Racial inequities in severe maternal morbidity among Black and White people in Canada: a population-based cohort study, 2012 to 2023.

backgroundInternationally, rates of severe maternal morbidity (SMM) are consistently higher among Black people than White people; however, in Canada, such disparities remain poorly understood. We sought to assess racial inequities in SMM among Black and White people in Canada.

methodsWe conducted a population-based cohort study of in-hospital live births in Canada (excluding Quebec) from 2012 to 2023 using a Statistics Canada data set linking hospitalization and Census data. We included people who self-identified their race as Black or White. We defined SMM as a composite of diagnoses and procedures associated with high case fatality and prolonged hospitalization. We assessed frequencies of SMM overall and by SMM type, province or territory, year, and household income. We used logistic regression to estimate the association between race (as a social construct) and SMM, adjusted for maternal sociodemographic and clinical characteristics. All analyses used person-based weights for national representativeness.

resultsWe included 108 365 in-hospital deliveries to Black people and 1 385 810 in-hospital deliveries to White people that occurred between 2012 and 2023. Overall, SMM occurred in 47.8 and 27.7 per 1000 live births among Black and White people, respectively. The most common SMM type in both groups was severe preeclampsia (Black: 11.1, White: 6.7 per 1000 births). Rates of SMM were stable across years but varied by province or territory, with the largest disparity by race in New Brunswick (odds ratio [OR] 2.28, 95% confidence interval [CI] 1.46 to 5.43). Additionally, rates of SMM declined with increasing income among White people but increased with increasing income among Black people. After multivariable adjustment, Black people remained at higher risk of SMM (adjusted OR 1.66, 95% CI 1.53 to 1.80).

interpretationIn Canada, Black people have a higher risk of SMM than White people after adjustment for sociodemographic and clinical factors. Equity-driven policies and care models centring Black communities are urgently needed.