Medela Breast Pumps

Double Pumping

The benefits of Double Pumping (simultaneous breast expression) compared to single pumping (one breast followed by the other breast), are well known, but the latest scientific research has not only confirmed this, but has also uncovered further benefits for pumping mothers.


  • Up to 18% more milk during double pumping compared to single pumping
  • Provides milk with higher energy content, especially beneficial for preterm infants
  • High energy content indicates increased breast drainage, thereby assisting in the maintenance of lactation
  • Increased levels of prolactin – leading to increased milk output
  • Twice as fast as single pumping to get the same amount of breastmilk. Ideal for mothers of twins.

It is due to these crucial benefits that Double Trouble encourages expectant mommies of multiples to consider Double Pumping once the babies arrive especially if the babies are born prematurely. The benefits of Double Pumping have been carefully researched and so you may be wondering how these benefits are achieved so lets explain how it works!

Increased Milk Output

Double pumping has always been recognized as having a time saving advantage for mothers, but it also results in increased milk output for mothers. In the early 1990's Auerbach et al compared double to single breast pumping using four different pumping regimes (5-minute single, 5-minute double, unlimited single and unlimited double) in mothers of full term babies. The greatest amount of milk was collected when double pumping was allowed to continue until milk was no longer entering the collection chamber (unlimited double pumping). Another important outcome was that by a margin of 3:1, mothers preferred the double pump system, even those that achieved more milk with single pumping.

Brand new research has revisited this question. Prime et al investigated mothers of full term babies pumping their milk with an electric breastpump for 15 minutes on two occasions. On one day mothers would double pump, and on the other single pump. Compared to single pumping, double pumping yielded greater milk volumes and resulted in increased breast drainage (Increased percentage of available milk removed). In addition, double pumping also yielded milk with higher energy content. This study builds nicely upon previous research of Jones et al who also found an increase in milk energy content during double pumping.

Increased Number of Milk Ejection Reflexes (MERs)

The neurohormonal milk ejection reflex, with the key hormone oxytocin, is crucial for milk removal and maintenance of lactation. Milk flows from the breast during a milk ejection reflex (MER). MERs are described as short discrete uncoordinated increases in intraductal pressure, milk duct diameter and milk flow rate. They occur in both breasts at the same time, and mothers can have varying numbers of MERs during breastfeeding/breast pumping with a range of 1-17. During breast pumping, recent research has shown that mothers have one of four patterns of MER. These patterns are differentiated by both the number and shape of MERs during milk removal. This explains why milk removal varies between mothers, some mothers will remove milk quickly while others will need a bit more time. Interesting, if you follow the same mother over time, she will continue to have the same pattern of MER or milk release all the way out to 9-months of lactation.

When milk ejection reflexes were measured during double and single pumping by Prime et al, it became clear why double pumping yielded more milk volume and drained the breast better - double pumping actually stimulates an extra milk ejection reflex!

Higher Levels of Prolactin

Prolactin is the hormone responsible for milk production and Zinaman et al in the early 1990’s studied the prolactin responses to infant sucking, hand expression and different types of breast pumps. Each method resulted in a different prolactin response. During double pumping with an electric breastpump, higher prolactin levels were produced. Only prolactin responses to electric pumps compared favorably with the breastfeeding infant.

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