The effect of maternal fluid intake on breast milk supply: a pilot study

To examine the effect of increased and decreased fluids on breast milk supply, a pilot study using a cross-over design with 10 mother-infant pairs was completed. Baseline measures of milk supply were determined over a 3-day period of normal fluid intake based on body weight. Subjects were studied over 3-day periods when fluid intake was alternately 50% more and 50% less than normal level. Milk supply was calculated by averaging breast milk intake, determined by test weighing the infants with electronic scales, and milk yield, measured either by total breast expression with an electric breast pump or a combination of expression and test weighing. Although milk supply decreased with decreased fluids and increased with increased fluids, this change was not statistically significant. Recommendations for further research include replication using subjects' usual fluid intake as a baseline and replication using mothers suspected of insufficient milk syndrome.