Maternal Mortality Trends in Brazil: A Decomposition Analysis

Despite recent advances in obstetric health services, maternal mortality remains a major public health challenge in Brazil. In 2019, the country recorded 57 maternal deaths per 100,000 live births; by 2021, this figure had risen sharply to 128 deaths per 100,000 live births, substantially increasing Brazil’s distance from the United Nations Sustainable Development Goals (SDG) target 3.1 of 30 maternal deaths per 100,000 live births to be achieved by 2030. Maternal mortality risks are known to vary substantially by maternal age, and Brazil has experienced a steady increase in the mean age at childbearing due to fertility postponement. As a result, recent changes in the Maternal Mortality Ratio (MMR) may reflect two distinct but interrelated mechanisms: shifts in the age composition of live births toward older maternal ages and changes in age-specific mortality risks. However, most existing studies focus on aggregate trends or disparities, offering limited insight into the relative contribution of these mechanisms. The objective of this study is to decompose recent changes in the Maternal Mortality Ratio in Brazil at the subnational level, by maternal age and cause of death. Analogous to the crude death rate, the MMR can be expressed as the weighted sum of age-specific mortality risks, combining a compositional component, the proportion of live births by maternal age, and a mortality component, the ratio of maternal deaths to live births at each age. Maternal deaths are further disaggregated by cause, allowing the application of demographic decomposition methods to disentangle the effects of compositional changes and shifts in mortality risks, and to identify the causes driving recent trends in maternal mortality in Brazil.