2-Phase Expression

Breastfeeding is one of the most beautiful and natural experiences a mother can share with her baby. It is a unique time when mother and baby feel intensely close and intimate. Breastfeeding is also practical since the milk is always available at the right temperature, whenever the baby gets hungry. Moreover, breastfeeding benefits the health of both mother and baby in many different ways.

Nature made babies very efficient. They instinctively know how to get their mother's milk by changing the way they suckle at the breast during breastfeeding.


Studies have shown that babies naturally nurse in 2 phases

  1. Initially they suckle fast and light: To stimulate the milk ejection reflex (MER) and to start the milk flowing
  2. Once the breast has been sufficiently stimulated, they switch to a slower and deeper suck for the actual feeding phase: To get as much milk as quickly as possible


Babies naturally nurse in 2 phases more

Knowing that current breastpumps are based on a study by Einar Egnell dating back to the 1950s, Medela's goal was to provide new scientific evidence for modern breastpump design. In the late 1990s, Medela's vision was to produce the most comfortable and efficient breastpump ever, imitating the baby's natural nursing rhythm. For this reason, Medela initiated a study into the physiology of a baby's natural sucking behaviour and also began to evaluate current electric breastpump function.

With Professor Peter Hartmann and his team, an ideal partnership was formed to conduct this research project at the Biochemistry Department of the University of Western Australia in Perth, Australia. Peter Hartmann is an internationally renowned specialist for his studies in the fields of breastfeeding and milk synthesis. In the course of 2002, Professor Hartmann's breakthrough research findings resulted in the development of an exclusive pumping pattern called 2-Phase Expression which closely mimics a baby's natural nursing rhythm.

The revolutionary 2-Phase Expression technology consists of:

  • Stimulation mode (for rapid stimulation of the milk ejection reflex)
  • Expression mode (for gentle and efficient expression)

Similar to a nursing baby, 2-Phase breastpumps mimic a baby's natural sucking behaviour

First, a fast pumping rhythm to stimulate the milk ejection reflex and to start the milk flowing. This phase is named stimulation. Then, a slower pumping rhythm to express milk gently and efficiently. This phase is namedexpression.

Through intensive and pioneering work, Medela has converted the baby's intuitive knowledge into technological know-how. The result is 2-Phase Expression - the new standard for unsurpassed naturalness, comfort and efficiency in breastpumps.


2-Phase Expression is

Proven to feel most like a baby

High frequency patterns have been rated by mothers as feeling most like a baby (minimum 100 cycles per minute/similar to a baby's non-nutritive sucking of about 2 sucks per second) 2, 4

Proven to get more milk in less time (when pumping at Maximum Comfort Vacuum in the Expression Phase (please see page Good to know / Correct pumping))

  • 5 minutes with the Symphony Expression Phase can remove as much milk as an average 16 minute breastfeed3
  • When used at Maximum Comfort Vacuum, 80% of expressed milk is removed in the first 7 minutes5

Proven to achieve faster milk ejection and faster milk flow

Time to reach milk ejection:

  • Baby approx. 1 minute 1
  • High frequency pattern (Symphony) 1