Accuracy of single- and two-feed test weighing in assessing 24 h breast milk production.

The breast milk intake at a single feed (one-feed method) or the mean intake at two feeds (two-feed method) multiplied by the number of feeds per day was compared with the results of test weighing at every feed during a 24 h period. Six subjects were followed longitudinally from days 1-9 and 21-56 postpartum and the data analyzed by linear regression. There was a reasonable relationship between the mean values for milk intake obtained from the one- and two-feed methods and the 24 h test weights between days 3 and 9 of lactation. However, there was no relationship in full lactation (days 21-56). During both time periods, individual values for the one- and two-feed methods were associated with a large unsystematic error. The one- and two-feed methods may be useful only in situations where mean milk intake for a large population is desired and 24 h test weighing is not possible.