Prevalence and trends of major congenital anomalies in Brazil: A study from 2011 to 2020

Background Congenital anomalies contribute significantly to morbidity and mortality among newborns and infants. In Brazil, the estimated prevalence of malformations in newborns is < 1%, which is comparatively lower than that recorded in other regions worldwide. This study aimed to analyze the prevalence of congenital anomalies in Brazil over a 10-year period and to identify potential associations of this prevalence with socioeconomic, gestational, and regional factors by performing an analysis using data sourced from the Live Birth Information System (Sistema de Informações sobre os Nascidos Vivos – SINASC) covering the period from 2011 to 2020. Methods From a total population of 29,025,461 live births, we included a cohort of 240,405 newborns with congenital anomalies. For the purpose of this study, we categorized newborns with congenital anomalies into two groups: one group with newborns with a single major malformation and another group with newborns with multiple major malformations (minor malformations not considered). Results The prevalence of congenital anomalies was 8.0 per 1,000 live births, with variations across different years and regions within the country. The Southeast region of Brazil, with the highest human development index, displayed the highest prevalence of congenital anomalies. The most frequent congenital anomalies were limb deformities (29.7%), neural tube defects (14.7%), and heart defects (11.6%). Conclusion The prevalence of major congenital anomalies in Brazil during the study period varied with the geographic region and was lower than that in developed nations, likely due to lower prenatal detection rates and underreporting.