Use of the isotope method to measure breast milk intake

A study to test the efficacy of the nutrition counselling (NC) contents of integrated Management of Childhood Illnesses Course (IMCI, WHO/UNICEF), funded by WHO, was planned and conducted in Pelotas (southern Brazil). The study was a single-blind randomized controlled trial with the random allocation of 14 municipal health centres to receive the NC training and 14 other centres to the control group (current nutrition counselling, if any). The study included testing the knowledge of doctors, observing consultations and visiting the children at home 8, 45 and 180 days after the initial consultation. Dietary intakes were studied on a sub-sample of 66 children (two per health care provider), through daylong observations. Breast milk intake was assessed by the frequency and duration of feeds. The deuterium study was carried out in the same population to validate breast milk intake estimates. The deuterium study was a cross-sectional assessment of breast milk intake among those children enrolled in the day long sub-sample. From the 66 children visited by the day long study, 18 were still breast fed and were selected for the deuterium study. A total of 11 saliva samples were collected from each mother/child pair at a 15-day interval: four from the mother (on days 0, 1, 6 and 14) and seven from the child (on days 0, 1, 2, 5, 6, 13, and 14). The Pearson correlation coefficient comparing the amount of milk as estimated by observation and the amount calculated through the deuterium technique (gold standard) was equal to 0.53. This result indicates that the estimates based on the frequency and the duration of breastfeeding through observation correlated to the results of the gold standard method for breast milk intake assessment, although this correlation was of moderate strength. As the gold standard, the deuterium method showed to be practical and easily to perform at field setting. (author)