Maternal internal migration and child growth and nutritional health in Peru: an analysis of the demographic and health surveys from 1991 to 2017

Peru has historically experienced high rural-to-urban migration. Despite large reductions in undernutrition, overweight is increasing. Elsewhere, internal migration has been associated with differences in children's growth and nutritional health. We investigated how child growth and nutritional status in Peru varied over time and in association with maternal internal migration. Using data from Demographic & Health Surveys from 1991 to 2017, we assessed trends in child growth (height-for-age [HAZ], weight-for-age [WAZ], weight-for-height [WHZ] z scores) and nutritional health (stunting, underweight, overweight) by maternal adult internal migration (urban [UNM] or rural non-migrant [RNM], or urban-urban [UUM], rural-urban [RUM], rural-rural [RRM], or urban-rural migrant [URM]). Using 2017 data, we ran regression analyses, adjusting for confounders, to investigate associations of maternal migration with child outcomes and the maternal and child double burden of malnutrition. We further stratified by timing of migration, child timing of birth and, for urban residents, type of area of residence. Results are given as adjusted predictive margins (mean z score or %) and associated regression p-values [p]. In 1991-2017, child growth improved, and undernutrition decreased, but large differences by maternal migration persisted. In 2017, within urban areas, being the child of a migrant woman was associated with lower WHZ (UUM = 0.6/RUM = 0.5 vs UNM = 0.7; p = 0.009 and p