Effect of Psychosocial Stimulation on Development of Iron-deficient Anemic Infants: A Randomized Controlled Trial

In developing countries, millions of young children have developmental deficits due to poor nutrition, lack of a stimulating environment, and poverty. In Bangladesh, where poor nutrition, poverty and poor parental education are highly prevalent, the implications are serious not only for the individuals' future but also for national development.

Iron deficiency and child development There is increasing evidence that iron deficiency anemia detrimentally affects children's development (Grantham-McGregor and Ani 2001). Many cross sectional studies have shown that iron deficiency is associated with poor psychomotor development and behavioral deficits in young children, and poor cognition and school achievement in school-aged children. Furthermore, longitudinal studies have observed that children who are anemic in the first 3 years of life continue to have poorer cognition, school achievement and psychosocial well being than children who were not anemic (Grantham-McGregor and Ani 2001). However, anemia is associated with many adverse social and economic family circumstances (Lozoff et al. 1991;de Andraca et al. 1990), which may adversely affect children's development.

Anemic children who were treated with iron, failed to catch up with non-anemic children in developmental levels in several studies (e.g. Walter et al. 1989;Lozoff et al. 1987;Lozoff et al. 1996). A few randomized, controlled trials of iron treatment have been conducted with anemic young children (Stoltzfus et al. 2001;Idjarinata and Pollitt 1993;Aukett et al. 1986;Friel et al, 2001). In two of the trials, anemic children under four (Stoltzfus et al. 2001) or two years (Idjarinata and Pollitt 1993) achieved better development from iron supplementation. One of these studies in Indonesia involved only 25 treated anemic children (Idjarinata and Pollitt 1993). The other study was in Zanzibar and included many children with malaria and some severely anemic children (Stoltzfus et al. 2001) and only children with Hb <80g/L showed significant benefits in motor development but improvement in language milestones occurred in children with all levels of Hb. Two other randomized trials failed to show clear benefits (Aukett et al. 1986;Friel et al, 2001). One of them (Aukett et al. 1986) used an insensitive screening test to measure developmental outcomes and the other (Friel et al, 2001) compared the effect of low and high iron formula on the development of low birth weight children and no benefit was found in the high iron group. The high iron children actually had more respiratory infections.

A recent meta-analysis of randomised trials (Sachdev et al, 2005) found that while there is evidence that older anemic children benefit from iron in cognition there is no convincing evidence from children under 27 months. However, three more recent randomized trials of iron supplementation were not included (Black et al, 2004; Lind et al, 2004, Freil et al 2003). One in Bangladesh (Black et al, 2004) found a non significant benefit to motor development from iron alone however the power of the study was extremely limited and the group receiving iron and zinc benefited in motor development. Both the Indonesian (Lind et al, 2004) and Canadian studies (Freil et al 2003) found benefits from iron treatment to infants' motor development but not to mental development. It has been suggested that the poor level of mental development found in IDA infants may be irreversible in some circumstances (Lozoff et al 2000).

Stimulation and child development Iron deficient children show less activity, more apathy and are less likely to explore their environment than iron replete children and thus acquire skills only slowly (Grantham-McGregor and Ani 2001). One reason for the failure of some anemic children to catch up in mental development to non-anemic children following treatment may be that they have missed opportunities to explore their environment. Thus, they may require extra play experiences to catch up in development. In addition, many anemic children come from homes with low levels of stimulation and other psychosocial disadvantages (Grantham-McGregor and Ani 2001), which may exacerbate their poor level of development.