OBJECTIVE: This study assessed the growth of exclusively breastfed infants until six months of age and compared their weight and length with those of the National Center for Health Statistics 1978 reference, and the World Health Organization standard 2006. METHODS: This was a longitudinal research done at the Human Milk Bank of São Luis, Maranhão, from October 2007 to November 2008. The non-probabilistic sample consisted of 328 exclusively breastfed, full-term infants. A total of 181 infants concluded the study. Growth was assessed by means and standard deviation and the results were compared with those of the National Center for Health Statistics 1978 and World Health Organization 2006. RESULTS: Males weighed more than females from the first to the sixth month (p<0.05). The greatest weight gain occurred in the first two months of life for both sexes. The mean female weight was higher than that of the World Health Organization 2006 at birth and from the third to the sixth month (p<0.05); meanwhile, males were heavier from the fourth to the sixth month (p<0.05), but their weights were higher than those of the National Center for Health Statistics 1978, for both genders, from birth to the sixth month (p<0.05), except for males at birth. The mean male lengths were lower than those of the World Health Organization 2006 from birth to the sixth month (p<0.05), except for the fifth month; they were also lower than the National Center for Health Statistics 1978 at birth and in the first, fourth and sixth months of life (p<0.05); female heights were similar to those of the World Health Organization 2006 and lower than those of the National Center for Health Statistics 1978 at birth and at the sixth month (p<0.05). CONCLUSION: The weight gain of exclusively breastfed children was more similar to that of the World Health Organization 2006 standard than that of the National Center for Health Statistics 1978 reference. Linear growth was appropriate, similar to both the standard and the reference.
Breast feeding; Anthropometry; Growth
