Racial and ethnic disparities are pervasive in maternal health and a major source of health inequities in many settings. For example, maternal mortality rates persistently highlight racial disparities in high-income countries, such as the United States (US) and United Kingdom (UK). Studies of composite severe maternal morbidity across racial groups in Europe, Australia, and North America have shown similar trends. However, we have yet to understand the relationship between race/ethnicity and severe maternal morbidity and severe perinatal morbidity/mortality in Canada.

Maternal morbidity occurs more frequently than maternal mortality and can serve as a more practical measure to identify quality improvement targets. Such an approach may not only result in reductions in maternal morbidity, but ultimately, in maternal mortality as well by addressing its clinical antecedents. Identifying pregnant individuals at heightened risk of these outcomes is critically important, as severe morbidity and mortality can be avoided with appropriate mobilization of resources and hemorrhage preparedness. Previous studies suggest that racialized groups experience higher rates of these outcomes, however, these analyses have been compromised by data limitations as well as a lack of methodological rigour and generalizability. Further, underlying causes of disparities in these morbidity/mortality outcomes among racial/ethnic groups remain unclear. Consequently, there is a pressing need to understand racial/ethnic disparities in severe maternal morbidity and severe perinatal morbidity/mortality and to investigate the causes of these disparities in order to drive equitable solutions to address disparities in maternal health.

Ontario, the most populous province in Canada, has a high level of racial/ethnic diversity and collects detailed and validated clinical, demographic and socioeconomic information through linked population-based datasets, providing a unique opportunity to examine racial/ethnic variations in severe maternal and perinatal outcomes. This study uses linked population-based data from demographic, hospital admission, and birth registries to study severe morbidity in moms and babies in a population of over 860,000 pregnancies. The diversity of the study population, comprehensiveness of the data sources, and application of robust design and analytical approaches will ensure high internal and external validity and allow us to interrogate the relationship between race/ethnicity and severe morbidity. These results will be used to promote equity in maternity care and stimulate further race/ethnic-based analyses in Canadian perinatal research.