Since the 1970’s it has been reported that a deviant suck in preterm infants or sick term infants was a sign of neurological issues. This oral motor dysfunction was an early indicator of neurological abnormalities. Sucking patterns of full-term newborns and preterm infants in the NICU have been identified and described as being different depending upon their gestational age and early development.
The suck pattern of the preterm infant has been described as an immature suck pattern characterized by short sucking bursts of 3-5 sucks followed by a pause of equal duration during which the infant breathes and/or swallows. If the nipple is a faster flow or the infant has a stronger suction component the swallow may occur after every suck. But if the nipple is a slower flow and/or the infant has a weaker intra-oral suction component, then he/she may suck three times and the swallow may occur during the pause.
The suck pattern of the term infant is quite different because the full-term infant has the respiratory support and neurological maturation to coordinate continuous sucking bursts in which the suck/swallow/breathe all occur inside the burst, usually at the average rate of 1/1/1/ in one second. This pattern has been described as having over 10 sucks per burst. Some infants may suck up to and perhaps beyond 60 sucks in one burst. This pattern is also referred to as a mature suck pattern.
Since an infant’s suck is as “individual as his fingerprint” once said by Dr. James Bosma, we expect that the infant with a normal immature or mature suck pattern will be able to maintain that rhythmical pattern for at least two minutes. This is the observation time required for the completion of an accurate assessment of the suck pattern using the NOMAS (Neonatal Oral-Motor Assessment Scale).
When an infant has a medical issue, is younger than 36 weeks post-conceptional age, or has respiratory challenges he/she may present with a disorganized suck pattern. This has been defined by “a lack of rhythm of the total sucking activity” (Crook, 1979) which refers to the suck, swallow, and breathing.
Three separate presentations of the disorganized suck have been identified and described. These include the infant who is not able to maintain a sufficient number of sucks per burst to stay within the mature suck pattern. Such an infant may begin the feeding with sucking bursts that are over 10 sucks per burst but then soon the bursts decrease to below 10 and as the bursts become shorter the pauses become longer and often are accompanied by signs of labored respiration.
Another example of a disorganized suck pattern has been described as the Transitional pattern. In this pattern, the infant demonstrates sucking bursts that have 6, 7, 8, or 9 sucks in most of the bursts. Since the transitional pattern is a burst-pause pattern in which the breathing does not occur during the burst the infant may experience oxygen desaturation or deglutition apnea.
Finally, the third presentation of the disorganized suck occurs in the full-term infant who is not able to maintain ta consistent suck/’swallow/breath ratio for two minutes.
Some infants present with oral dysfunction that can be diagnosed on the NOMAS and the movements of the jaw and tongue can be clearly described. These infants generally have either hypertonicity or hypotonicity of the oral facial area that impacts the quality of the oral movement during sucking. Oral-facial hypertonicity may result in jaw clenching and tongue retraction while hypotonicity may result in excessively wide excursions of the jaw and a flaccid tongue that is not able to maintain the intra-oral seal on the nipple. In both cases the suction component is poor and the infant will require compensatory therapeutic strategies in order to improve their oral feeding abilities.
Follow-up studies that looked at these infants have reported that when an infant presents with a disorganized suck and stress as based on the NOMAS it takes them 22 days longer to transition to full oral feedings than those infants who present with a disorganized suck, as many preterm infants do, but who do not have clinical signs of stress.
Follow-up studies that looked at those infants in the NICU who presented with oral dysfunction and a dysfunctional suck, based on the NOMAS, reported that there was a developmental delay in one or more areas of developmental at 24 months of age.
Early diagnosis of the infant suck pattern is important, not just so that early therapeutic intervention may be prescribed in order to help the infant to be more competent with oral feeds, but also to serve as a predictor of later developmental outcomes. Being able to assist the family with their infant at discharge from the NICU by discussing the infant’s suck pattern and the possible developmental outcome may be the role of the NICU Nurse, Speech and Language Pathologist, and/or Occupational Therapist. A referral to a community Early Intervention Program and/or Physical Therapy and Feeding Specialist may be indicated.
Marjorie Meyer Palmer MA, NLP, CCC-SLP, Neonatal / Pediatric Feeding Specialist, Speech-Language Pathologist, Founder / Director NOMAS® International
Download the full articles in PDF:
Predictability of Neonatal Sucking for Later Developmental Outcomes
Developmental Outcome for Neonates with Dysfunctional and Disorganized Sucking Patterns
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