Efficacy of breast milk expression using an electric breast pump.

The authors compared breastfeeding and expression characteristics in 30 mothers of exclusively breastfeeding, healthy term infants. Mean (+/- SD) volume per breastfeed from one breast was 71.8 +/- 26.3 mL, and mean duration per breastfeed for one breast was 16.6 +/- 10.5 minutes. Mean volume of milk expressed in 5 minutes from one breast was 60.6 +/- 39.0 mL and corresponded to the expression of 99.4 +/- 82.6% of the milk stored in the breast. The rate of milk expression differed greatly between mothers (P = .0001) but remained constant for the first 2.5 minutes before decreasing with time (P = .0001). These results show the mean breastfeed volume was similar to the volume of milk expressed in a 5-minute period. Furthermore, this study is the first to establish protocols that allow for the objective determination of breast pump efficacy.