Response of breasts to different stimulation patterns of an electric breast pump

J Hum Lact. 2003 May;19(2):179-86; quiz 87-8, 218. doi: 10.1177/0890334403252473.


To test the effect on milk ejection, an electric breast pump was programmed to provide pumping patterns with frequencies of 45 to 125 cycles/min and vacuums of 45 to -273 mm Hg. The time taken for milk ejection to occur (measured using ultrasound to detect a dilation of a lactiferous duct in the opposite breast) in response to the current Medela electric breast pump pattern (45 cycles/min) was 147 +/- 13 s. For patterns that more closely resemble the sucking frequency of an infant when it first attaches to the breast, milk ejection occurred between 136 +/- 12 and 104 +/- 10 s, although this difference was not statistically significant. Milk ejection in response to breastfeeding occurred after 56 +/- 4 s. The applied vacuum affected the amount of milk that was removed up to 50 to 70 s after milk ejection but not the time for milk ejection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Breast / physiology*
  • Breast Feeding
  • Female
  • Humans
  • Lactation / physiology*
  • Milk Ejection / physiology*
  • Suction
  • Vacuum