2.1. Setting, Study Design, and Participants
congenital malformations
The present study is a prospective cohort nested in a randomized clinical trial (registered with After childbirth, mothers who met the inclusion criteria were invited to participate in the study: full-term pregnancy (≥37 weeks) who had children with a normal birth weight (≥2500 g), and no impediment to breastfeeding (i.e., HIV/AIDS). Exclusion criteria were congenital malformations and twin pregnancies.After being informed of the study procedures, 90% of the mothers agreed to participate. All children were assessed at 6 months and 12 months, with further follow-up at 4, 8, and 12 years of age. The present study used data collected at birth and at 1 and 12 years of age. Three hundred ninety-seven children were assessed at 1 year of age. The number of participants recruited and retained at 12 years of age (