Social and biological determinants of growth and development in underprivileged societies

Abstract

The stimulating study by da Rocha Neves et al. (in this issue)1 addresses the role of social and biological factors in growth and development of young children in a disadvantaged society. The authors assessed a group of 92 children, aged 24--36 months, who in 2011 attended the municipal early childhood education network in a town in the Vale do Jequitinhonha region. This region in the southeast of Brazil is considered economically underprivileged. The study was restricted to children with typical development, which meant that the children did not suffer from an evident congenital or acquired disability. Growth was assessed by means of standard anthropometrics, with a focus on heightfor-age, a valid tool to assess childhood malnutrition.2 Development was measured with the Bayley Scales of Infant and Toddler Development (BSITD-III),3 the gold standard to measure developmental outcome at early age. The cognitive score and the expressive language scores were used as outcome parameters. Biological risk was assessed by a few perinatal factors, such as gestational age at birth, birth weight, pregnancy complications, and the number of prenatal consultations, and a few childhood parameters, including breastfeeding, the presence of chronic diseases,