Introduction: Simultaneous (SIM) breast expression saves mothers time compared with sequential (SEQ) expression, but it remains unclear whether the two methods differ in milk output efficiency and efficacy.
Subjects and methods: The Showmilk device (Medela AG, Baar, Switzerland) was used to measure milk output and milk ejection during breast expression (electric pump) in 31 Australian breastfeeding mothers of term infants (median age, 19 weeks [interquartile range, 10-33 weeks]). The order of expression type (SIM/SEQ) and breast (left/right) was randomized.
Results: SIM expression yielded more milk ejections (p ≤ 0.001) and greater amounts of milk at 2, 5, and 10 minutes (p ≤ 0.01) and removed a greater total amount of milk (p ≤ 0.01) and percentage of available milk (p<0.05) than SEQ expression. After SIM expression the cream content of both the overall (8.3% [p ≤ 0.05]) and postexpression (12.6% [p ≤ 0.001]) milk were greater. During SEQ expression, the breast expressed first had a shorter time to 50% and 80% of the total amount of milk than the breast expressed second (p ≤ 0.05), but, overall, a similar percentage of available milk was removed from both breasts.
Conclusions: SIM expression stimulated more milk ejections and was a more efficient and efficacious method of expression, yielding milk with a higher energy content.