Objective: To describe racial and ethnic disparities in the incidence of severe maternal morbidity during delivery hospitalizations in the United States.
Methods: We conducted a pooled, cross-sectional analysis of 2012-2015 data from the National Inpatient Sample to define the prevalence of chronic conditions and incidence of severe maternal morbidity among deliveries to non-Hispanic white, non-Hispanic black, Hispanic, Asian or Pacific Islander, and Native American or Alaska Native women. We used weighted multivariable logistic regression and predictive margins to generate prevalence and incidence estimates. Adjusted rate ratios and differences were calculated to quantify disparities across racial and ethnic categories. Subgroup analyses were performed to examine the incidence of severe maternal morbidity among deliveries to women with comorbid physical health conditions, behavioral health conditions, and multiple chronic conditions within each racial and ethnic category.
Results: The incidence of severe maternal morbidity was significantly higher among deliveries to women in every racial and ethnic minority category compared with deliveries among non-Hispanic white women. Severe maternal morbidity occurred in 231.1 (95% CI 223.6-238.5) and 139.2 (95% CI 136.4-142.0) per 10,000 delivery hospitalizations among non-Hispanic black and non-Hispanic white women, respectively (P<.001). When excluding cases in which blood transfusion was the only indicator of severe maternal morbidity, only deliveries to non-Hispanic black women had a higher incidence of severe maternal morbidity compared with deliveries among non-Hispanic white women: 50.2 (95% CI 47.6-52.9) and 40.9 (95% CI 39.6-42.3) per 10,000 delivery hospitalizations, respectively (risk ratio 1.2 [95% CI 1.2-1.3], risk difference 9.3 [95% CI 6.5-12.2] per 10,000 delivery hospitalizations; P<.001 for each comparison). Among deliveries to women with comorbid physical and behavioral health conditions, significant differences in severe maternal morbidity were identified among racial and ethnic minority compared with non-Hispanic white women and the largest disparities were identified among women with multiple chronic conditions.
Conclusion: Programs for reducing racial and ethnic disparities in severe maternal morbidity may have the greatest effect focusing on women at highest risk for blood transfusion and maternity care management for women with comorbid chronic conditions, particularly multiple chronic conditions.