The science of infant sucking

Successful breastfeeding is an interplay between mother and baby. In order to understand and manage infant sucking issues, it is firstly important to establish an understanding of the anatomy and physiology of lactation and milk removal. Medela, along with leading experts from The University of Western Australia, examined the anatomy of the lactating breast (Ramsay et al. 2005). This groundbreaking research challenged previous understandings and led to many text books being rewritten. This new knowledge was then applied to how the infant removes milk from the breast.

Suck cycle

The suck cycle

The University of Western Australia combined the use of ultrasound and vacuum measurements to investigate infant sucking during breastfeeding.

During a suck cycle vacuum begins at the baseline, increases as the tongue lowers, and reaches a maximum when the tongue is at the lowest point. As the tongue lowers, milk begins to flow. The tongue then rises and comes to rest again at the baseline – and the milk stops flowing.

Key findings

Key findings

  1. Vacuum plays a key role in milk removal
  2. The tongue does not move in a marked peristaltic motion
  3. There is no marked indentation of the nipple
  4. The tip of the nipple does not reach the junction of the hard and soft palate
Ultrasound video

An ultrasound of the suck cycle can be seen here

It plays in slow motion here so the action of the action of the tongue can be seen.

An overlay has been place of this image to enhance understanding.

Study abstracts
Study abstracts
Anatomy of the lactating human breast redefined with ultrasound imaging

The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast. The breasts of 21 fully lactating women ...

Ramsay DT, Kent JC, Hartmann RA and Hartmann PE (2005)

Journal of Anatomy 206, 525-534
Tongue movement and intra-oral vacuum in breastfeeding infants

The mechanism by which the breastfeeding infant removes milk from the breast is still controversial. It is unclear whether the infant uses predominantly intra-oral vacuum ...

Geddes, D.T., Kent, J.C., Mitoulas, L.R. and Hartmann, P.E. (2008)

Early Human Development 84: 471-477
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Breastfeeding attachment

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Kent, J.C., Mitoulas, L.R., Cregan, M.D., Geddes, D.T., Larsson, M., Doherty, D.A. and Hartmann, P.E. Importance of vacuum for breastmilk expression. Breastfeeding Medicine 3(1): 11 - 19 (2008)

Geddes, D.T., Langton, D.B., Gollow, I., Jacobs, L.A., Hartmann, P.E. and Simmer, K. Frenulotomy for breastfeeding infants with ankyloglossia: Effect on milk removal and sucking mechanism as imaged by ultrasound. Pediatrics 122: e188 - e194 (2008)

McClellan, H.L, Geddes, D.T., Kent, J.C., Garbin, C.P., Mitoulas, L.R. and Hartmann, P.E. Infants of mothers with persistent nipple pain exert strong sucking vacuums. Acta Paediatrica (2008)

Woolridge, M.W. The anatomy of infant sucking: Midwifery Dec; 2(4): 164-71 (1986)sucking baby on mothers breast