Breast feeding and cognitive development at age 1 and 5 years

Aim-To examine whether duration of breast feeding has any effect on a child 's cognitive or motor development in a population with favourable environme ntal conditions and a high prevalence of breast feeding. Methods-In 345 Scandinavian children, data on breast feeding were prospecti vely recorded during the first year of life, and neuromotor development was assessed at 1 and 5 years of age. Main outcome measures were Bayley's Scal es of Infant Development at age 13 months (Mental Index, MDI; Psychomotor I ndex, PDI), Wechsler Preschool and Primary Scales of Intelligence (WPPSI-R) , and Peabody Developmental Scales at age 5. Results-Children breast fed for less than 3 months had an increased risk, c ompared to children breast fed for at least 6 months, of a test score below the median value of MDI at 13 months and of WPPSI-R at 5 years. Maternal a ge, maternal intelligence (Raven score), maternal education, and smoking in pregnancy were significant confounders, but the increased risk of lower MD I and total IQ scores persisted after adjustment for each of these factors. We found no clear association between duration of breast feeding and motor development at 13 months or 5 years of age. Conclusion-Our data suggest that a longer duration of breast feeding benefi ts cognitive development.