Question & Answer - Feeding, Eating, & Drinking

How can flow rate impact infant feeding, and what can stress cues tell you about this?

For infants, the act of eating is one of the truest definitions of second nature. It is a very intricate process that, on occasion, may be a struggle. Parents of infants who experience feeding difficulties can find support working with a Speech-Language Pathologist or Occupational Therapist with advanced, specialized training in pediatric feeding. Breast feeding support is also provided by Lactation Specialists. For the purpose of this discussion, however, we will focus on one of the most common feeding issues which can create stress during feeding for infants (i.e., flow rate).

Breast flow rates are variable and, most often, under optimal control of the infant. During milk let down, the rate and volume of the breast milk flow are slightly faster than after milk let down. During this phase, the infant may come off the breast, appear startled, or cough as he or she learns to handle the increased flow rate. However, most babies overcome these difficulties and complete the feeding without distress.

Bottle flow rates are constant, less dynamic than the breast. Most manufacturers rank flow rates numerically (Level 1, 2, 3, etc.) or descriptively (slow, medium, fast). Bottle nipple flow rates influence the amount of liquid entering the infant’s mouth with each suck. This determines the speed at which the infant needs to swallow.

Optimal feeding occurs when the infant is relaxed and calm, as well as eating with lots of lovely eye contact and occasional cooing sounds. Some infants are more vocal than others during feeding, but all should be engaged with their feeders. When possible, set you iPhone and other distractions aside and enjoy a feeding conversion with your precious little one.

Infants suck 1-2 times, swallow, breathe, and repeat at a relaxed pace. Periodically they hold the nipple still in their mouths while they breathe through their noses to catch their breath. These catch up breaths are like putting gas in a car, oxygen provides the energy for the infant to continue eating.

When these delicate, synchronous movements are pressured, the infant responds accordingly. If milk flows too quickly through the nipple, the infant is compelled to swallow at a quicker pace and that can make it difficult for him or her to catch their breath. These conditions make feeding a strenuous and exhausting activity. Imagine running a race and being handed a cup of water to drink every few feet. It would be very difficult drink while you exert yourself. Either your endurance would decrease, or you would likely have water going down the wrong pipe as you struggle to coordinate your repeated swallows with breathing.

Common stress cues can tell you a baby is struggling during breast or bottle feeding:

-Cough; wet, gurgle throat sounds; gulping sounds; or throat clearing (air pushed between their vocal cords without using their voice). These are signs that liquid is going near or down the wrong pipe, meaning liquid is heading toward the lungs and not the stomach.

These cues are particularly important for babies under three-months of age. Their tiny little neck structures are so close together they provide extra protection around the airway. So, if liquid is making its way toward the airway it is not normal or safe.  

At around three-months, the neck gets longer as the baby grows and more space is created in and around the airway requiring increased coordination when feeding and swallowing. An occasional cough is ok, but, again, the three+ month-old baby should not have sounds other than gentle cooing coming from his or her throat when feeding and swallowing.

-Furrowed brow, wide eyes, redness around brow/eyelids, and watery eyes when feeding are also signs of stress.

-Tension in the legs/arms and/or clenched fists often held high near the face are body clues that a baby is struggling. Infants should be relaxed and calm without body tension when feeding.

-Clenched jaw, tight lips, and/or dimples/tension on the outside edge of the lips are signs your infant is using his or her mouth to slow the flow rate of the nipple. Infants’ lips should be relaxed. It can be normal for the upper lip to tuck under (invert) when breast feeding. However, with a bottle, the pink of the upper lip should be seen (i.e., think fish lips).

-If a bottle is completed too quickly, this means the infant’s stomach may be filling too quickly which may lead to reflux. Newborns and infants under 4-months of age should take 20-30 minutes to complete a bottle. Feeding should take some time. In fact, if the infant is completing a bottle faster than in 20 minutes, you likely need a slower flow nipple. There is a lot of good information on the use of slow flow nipples and paced bottle feeding.

-Protests! Infants will do what they need to do to feel safe. So if the nipple flow is too fast, it is common for them to reject it often by turning away, clamping their mouths shut, and sometimes, even pushing or batting the bottle away. Side note: Reflux is common and can be painful for some babies. Rejecting the bottle in response to reflux often involves arching their backs and expressing a pain cry. If this happens contact the pediatrician.

-Infant is initially alert, but very quickly moves into sleep. What can look like sleep early on in the feeding may actually be shut down. Infants who are overstimulated or stressed will slip into this state as a means of stopping the activity. Shut down typically occurs during the early phase of feeding as a stress cue. It is normal for newborns to require re-alerting during feeding and for older infants to become dozy or fall asleep during feeding, but shut down is not normal.

-Limited weight gain. Infants expend a good deal of energy in the act of feeding. Sometimes flow rate of the nipple can force the infant to eat too fast or too slow. When flow rate is too fast infants may protest/reject the bottle, show other stress signs, and possibly vomit if too much liquid enters the stomach too fast. When feeding takes more than 30 minutes the flow rate may be too slow. Infants burn more energy than they eat after 30 minutes total feeding time with bottle feedings.

-There are a few more very subtle signs a feeding specialist may attend to, particularly for infants who are/were in the NICU (Neonatal Intensive Care Unit) or who are medically fragile. However, that is beyond the scope of this discussion. If you see other signs about which you are concerned, discuss these with your pediatrician.

When a baby demonstrates any of these stress cues, with exception of feeding times over 30 minutes, the first step is to slow the nipple flow rate. With a baby at the breast, this can be accomplished by positioning mom in recline with the baby on his or her tummy at the breast (i.e., the laid-back position). This allows the milk to come forward against gravity or spill out of the mouth if still too fast, particularly during milk let down. If the first let down is consistently the point at which the infant struggles, pumping through the first let down before bringing baby to breast can help. If you are bottle feeding, be sure to begin feeding with a slow flow nipple. Bottle nipple manufacturers who use numeric rating systems typically associate them with chronological age ranges to help you know where to start.  However, each infant is unique, so you may need to find the bottle nipple that suits your baby.

Infants communicate a great deal of helpful information during feeding when we carefully observe and understand their meaning. Simple adjustment with flow rate can make a big difference for many babies. You can also find additional help from a lactation or feeding specialist if additional support is needed.

About Allyson Goodwyn-Craine (allysoncraine@comcast.net)

Allyson Goodwyn-Craine (Ally) began her career in 1989. She is a Neuro-Developmental Treatment (NDT) trained Pediatric Speech-Language Pathologist/Feeding Specialist who has worked in Private Practice, Shriner’s Children’s Hospital, Randall Children’s Hospital, and now at Kaiser Sunnyside Medical Center. Ally enjoys helping medically complex babies and toddlers who struggle with feeding challenges from breast, bottle, and tube feedings to transitioning to solid foods. Ally joins infants, toddlers, and their parents in the NICU, NICU Follow-Up Clinic, outpatient treatment, and as a member of the Cleft Palate team.

Allyson served as the Clinical Program Director then as the Executive Director of the Artz Center for Developmental Health and Audiology, formerly the Hearing and Speech Institute. During her tenure as Executive Director, the Institute was recognized in the Top 100 Best Non-Profits for which to Work by Oregon Business Magazine and was ranked in the Top 20 Healthcare Non-Profits in Oregon by the Portland Business Journal. Allyson served on the Financial Planning Board of the American Speech-Language-Hearing Association. She is a past president of the Oregon Speech-Language-Hearing Association. She has served on the advisory board and as an adjunct professor at Portland State University for 19 years and is a guest lecturer in Pacific University and University of Oregon graduate programs. She has also traveled nationally and taught as a member of the Education Resources clinical faculty. Allyson was recently awarded the Honors of the Association by the Oregon Speech-Language-Hearing Association.