Response to Preemie Nipple Use with Older Infants?
The unintended consequences of the extended use of preemie flow rate bottle nipples to support breastfeeding
Catherine S. Shaker, MS/CCC-SLP, BCS-S, C/NDT
Neonatal/Pediatric Speech-Language Pathologist
Board Certified Specialist – Swallowing and Swallowing Disorders
www.Shaker4SwallowingandFeeding.com
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After reading the recent post entitled Preemie Nipple Use with Older Infants? The unintended consequences of the extended use of preemie flow rate bottle nipples to support breastfeeding, I felt compelled to respond. Both my clinical experience and the infants I have worked with tell a different story, and the research-base also suggests otherwise.
The original post’s suppositions are worrisome.
A very slow flow nipple the infant must suck harder to pull the milk from the bottle, thereby, strengthening their suck and ensuring bottle feeding is not “easier” than breast.
Use of slow flow nipples for infants who are both breast and bottle-fed is not intended to “strengthen the suck, or ensure bottle-feeding is not easier than the breast.” Breastfeeding is easier because controllable flow rate optimally supports deep and timely breaths. Faster flowing bottle nipples can create “flow rate confusion” with breastfed infants, and that leads to maladaptive sucking to stop/slow the bottle nipple flow (humping the tongue, retracting the tongue, flattening the tongue, using compression-only sucking pattern). These are all adaptive behaviors that breastfed infants will use to “get through” a bottle feeding from a well-intentioned caregiver who provides a rubber nipple whose flow that is faster than the breast flow. These adaptive oral-motor behaviors in response to the after flow can then become learned maladaptations that endure.
Matthew concluded that preterm infants purposefully used significantly lower sucking pressures (changed their suck to compression-only) with high flow bottle nipples, as compared with low flow nipples. This may have been an attempt to manage or “slow” the flow, so they could breathe when necessary.
A study by Eishima described how infants who demonstrated a strong rhythmical suck-swallow-breathe pattern with a regular flow rate nipple changed their sucking pattern to compression-only sucking when the flow was increased. This was hypothesized to be the infant’s purposeful response in attempt to reduce flow, to allow for breathing.
The assumption that a slow flow requires the infant to suck harder, with its obvious adverse effects, has not been proven and is not accurate. The slow flow nipple merely allows less fluid to come out at a time, i.e., a smaller bolus size, so the infant can return to breathing in a timelier fashion.
It is important to note that any nipple ring tightened excessively will create a vacuum that does indeed require “more work”. Just “hand turning” the nipple ring to close it, but not “man turning it,” averts creating a vacuum. This is not nipple-related, it is caregiver related.
Preemie flow rate nipples have been observed to … interfere with self-regulated suck(le)/swallow/breathe sequence. These increase energy expenditure that cause increased fatigue, and in some complex cases, resulting in failure to gain adequate weight or weight loss.
Research indicates that the more controllable flow rate from a premie nipple does not lead to diminished intake. Just the opposite. Paula Meier’s seminal research on flow from the breast versus manmade rubber nipples found that the infant’s ability to control the flow from the breast, i.e. to stop flow by slowing sucking rate and reducing sucking pressure, is what underlies the exquisite physiology of breastfeeding. Supporting breathing, whether at breast or bottle, is the pathway to safe and efficient intake. Indeed, Nyqvist reported that even tiny 29-week PMA infants in Sweden fed small volumes from the breast with physiologic stability. What Meier’s and Nyqvist’ s findings suggest to us is that when the flow is manageable and more controllable, it is ventilatory-sparing and creates opportunities for breathing to occur. When the infant can breathe as needed, physiologic stability is maintained, and this promotes safe and efficient feeding
Research does not support the stated assumption that slow flow nipples cause fatigue, incoordination and weight loss. Lau et al hypothesized that preterm infants would feed more if the flow rate were unrestricted, versus if milk flowed only when the infant was sucking. The study was designed to identify the difference in intake when flow was faster (less controllable) compared to a slower, more manageable “infant-guided” flow rate. Oral feeding performance was documented when milk delivery was “unrestricted”, as routinely administered in nurseries, versus “restricted” when milk flow, which occurred only when the infant was sucking. Proficiency (% volume transferred during first 5 minutes of a feeding/total volume ordered), efficiency (volume transferred per unit time) and overall transfer (% volume transferred) were calculated. Restricted flow rate (i.e., milk flow only with active sucking, such a as a slow flow nipple) enhanced all three parameters. With a slower flow rate, infants were less likely to have to struggle with milk flow when they need to pause to breathe. This is what Goldfield postulates is essential to coordinating swallowing with breathing. The infant’s ability to feed greater volume with a slower flow rate reflects how a manageable flow rate enhances intake. The slow flow promotes the essential respiratory reserves to “go the distance” like marathon runners, as it allows for frequent and deep breaths.
Research shows that flow rate is negatively correlated with feeding efficiency, meaning the faster the flow, the less the intake. Using a randomized controlled trial, Chang and colleagues evaluated the effects of a crosscut nipple (faster flow rate) versus a single-hole nipple (slower flow rate) on feeding. While feeding thin liquids with a crosscut is ill-advised, the cross-cut was studied in comparison to a comparatively slower flowing nipple. Infants were more physiologically stable and used a more efficient sucking pattern with the slower flowing nipple than with the crosscut nipple.
Research by Pados and colleagues looked at effects of milk flow on the physiologic and behavioral responses to feeding in infants with Hypoplastic Left Heart Syndrome. They remind us that feeding is a physiologically stressful event due to the need to coordinate suck-swallow-breathe and maintain adequate oxygenation during the aerobic demands of feeding. During frequent swallows, there is a repeated and prolonged disruption in ventilation during the time the airway is closed for swallowing. A slower flow rate may assist the infant with both maintaining baseline respiratory reserves, as well as the support the timing of the dynamic airway adjustments (opening and closing) that surround the actual swallow. In their study, Pados et al observed physiologic and behavioral responses to a standard flow (Dr. Brown’s level 2) and a slow flow nipple (Dr. Brown’s preemie). Results included the finding that the slower flow allowed the infant to maintain heart rate closest to baseline, and indeed a lower heart rate overall compared to the standard flow rate, suggesting the slow flow feeding was less physiologically stressful, and the infants fed more volume.
Slow flow nipples clearly can be helpful. Because flow rate should be as seamless as possible when infants go from breast to bottle, we always need to look at the bigger picture, and thoughtfully peel apart what is going on and do so in the context of the evidence-base we currently have. This includes our professional wisdom of course, but also the research studies that have helped to change volume-driven practice even with otherwise healthy infants.
References:
Al-Sayed LE, Schrank WI, Thach BT. Ventilatory sparing strategies and swallowing pattern during bottle feeding in human infants. Journal of Applied Physiology 1994 Jul 1;77(1):78-83
Chang YJ, Lin CP, Lin YJ, Lin CH. Effects of single-hole and cross-cut nipple units on feeding efficiency and physiological parameters in premature infants. Journal of Nursing Research 2007 Sep 1;15(3):215-Eishima K. The analysis of sucking behaviour in newborn infants. Early Human Development 1991 Dec 1;27(3):163-73
Gewolb IH, Vice FL. Maturational changes in the rhythms, patterning, and coordination of respiration and swallow during feeding in preterm and term infants. Developmental Medicine & Child Neurology 2006 Jul 1;48(7):589-94
Goldfield EC, Richardson MJ, Lee KG, Margetts S. Coordination of sucking, swallowing, and breathing and oxygen saturation during early infant breast-feeding and bottle-feeding. Pediatric Research 2006 Oct 1;60(4):450-5
Lau C, Smith EO, Schanler RJ. Coordination of suck‐swallow and swallow respiration in preterm infants Acta Paediatrica. 2003 Jun 1;92(6):721-7
Lau C, Sheena HR, Shulman RJ, Schanler RJ. Oral feeding in low birth weight infants. The Journal of Pediatrics 1997 Apr 30;130(4):561-9
Mathew OP. Breathing patterns of preterm infants during bottle feeding: role of milk flow. The Journal of pediatrics. 1991 Dec 31;119(6):960-5.
Meier, P. Suck-breathe patterning during bottle and breast feeding for preterm infants. British Journal of Clinical Practice 1996; 9-20
Nyqvist KH. Early attainment of breastfeeding competence in very preterm infants. Acta Paediatrica 2008 Jun 1;97(6):776-81
Thank you. Agree.
Thank you for this response, Catherine!
Thank you Catherine for sharing I was perplexed by the info in the Peemie Nipple Use article.
YES! Thank you for your thoughtful response, Catherine!
Thank you . This article will be shared with nurses in the NICU…It says very well what I have been trying to convey….
From Allyson Lynne Goodwyn-Craine
Catherine, as always, thank you for your generous and thoughtful response and continued clinical discussion. The original post’s suppositions are worrisome.
A very slow flow nipple the infant must suck harder to pull the milk from the bottle, thereby, strengthening their suck and ensuring bottle feeding is not “easier” than breast.
We are in complete agreement. This is the rationale I frequently hear for the maintaining older infants on preemie flow rate nipples.
As reflected in the research provided the importance of infant driven, self-regulated feeding is key. I am speaking to older infants who are not on standard slow flow nipples but those placed on preemie flow rate nipples that provide roughly ½ the ml per minute flow rate as reflected in the research cited in the original article.
Catherine-in essence, we are saying exactly the same thing but in reverse. As proper flow rate is so clearly indicated for the premature/newborn infant the same holds true for older infants who are not being properly supported with significantly reduced flow rates. I do, in fact, see 3 month old infants who take 45-60 minutes to feed on an ultra or preemie flow rate nipple who do not gain weight either 1) due to energy expenditure or 2) who experience such high fatigue that they fail to consistently complete their bottles. This is very easily corrected by bringing them off preemie flow and introducing to a standard, slow flow nipple
Do you hear popping sounds as the infant sucks, see cheeks pulling deeply inward or over use of the jaw as they suck on the preemie nipple? Although often assumed a characteristic of tongue tie, a popping, clicking or snapback sound is often heard with bottle feeding when the flow rate is too slow when the infant increases inner oral pressure by dropping the jaw too far down (over use of compression) which, breaks the seal between the posterior tongue and hard palate.
I’m an RN and I’ve worked in NICU for 25 years and am convinced that finding a comfortable, manageable flow rate should be an individualized affair. So may people use the statement of “that hasn’t been proven ” to justify their opinion on a subject i.e. “The assumption that a slow flow requires the infant to suck harder, with its obvious adverse effects, has not been proven and is not accurate. “. Just because no studies have been drawn does not allow you to draw any conclusions and is disingenuous . Common sense and observational evidence should put the latter part of that statement to rest. If a patients ability to safely consume milk exceeds the flow rate of a given nipple (and they vary widely) adjustments should be made.