Jonsdottir, Olof H.Thorsdottir, IngaGunnlaugsson, GeirFewtrell, Mary S.Hibberd, Patricia LavonneKleinman, Ronald2014-03-112013Jonsdottir, Olof H., Inga Thorsdottir, Geir Gunnlaugsson, Mary S. Fewtrell, Patricia L. Hibberd, and Ronald E. Kleinman. 2013. “Exclusive Breastfeeding and Developmental and Behavioral Status in Early Childhood.” Nutrients 5 (11): 4414-4428. doi:10.3390/nu5114414. http://dx.doi.org/10.3390/nu5114414.2072-6643http://nrs.harvard.edu/urn-3:HUL.InstRepos:11879253Breastfeeding during infancy may have beneficial effects on various developmental outcomes in childhood. In this study, exclusively breastfed infants were randomly assigned to receive complementary foods from the age of 4 months in addition to breast milk (CF, n = 60), or to exclusively breastfeed to 6 months (EBF, n = 59). At 18 months and again at 30–35 months of age, the children were evaluated with the Parent’s Evaluation of Developmental Status questionnaire (PEDS) and the Brigance Screens-II. The parents completed the PEDS questionnaire at both time intervals and the children underwent the Brigance Screens-II at 30–35 months. At 30–35 months, no significant differences were seen in developmental scores from the Brigance screening test (p = 0.82). However, at 30–35 months a smaller percentage of parents in group CF (2%) had concerns about their children’s gross motor development compared to those in group EBF (19%; p = 0.01), which remained significant when adjusted for differences in pre-randomization characteristics (p = 0.03). No sustained effect of a longer duration of exclusive breastfeeding was seen on selected measures of developmental and behavioral status at 18 months, although at 30–35 months, a smaller percentage of parents of children introduced to complementary foods at four months of age expressed concerns about their gross motor development.en-USearly childhoodexclusive breastfeedingcomplementary feedingdevelopmental statusbehaviorrandomized trialISRCTN41946519Journal Article2014-03-1110.3390/nu5114414