COHORT PROFILE Cohort Profile: The 1993 Pelotas (Brazil) Birth Cohort Study

How did the study come about? In 1982, a birth cohort study was initiated in Pelotas, a Southern Brazilian city with a current population of 323 000 inhabitants. It started as a perinatal survey and later became one of the largest and longest running birth cohorts in the developing world. With the success of this initial study, our group decided to propose a second birth cohort, to be launched 10 years later. Due to delayed funding, the new cohort could only start in 1993. Funding for the new cohort was obtained from the European Economic Commission, in a collaboration that included the London School of Hygiene and Tropical Medicine and the Escuela Andaluza de Salud Publica from Granada. In the late 80s and early 90s, the hypothesis that intrauterine, infant and child growth could affect long-term health outcomes gained widespread attention. The beneficial effects of breastfeeding were also becoming more evident. To better describe growth and feeding patterns, we opted to examine infants on several occasions, at the ages of 1, 3, 6 and 12 months, differently from our 1982 cohort when the first home visit took place at the age of 9–15 months.