P1109* EFFECT OF IRON SUPPLEMENTATION IN PREGNANCY ON IQ OF CHILDREN AT 4 YEARS OF AGE

Abstract

Introduction: Evidence from animal studies has consistently demonstrated that inadequate iron nutrition during pregnancy leads to permanent structural and functional changes in the brain of offspring. However, there are no human trials specifically designed to examine the effect of iron supplementation in pregnancy on childhood neurodevelopment. Our aim was to assess the IQ of children at 4 years of age whose mothers had previously participated in a double blinded randomised controlled trial (RCT) of iron supplementation in pregnancy [1]. Methods: Families who participated in the RCT [1] during 1997–1999 were invited to participate in a follow up study when the children were 4 years of age. The IQ of the children was assessed using the Stanford– Binet Intelligent Test (4th Ed). Weight, height and head circumference were measured and iron status was assessed. Additional information on possible confounders of child development such as home environment and length of breastfeeding are also collected. Results: Seventy-seven percent (303/391) of the children from the original trial consented to participate in the follow up study, 8% (31/391) were lost to follow up and 15% (57/391) refused to participate. Data collection is complete for 290/303 children and 13 children remain to be assessed to complete the study. Results collected to date show that the mean age of children at assessment is 4.17 ± 0.23 years. The mean total IQ for children assessed thus far (n=290) is 109 ± 11, while verbal IQ is 109 ± 12, visual IQ is 104 ± 10, quantitative reasoning IQ is 114 ± 12 and short-term memory IQ is 104 ± 12. Mean haemoglobin at assessment is 123 ± 7 g/L (n=210) and mean serum ferritin is 21 ± 12 ug/l (n=209). Data collection is ongoing and will be completed by the end of December 2003. Primary comparisons will be made between the IQ of children from iron supplemented mothers and the IQ of children from placebo supplemented mothers. Adjustment will be made for possible confounding variables. We are unable to perform the statistical analysis for the primary comparisons at this stage as we can not unblinded the trial until all data collection is complete. Conclusion: If iron supplementation in pregnancy results in higher IQ of children, we believe that this will necessitate a reevaluation of the critical period of iron nutrition for influencing neurodevelopment.