Iron deficiency anemia: adverse effects on infant psychomotor development.

In a double-blind, placebo-control prospective cohort study of 196 infants from birth to 15 months of age, assessment was made at 12 months of age of the relationship between iron status and psychomotor development, the effect of a short-term (10-day) trial of oral iron vs placebo, and the effect of long-term (3 months) oral iron therapy. Development was assessed with the mental and psychomotor indices and the infant behavior record of the Bayley Scales of Infant Development in 39 anemic, 30 control, and 127 nonanemic iron-deficient children. Anemic infants had significantly lower Mental and Psychomotor Developmental Index scores than control infants or nonanemic iron-deficient infants (one-way analysis of variance, P less than .0001). Control infants and nonanemic iron-deficient infants performed comparably. No difference was noted between the effect of oral administration of iron or placebo after 10 days or after 3 months of iron therapy. Among anemic infants a hemoglobin concentration less than 10.5 g/dL and duration of anemia of greater than 3 months were correlated with significantly lower motor and mental scores (P less than .05). Anemic infants failed specifically in language capabilities and body balance-coordination skills when compared with controls. These results, in a design in which intervening variables were closely controlled, suggest that when iron deficiency progresses to anemia, but not before, adverse influences in the performance of developmental tests appear and persist for at least 3 months despite correction of anemia with iron therapy. If these impairments prove to be long standing, prevention of iron deficiency anemia in early infancy becomes the only way to avoid them.