“…Previous studies identified age of children, sex of children, gestational weeks, economic status, prenatal micronutrients supplementation, birthweight and other social backgrounds as detrimentally affecting cognitive development of children 22 , 28 , 33 , 34 . In addition, the majority of variables mentioned above were also reported as being associated with physical growth of children in previous studies 35 – 37 . Therefore, we considered the following variables as potential confounders in the multivariate adjusted analysis: age of children, age of parents, sex of children, gestational weeks at birth, type of micronutrient supplement, household wealth index, older siblings of children, birthweight, educational level of parents, father’s occupation of parents, child school level.…”