GROWTH OF BREAST-FED INFANTS DEVIATES FROM CURRENT REFERENCE DATA - APOOLED ANALYSIS OF US, CANADIAN, AND EUROPEAN DATA SETS

Objective. To compare growth patterns of a large sample of breast-fed infants with the current World Health Organization (WHO)/Centers for D isease Control and Prevention (CDC) reference data. Methods. Data from seven longitudinal studies of infant growth in North America and nort hern Europe were pooled (n = 453 breast-fed infants). Weight, length a nd head circumference were compared with the WHO/CDC reference, and re peated-measures analysis of variance was used to examine associations between growth patterns and breast-feeding duration, age of introducti on of solid foods, and use of other milks. Results. In comparison with WHO/CDC reference data, infants breast-fed for at least 12 months (n = 226) grew more rapidly in the first 2 months and less rapidly (parti cularly in weight) from 3 to 12 months; the mean z score at 12 months was -0.53 for weight for age, -0.29 for length for age, and -0.32 for weight for length. In contrast, mean head circumference was well above the WHO/CDC median throughout the first year of life. These patterns were generally consistent across studies. In the full sample (n = 453) , a longer duration of breastfeeding was associated with a greater dec line in weight for age and weight for length but not length for age. C onclusion. These results suggest that if growth charts are to reflect patterns consistent with those of infants following WHO feeding recomm endations, new reference data based on breast-fed infants are needed.