Cohort Profile: The 2004 Pelotas (Brazil) Birth Cohort Study

The last decades of the 20th century witnessed a major epidemiological and nutritional transition in Latin America. Mortality due to infectious diseases and malnutrition declined in most countries and neonatal deaths now account for a growing proportion of infant deaths. In Brazil, infant mortality fell from 82.8 per 1000 live births in 1980 to 27.4 per 1000 in 2000. There were also marked improvements in undernutrition: 37.1% of Brazilian children <5 years of age were stunted in 1974 compared with 10.5% in 1996. Because of the speed of epidemiological and nutritional changes, and motivated by the successful implementation and follow-up of two previous population-based birth cohorts in 1982 and 1993, the research team decided to start a new cohort in 2004 to assess the magnitude of changes in maternal and child health status and their determinants. The existence of three prospective birth cohorts in the same population would provide a unique opportunity to study time trends over a 22-year span.