduction capacity.