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 officially stimulated, they switch to a slower and deeper suck for the actual feeding phase: To get as much milk as possible.

Knowing that current breast pumps 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, imtitating the baby's natural nursing rhythm. For this reason, Medela initiated a study into the phsiology 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 breast pumps 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 named expression.

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 breast pumps.

2-phase Expression is...

Proven to feel most like 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)

  • 5 minutes with the Symphony Expression Phase can remove as much as an average 16 minute breastfeed (3)
  • When used at Maximum Comfort Vacuum, 80% of expressed milk is removed in the first 7 minutes (5)

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 1/2 minutes (6)
  • Low frequency pattern approx 2 1/2 minutes (2)

With the introduction of 2-Phase Expression, Medela took a bold step towards modern breastpump technology and introduced the hospital grade Symphony breastpump in 2002. 2-Phase Expression is now available in four personal use breast pumps.

To complete the circle and assist in feeding the expressed milk to the baby, Medela has further developed the research and designed Calma. A unique feeding system which encourages the baby to pause and breathe regularly, thereby maintaining their naturally learned feeding behaviour. Pioneered to benefit the mother and baby's unique breastfeeding bond.

Useful products
  1. Pediatrics 113 (2) 2004 
    "Ultrasound Imaging of Milk Ejection in the Breast of Lactating Women" 
    Donna T. Ramsay, Dip; Jacqueline C. Kent, PhD; Robyn A. Owens, PhD; and Peter E. Hartmann, PhD
  2. Journal of Human Lactation 19(2) 2003 
    "Response of Breasts to Different Stimulation Patterns of an Electric Breast Pump" 
    Jacqueline C. Kent, BSc, PhD; Donna T. Ramsay, DMU, PGDip; 
    Dorota A. Doherty, PhD; Michael Larsson, MBA; 
    Peter E. Hartmann, BRurSci, PhD
  3. Journal of Human Lactation 18(4) 2002 
    "Effect of Vacuum Profile on Breast Milk Expression Using an Electric Breast Pump" 
    Leon R. Mitoulas, PhD; ChingTat Lai, MSc; Lyle C. Gurrin, PhD; 
    Michael Larsson, MBA; Peter E. Hartmann, PhD
  4. Midwifery 2 (4) 1986
    "The 'Anatomy'of Infant Sucking" 
    Michael W. Woolrigde
  5. Breastfeeding Medicine 3 (1) 2008 
    "Importance of Vacuum for Breastmilk Expression" 
    Jacqueline C. Kent, Leon R. Mitoulas, Mark D. Cregan; 
    Donna T Geddes, Michael Larsson, Dorota A. Doherty and Peter E. Hartmann
  6. Presented at 12th ISRHML Conference, Cambridge 2004 
    Milk Flow Rates Can Be Used to Identify and Investigate Milk Ejection 
    in Women Expressing Breast Milk Using an Electric Breast Pump" 
    Donna T. Ramsay; Leon R. Mitoulas; Jacqueline C. Kent; Mark D. Cregan; 
    Dorota A. Doherty; Michael Larsson; and Peter E. Hartmann

Further reading:

Wolff PH. The serial organisation of sucking in the young infant. Paediatrics.1968;42: 943-966

Continuing research is paramount in supporting mothers and babies to continue to breastfeed for as long as possible. Medela group exits to enhance the health of both mother and baby, through the life giving benefits of breastmilk and we will continue to do research to provide up to date information for health professionals who support breastfeeding mothers.

Our annual research symposiums are an opportunity to bring the experts into the field and for you, as a professional to learn directly from them in order to continually improve your practice.