Intersectional inequities in maternal mortality: Examining the compounded risks for black birthing individuals with physical disabilities

Background: People who are Black and have physical disabilities likely face a dual burden of risk for maternal mortality due to enduring systemic oppression rooted in racism and ableism. Objective: To investigate maternal mortality risks among Black birthing individuals with physical disabilities in the United States and assess the potential compounding effect when these marginalized identities intersect. Methods: We conducted a historical cohort study using the 2004-2021 Healthcare Cost and Utilization Project Nationwide Inpatient Sample. The study included 8,263,997 delivery hospitalizations. We used modified Poisson regression to estimate unadjusted and adjusted relative risks (RR) of maternal mortality by race and physical disability status. We calculated the Relative Excess Risk due to Interaction (RERI) and Attributable Proportion (AP) to assess additive interaction between Black race and physical disability status. Results: After adjusting for covariates, compared to their White birthing individuals, their Black peers experienced about 2.5 times (RR = 1.48,95%CI:2.08-2.96) the risk of maternal mortality. Compared to birthing individuals without physical disabilities, those with physical disabilities experienced nearly 11 times the (RR = 10.72,95%CI:8.15-14.10) risk of maternal mortality. Our adjusted additive interaction analysis revealed a significant super-additive effect (RERI = 11.3; AP = 0.47); suggesting that the combined effect of having both marginalized identities was greater than the sum of the individual effects of each identity. Conclusions: Our findings provide evidence for substantial inequities in maternal mortality by Black race and physical disability status, with evidence of a compounding effect when these marginalized identities intersect. These results underscore the urgent need for intersectional approaches in maternal health interventions and policies.