Abstract
Introduction: To examine severe maternal morbidity (SMM) at the intersection of race and physical disability status using nationally representative data.
Methods: This study conducted a pooled cross-sectional analysis of delivery hospitalizations in 2025 using 2004-2022 Healthcare Cost and Utilization Project Nationwide Inpatient Sample (HCUP-NIS) data. Delivery hospitalizations and physical disabilities were identified using validated ICD-9/10-based algorithms. The primary outcome was SMM excluding blood transfusion-only cases. Secondary outcomes included SMM severity measured by number of SMM indicators (≥2 or ≥3); and specific SMM categories. Risk ratios were calculated using modified Poisson regression and evaluated additive interaction using the Relative Excess Risk due to Interaction (RERI) and Attributable Proportion (AP).
Results: Among 8,584,800 delivery hospitalizations, 88,389 (1.0%) were to women with physical disabilities. Black disabled women with 528 per 10,000 deliveries (528.0; 95%CI:492.8-565.5) had the highest rates of SMM, followed by White women with physical disabilities (213.9; 203.6-224.7), and Black women without physical disabilities (107.7; 95%CI:105.3-110.1). White women without physical disabilities with 61 per 10,000 deliveries (60.7; 95%CI:59.4-62.1) had the lowest rate of SMM. After adjustment, Black women with physical disabilities had 6.92 times the risk of SMM (95%CI:6.45-7.44) compared to White women without disabilities. The adjusted RERI for SMM was 2.07 (95%CI:1.67-2.47) and the AP due to interaction was 0.38 (95%CI:0.33-0.43), suggesting that 38% of excess risk among Black women with physical disabilities was attributable to the interaction between race and physical disability.
Conclusions: Black women with physical disabilities experience compounded risks of SMM that exceed the sum of risks associated with race or physical disability alone. These findings underscore the need for intersectional approach to develop effective interventions to improve maternal care quality and outcomes in this high-risk population.