Beyond 42 Days: A National Cohort Study of Maternal and Late Maternal Deaths in Brazil from 2010 to 2023.

Maternal mortality is a serious public health problem and reflects social, ethnic, racial, and regional inequalities in access to and quality of obstetric care. Despite advances in the surveillance and investigation of maternal deaths in Brazil, late maternal deaths (occurring between 43 days and 1 year after birth) are still underestimated and underexplored. Therefore, the objective of this study was to analyze the distribution and factors associated with maternal deaths and late maternal deaths in Brazil between 2010 and 2023. This was a population-based, retrospective cohort study with a quantitative approach, using secondary data from the Mortality Information System. All maternal deaths (Chapter XV of ICD-10) and late deaths recorded during the period were included. Sociodemographic, clinical, and administrative variables were analyzed. Statistical tests of association (chi-square, test of proportions, and 95% CI) were used, with a significance level of 5%. A total of 26,953 deaths were identified, of which 24,387 were maternal and 2566 were late deaths. Most deaths occurred among single, mixed-race women with 8 to 11 years of schooling, and residing in the Southeast region. Late deaths were more frequent in the South and among women aged 40 to 49. The main causes were direct obstetric conditions. A statistically significant association was observed between the type of death and sociodemographic variables. The results highlight structural inequalities in maternal mortality in Brazil and reinforce the importance of expanding postpartum surveillance beyond 42 days, with a focus on equity and continuity of care.