One tool that I recommend every lactation consultant have in their toolbox is a stethoscope. Using a stethoscope will elevate your practice and improve outcomes for the patients you serve. In this post, I will be teaching you the reasons for using a stethoscope, how to evaluate feeding using a stethoscope, and explain what the research has to say about using a stethoscope in breastfeeding evaluation. I’ll also share links to my favorite tools to help you level up your practice.
Cervical auscultation is the technique of assessing milk transfer by listening for swallowing sounds and swallowing-respiratory coordination with a stethoscope placed over baby’s neck. When listening via a stethoscope, normal swallowing will sound like a crisp, biphasic click. Swallowing and breathing can also be clearly distinguished as they have characteristic sounds.
Reasons for Using Cervical Auscultation
Listening for swallowing with a stethoscope can be particularly useful for a nursing newborn in the colostrum phase. Before the mature milk comes in, audible swallowing cannot easily be heard without a stethoscope. Due to the viscosity of colostrum, babies must suck strongly and frequently to generate an adequate bolus for swallowing. Simply observing a feeding may lead to difficulty in confirming actual swallows. Listening with a stethoscope can provide confirmation and help to clarify how baby is feeding.
Once the mature milk has come in, audible swallowing is easier to make out, but it’s not fool proof. Listening for audible swallowing can be difficult in some newborns, in babies with noisy breathing, or if there is a lot of background noise. Listening with a stethoscope in these situations can help confirm the presence of swallowing and also the suck-swallow ratios.
I like to use the stethoscope to help parents connect the dots between the jaw movements they are seeing and when baby is actually swallowing. I’ll either listen and say “swallow” each time I hear a swallow or I’ll let the parent listen and point out when the baby’s jaw excursion suggests swallowing. This goes a long way to help with mom’s breastfeeding self-efficacy. When she gets confirmation that baby is actually swallowing, she becomes more confident in her breastfeeding ability.
How to Listen for Swallowing at the Breast
Using a neonatal or infant stethoscope, place the bell of the stethoscope on baby’s neck or near baby’s temporomandibular joint (TMJ). I prefer using a neonatal stethoscope as the bell is much smaller and easier to fit in the small area of baby’s neck. It can be difficult sometimes to access baby’s neck, though, so placing the bell on baby’s face, close to their ear, will enable you to listen for swallowing, as well, and an infant stethoscope will fit best here.
What the Research Says
While we don’t have much published evidence about using cervical auscultation to assess breastfeeding, cervical auscultation is often used in to evaluate for dysphagia in all age groups. According to Vice et al. (1990), “The feeding and respiratory actions of the pharynx and larynx are associated with characteristic sounds which are audible by stethoscope or microphone held to the skin over the larynx. These acoustical observations reveal aspects of the co-ordination of swallow and adjacent swallow breaths which have not been recognized previously,” (p. 765).
Catherine Watson Genna is a well-respected expert in the lactation field who has written about using cervical auscultation in breastfeeding assessment. According to Watson Genna (2023), “Typically, swallowing has been determined by simply listening externally for soft swallow sounds. This method may miss the more subtle swallows that are not always evident to the naked ear. A more precise method is cervical auscultation. This method uses a neonatal-size stethoscope placed laterally on the baby’s throat to distinctly hear swallowing and breathing sounds,” (p. 163).
Tools I Recommend
As I said above, I prefer a neonatal stethoscope as the bell is fairly small and easier to fit in the small space of baby’s neck. This doesn’t have to be super high quality and is fairly inexpensive. This is a good option from Amazon.
If you cannot find a neonatal stethoscope, an infant stethoscope is the next best choice. I have a Litmann, which is not cheap, but it’s good quality and does the job. It doesn’t work well on newborn necks, but is great for listening at the TMJ on baby’s face. This is the stethoscope I use currently.
References
Genna, C. W. (2023). Supporting sucking skills in breastfeeding infants. Jones & Bartlett learning.
Vice, F. L., Heinz, J. M., Giuriati, G., Hood, M., & Bosma, J. F. (1990). Cervical auscultation of suckle feeding in newborn infants. Developmental Medicine & Child Neurology, 32(9), 760–768. https://doi.org/10.1111/j.1469-8749.1990.tb08479.x
