An ultrasound of the suck cycle can be seen here
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.
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
- Vacuum plays a key role in milk removal
- The tongue does not move in a marked peristaltic motion
- There is no marked indentation of the nipple
- The tip of the nipple does not reach the junction of the hard and soft palate
- Wooldridge infant sucking research 1986 PDF, 34 KB
- Handout "The science of infant sucking" PDF, 667 KB
- Ultrasound presentation for Mac application/zip, 8.02 MB
- Ultrasound presentation for Windows application/zip, 10.67 MB
- Comparison points presentation for Mac application/zip, 4.01 MB
- Comparison points presentation for Windows application/zip, 11.63 MB
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