Can newborns breathe and swallow at the same time?

You enter an exam room and see a mother and her newborn. The mother, a professional singer, is very concerned because she has noticed that her baby repeatedly stops suckling to breathe during breastfeeding. Why, the mother asks, is her baby not breathing and suckling at the same time? She is so concerned that she is contemplating switching to bottle-feeding. You ask her why would she not expect her baby to breathe noticeably when breastfeeding. She immediately takes the recently published book on the human voice,This is the Voice, by John Colapinto,¹ which she read book prior to giving birth out of her purse and points to page 42: “Instead [relative to adults], the newborn larynx is crowded up into the back of the mouth, close to the opening of the velum. This aids breastfeeding by creating an uninterrupted airway from nose to lungs (so newborns can suck at mom’s breast without having to suck and “come up for air” as they feed – the milk flowing around the sides of the raised larynx and into the stomach).” Further, she takes out her cell phone and starts showing you numerous websites that report the same phenomenon.² She then shows you a short YouTube video devoted to this topic.³ Lastly, she shows you a printed version of a review of the book that appeared in the New York Times on February 10, 2021⁴ by well-known nonfiction author, Mary Roach, that states, “This [the high larynx] makes possible nonstop suckling; unlike adults, babies can swallow and breathe at the same time.” She also tells you that she has read many of Roach’s books and thus believes that if Roach mentioned it in the book review, it “must” be true. 

Of course, now, after you reassure this mother, your curiosity is aroused. Is there any truth to this concept? If so, what is the underlying anatomy and physiology that facilitates it?

Figure 1. Drawing by Dr. Crelin reproduced with permission from Laitman et al. (1977)⁵. Note the depiction of the hypothesized contact (interlocking) of the soft palate (1) and the epiglottis (2). It is interesting that in Crelin’s earlier Atlas (1969, plate 114)¹, he does not show this apposition of the epiglottis and uvula.

The concept that newborns can breathe and swallow simultaneously has no merit – it is absolutely false. Any speech/language pathologist (SLP) or occupational therapist (OT) who treats newborn dysphagia, when watching a newborn suckle, specifically looks for a normal suck/swallow/breathe pattern, generally 1-3 sucks to every breath. 

Nevertheless, as suggested by its presence in many sources, albeit unreliable ones, this simultaneous breathing/swallowing concept is entrenched in the popular literature and is even present in a chapter on pediatric anatomy in a 2019 textbook, Pediatric Surgery.⁵ So, what is the history of this idea?

Figure 2. Sequential images from cineradiological recordings showing the movement of the pharyngeal/laryngeal structures during newborn infant swallowing. Used with permission from Bosma et al. (1966).11 Note that in these images the epiglottis is shown to partially cover the entrance to the larynx as it does in adults, and not to interlock with the soft palate. 

The concept that infants can swallow and breathe at the same time has a long history dating back to the 19th century; this early history was summarized by Peiper in 1963,⁶ who supported the assertion. However, its most definitive and ardent supporters, based primarily on the high relative position of the infant larynx (Figure 1) compared to adults, was Edmund Crelin, PhD, DSc, articulated most definitively in his 1973 book, Functional Anatomy of the Newborn,⁷ and his student, Jeffrey T. Laitman, PhD. In the 1973 book Crelin stated, “the elevation of the larynx [in newborns] also directs the opening of the larynx into the nasopharynx so that the infant can breathe freely while fluid is passing into its pharynx.”⁷

In a subsequent 1977 article, Laitman, Crelin, and Gerald Conlogue8 dismiss 9 earlier studies that did not observe this phenomenon: “Studies by Ardran et al, and Bosma et al using cineradiography to study young human infants swallowing barium [Figure 2] in water and milk, did not describe the interlocking [our italics] of the larynx and pharynx.”⁸

Dr. Crelin died in 2004 but Laitman and colleagues continued to advocate for this concept, albeit with less certainty, as time passed. For example, in 1993,⁹ Joy S. Reidenberg, PhD, and Laitman stated:

“High laryngeal position in newborns and young infants will enable the existence of largely separate respiratory and digestive pathways similar to those described in other terrestrial mammals. These essentially separate pathways prevent the mixing of most ingested food and inhaled air. These routes may also enable the baby to breathe and swallow some liquids almost simultaneously in a manner similar to that shown in nonhuman primates.”⁹

Laitman continues to support the concept in this tentative manner in print until at least 2017,¹⁰ despite masses of evidence that it was not true:

 “These essentially separate pathways prevent the mixing of most ingested food and inhaled air. These routes may enable the baby to breathe and swallow some liquids almost simultaneously in a manner similar to non-human primates.”¹⁰

Apparently, Crelin and Laitman were unaware of an earlier study by Thomas George Wilson, FRCSI, FRCSE, FRCS, FACS, FRSM, MRIA, HRHA, from 1952¹¹ demonstrating the significant variability in the shape of the newborn larynx. This variability would preclude any certainly in the hypothesized “locking” of the epiglottis and soft palate during swallowing. Further, Wilson also stated that the tissues of the newborn larynx are softer and thus more pliable than those in the adult, suggesting that the epiglottis would not be able to interlock with the soft palate in any way that would form a sealed channel.

A much more recent study¹² also described the greater softness of the newborn epiglottis compared to that of the adult. Further, this study also noted that children with an especially high epiglottis, who may complain of a foreign body in their throat, in most cases, pose no reason for concern as a high epiglottis can simply be a normal anatomical variant. Of course, this raises the possibility that some of the newborn cadavers examined by Crelin happened to have this variant. 

In 1981, Wilson SL¹³ specifically addressed the issue as to whether infants can swallow and breathe simultaneously using instrumented measurement on preterm infants and concluded, “In contrast to this [Crelin/Laitman] view, we found a consistent interruption of respiratory flow associated with spontaneous nonfeeding swallows. Although we have no data on swallowing associated with feeding, we found no basic difference between the mechanism of nonfeeding swallows in these infants and that described in adult man for the swallow of a bolus.”¹³

Above we presented a scenario in which the ubiquity of the simultaneous swallow/breathe concept might take physician and/or therapist time, and have a financial cost to the newborn’s family (the cost of the office visit); in addition, this concept might cause disruption of breastfeeding, and undue anxiety in the patient’s family. 

Another example of the possible unintended consequences of the simultaneous breathe/swallow theory relates to OT and SLP students. These students are taught correct information on infant suckling in their courses but when they do their inevitable internet searches they will find significantly different information. This discrepancy would then likely be called attention to in class or privately with the instructor. This scenario occurred to one of us and eventually led to the writing of this essay.

The idea that babies can breathe and swallow at the same time joins a very long list of incorrect/dangerous notions developed, often by pediatricians, on the care of the newborn. One such notion noted in an article in Slate on this topic15 was that babies, regardless of age, should not be fed at night because this overindulgence could contribute to the development of socialism. Another, by the same pediatrician, was that babies should be started on cereal at 2 days of age because breastmilk and formula are deficient. 

The current widespread presence of the simultaneous breathing/swallowing theory in a popular book and the internet is striking especially considering that Laitman’s support for this theory is clearly waning. In this article we are hopefully starting on the road to change a mindset, and we realize that changing a “mindset” does not happen readily or quickly. Further, we know that in trying to change this mindset we may only be “tilting at windmills.” However, if one doesn’t try, the mindset will never change.

References

1. Colapinto, J. This is the Voice. Simon and Schuster, New York: 2021.

2. Livescience. https://www.livescience.com/7468-hyoid-bone-changed-history.html; Dental Sleep Practice. https://dentalsleeppractice.com/ce-articles/evolution-human-oral-airway-apnea/; Brian Palmer, DDS. https://www.brianpalmerdds.com/ All accessed August 10, 2021.

3. Youtube. Accessed August 10, 2021. https://www.youtube.com/watch?v=4R639t1da6I

4. New York Times. Accessed August 10, 2021. https://www.nytimes.com/2021/02/10/books/review/this-is-the-voice-john-colapinto.html

5. Stringer M. Anatomy of the infant and child. In: Puri P, Hollwarth M, eds. Pediatric Surgery. Spinger-Verlag; Berlin; 2019: 83-101.

6. Peiper A. Cerebral function in infancy and childhood. Consultants Bureau. New York: 1963.

7. Crelin, ES. Functional anatomy of the newborn. Yale University Press. New Haven: 1973. 

8. Laitman, JT, Crelin ES. Conlogue GJ. 1977. The function of the epiglottis in monkey and man. The Yale Journal of Biology and Medicine. 1977; 50: 43-48.

9. Laitman JT, Reidenberg J. Specialization of the human upper respiratory and upper digestive systems as seen through comparative and developmental anatomy. Dysphagia. 1993; 8:318-325. doi: 10.1007/BF01321770

10. Laitman, JT, Noden DM, Van der Water TR. Formation of the larynx: From Hox genes to critical periods. In: Sataloff RT, ed. Voice Science. Plural Publishing; San Diego; 2017: 13-30.

11. Wilson TG. Stridor in infancy. The Journal of laryngology and otology. 1952; 66:437-451. doi:10.1017/s0022215100047903

12. Petkar N, Georgalas C, Bhattacharyya A. JABFM. 2007; 20:495-7. doi: 10.3122/jabfm.2007.05.060212

13. Wilson SL, Thach BT, Brouillette, Abu-Asaba. Coordination of breathing and swallowing in human infants. J Appl Physiol Respir Environ Exerc Physiol. 1981;50: 851-858. doi:10.1152/jappl.1981.50.4.851

14. Crelin ES. Anatomy of the newborn: An atlas. Lea and Febiger. Philadelphia: 1969.

15. Slate. Accessed August 10, 2021. https://slate.com/human-interest/2012/11/bad-baby-advice-a-history.html)

16. Bosma JF, Truby HM, Lind J. Cry motions of the newborn infant. Acta Paed Scand. 1966; 49: (Suppl 61): 62-92.