Lactation counseling increases breast-feeding duration but not breast milk intake as measured by isotopic methods

The importance of exclusive breast-feeding in the first 6 mo of life is widely recognized, but most mothers still do not reach this goal. Several studies have shown that face-to-face lactation counseling is effective in increasing not only exclusive breast-feeding rates but also the total duration of breast-feeding. However, it is unclear whether counseling could increase breast milk intake. The purpose of this study was to evaluate the effect of lactation counseling on breast milk intake, assessed through the deuterium dilution method. This was a blind, randomized intervention trial of lactation counseling in a sample of 188 babies born in Pelotas, selected with the same criteria used for the WHO Multicentre Growth Reference Study (MGRS). The main outcomes were breast-feeding pattern and duration for all infants as well as breast milk intake for a subsample of 68 infants at the age of 4 mo. Mothers in the control group were almost twice as likely to stop breast-feeding by 4 mo as those in the intervention group (prevalence ratio 1.85; P = 0.04). Cox regression confirmed that the velocity of weaning was twice as high in the control group. Breast milk and total water intakes did not differ between the groups. The deuterium dilution technique proved to be a practical means of assessing breast milk intake. Lactation counseling reduced early weaning, but breast milk intake at 4 mo was not affected.