Reliability and Validity of Swallows as a Measure of Breast Milk Intake in the First Days of Life

Background: Breastfeeding assessment in the hospital to determine adequacy of feeds remains controversial. Swallow evaluation is integral to current assessment tools, but the literature is not clear about whether the number of swallows is an accurate indicator of breast milk intake in early postpartum. Objectives: To determine the reliability and validity of swallows as a measure of breast milk intake in the first days of a newborn’s life. Methods: Thirty mother-baby dyads were observed at one breastfeeding; pre- and postfeed weights were done, bedside audible swallows were counted, and feeds were videotaped for independent rating. Milk intake was determined from weight change, adjusted for insensible water loss. Results: Number of swallows was significantly and positively correlated with breast milk intake (r = .71). Number of swallows alone, however, accounted for only 50.8% (R2 = .508) of the variation in milk intake. Infant age was the best predictor of milk intake (ßage = .56 vs ßNo. swallows = .36), accounting for 68% of the variation in milk intake when combined with swallows. The majority of infants took in 10 g or less of breast milk (77%); length of feeds was variable. In-room (at bedside) lactation consultant (LC) and video rater LC swallow counts were significantly and positively correlated (r = .93;P < .01). However, the 2 lactation consultant swallow numbers include clinically important discrepancies in a Bland-Altman analysis. Conclusions: Number of swallows was not supported as a reliable or valid indicator of milk intake and adequacy of a feed in the first few days of life