A method for the measurement of milk intake in young breast-fed babies is described in which heavy water (2H2O) enrichment in saliva is measured on only two occasions after a single oral dose of 2H2O. Values obtained by this method are compared with those obtained by test-weighing. This new method is ideal for routine surveys since it does not interfere with feeding habits and maternal life style, and no technical expertise is required of the mother.
PIP: In order to determine how long breast milk can satisfy completely the nutritional needs of infants, there must be an accurate method for assessing the range of maternal milk output throughout lactation. Both test-weighing and milk expression interfere with customary feeding patterns and normal mother-infant interactions. Sensitive mass spectrometer techniques now permit the measurement of low levels of water samples enriched with nonradioactive, heavy water. The method is described. 6 mothers of infants in England and Gambia allowed the method to be attempted with their babies. The laboratory procedures and analytical techniques are described and the results are graphed. The measurement showed milk intake by the level of heavy water enrichment in the saliva after a single oral dose of enriched water. In all but 1 of the 6 babies, the values obtained with the new method were about the same as those obtained by test-weighing; test-weighing results for the 6th child were very much too low, judged from the baby's weight gain. The new procedure does not provide information about intake at individual feeds. It does give an average of daily milk intake over a more representative period. The new method is preferable because the mother needs no technical expertise to perform the study.