Quantifying Neonatal Sucking Performance: Promise of New Methods

A Unique Clinical Tool for the Evaluation of Oral Feeding Skills in Infants

Background. Occupational therapy practice for oral feeding assessment is based on clinical observation of infants' sucking, swallowing, and breathing ability, which is influenced by clinical experience and provides poor evidence on explanatory factors. Purpose. To test the clinical utility and safety of a nipple monitoring device for the quantitative evaluation of oral feeding skills. Method. Sixteen infants, with no severe medical complications, participated in a pre-experimental pilot study. Oral feeding performances (duration, intake volume, and rate of transfer), and occurrence of adverse events (apnea, bradycardia, and oxygen desaturations) were recorded to ensure the tool does not interfere with infant's feeding ability or does not create any adverse effects. Findings. There was no significant difference in duration, intake volume, rate of transfer between the two monitored sessions, and no occurrence in adverse events. Implications. The findings suggest that the nipple monitoring device may be used for quantitative assessment and intervention planning of oral feeding difficulties in infants.

Early feeding behaviours of extremely preterm infants predict neurodevelopmental outcomes

BACKGROUND

Infants born extremely preterm are at high risk for early feeding difficulties, as well as poor neurodevelopmental outcomes in childhood. Feeding, a complex motor skill, may be predictive of later neuromotor outcomes.

AIMS

To determine the relationship between feeding behaviours of extremely preterm-born infants (<28 weeks gestational age) at 4-months corrected age (CA) and neurodevelopmental outcomes at 4-5 years.

STUDY DESIGN

Retrospective cohort design with prospectively collected data.

SUBJECTS

Infants born extremely preterm from September 1999 - October 2013 [n = 412, mean gestational age 25.4 (1.3) weeks; mean birth weight 771 (168) grams]. Oral feeding was assessed at 4-months CA by an experienced occupational therapist; infants were classified as either having poor suck-swallow ('feeding difficulties') or no feeding difficulties.

OUTCOME MEASURES

Motor outcomes were assessed at 4-5 years using the Movement Assessment Battery for Children (MABC). Children were categorized as: (1) typical motor development (TMD; n = 214); (2) Developmental Coordination Disorder (DCD; n = 116); or (3) major neurodevelopmental disorder (MND; n = 82).

RESULTS

Feeding behaviour at 4-months CA predicted DCD (OR = 2.95, CI 1.13-7.68) and MND (OR = 3.67, CI 1.35-9.96) after controlling for confounders. Infants with feeding difficulties were more likely to be diagnosed with DCD (40 % of poor feeders) or MND (36 %) at 4-5 years, compared to infants without feeding issues.

CONCLUSIONS

Early feeding behaviours significantly predicted motor outcomes at 4-5 years. Infants born extremely preterm with early feeding difficulties should be identified as at high risk for poor motor outcomes later in childhood and screened for early diagnosis and intervention.

Infant stimulation reduces weight loss and increases breastfeeding: a randomized controlled trial

OBJECTIVES

The study aimed to measure the effect of auditory, tactile, visual, and vestibular (ATVV) stimulation therapy on sucking effectiveness (SE), infant-feeding mode, weight, height, and head circumference (HC) of full-term infants.

METHODS

A single-blinded randomized trial with a sample of 107 mother-child dyads. Inclusion criteria were healthy first-time mothers and full-term infants with no known pathological conditions, weighing between 2500 and 4000 grams, and recommendation of exclusive or predominant breastfeeding. The mothers in the experimental group (EG) received training in ATVV stimulation therapy and provided it from birth (first 24 hours of life) until the end of the follow-ups at week 5. The control group (CG) received only standard care that included education on warning signs and basic guidance on breastfeeding. SE, infant-feeding mode, and neonatal growth were measured at weeks 2 and 5.

RESULTS

In contrast to CG infants, the EG infants drank 2.02 cc more human milk in one minute of effective breastfeeding (p=0.002) at week 2 and 5.51 cc more at week 5 (p<0.0001). They showed greater adherence to breastfeeding at week 5 (p=0.025) and gained more weight: 8.35 grams/day (p=0.009) and 4.19 grams/day (p=0.008). HC did not differ between groups, and height difference was statistically significant at week 5 (p=0.025).

CONCLUSIONS

ATVV stimulation therapy has a positive effect on neonatal health as it promotes effective sucking and exclusive breastfeeding, reduces weight loss, and improves neonatal growth.

Artificial Neural Network for Identification of Infant Feeding Tracking Using the Smart Bottle System

In this work, we present the results of a comparison of simple artificial neural network (FFNN) designs intended to identify infant bottle-feeding events and appropriate feeding volume recording intervals using accelerometer data recorded from a custom designed "Smart Bottle" system. To properly identify and distinguish these events with an accuracy of 99.8%, while accommodating the constraints of the deployment environment, two concurrent FFNNs were implemented.

Impact of umbilical cord arterial pH, gestational age, and birth weight on neurodevelopmental outcomes for preterm neonates

Background

The aim of this study was to determine the impact of umbilical cord arterial pH, gestational age, and birth weight on neurodevelopmental outcomes for preterm neonates.

Methods

We examined 112 neonates. Inclusion criteria were: Saturations greater than 88%, and heart rates between 100–205 beats per minute.

Measurements

We assessed several neurodevelopmental factors as part of the Brazelton Neonatal Behavioral Assessment Scale (NBAS), 4th edition, such as asymmetric tonic neck reflex (ATNR), motor maturity, response to sensory stimuli, habituation, and state regulation. Initial assessment parameters such as APGAR score and umbilical cord arterial pH were used to assess neonates.

Results

We found a strong correlation between the presence of the sucking reflex and umbilical cord arterial pH (r = 0.32; p = 0.018981). Umbilical cord arterial pH was also correlated with the presence of asymmetric tonic neck reflex (r = 0.27; p = 0.047124), cost of attention (r = 0.31; p = 0.025381) and general motor maturity (r = 0.34; p = 0.011741).

Conclusions

We found that the sucking reflex may be affected in infants with low umbilical cord arterial pH values. Practitioners and parents can use the NBAS to help determine neurodevelopmental factors and outcomes in preterm infants, possibly leading to safer and more effective feeding practices and interventions.

A silver nanowire-based flexible pressure sensor to measure the non-nutritive sucking power of neonates

Preterm infants are prone to have higher risks of morbidity, disability and developmental delay compared to term infants. The primitive reflexes, inborn behaviors found in early life development, are shown to be a good tool to assess the integrity of the central nervous system of infants and to predict potential malfunctions. Among these reflexes, the non-nutritive sucking reflex plays an important role in indicating congenital abnormalities in brain development and feeding readiness, especially for premature infants. Conventionally, pediatricians evaluate the oral sucking power qualitatively based on their experiences, by using a gloved finger put inside the infant’s mouth. Thus, more quantitative solutions to assess the sucking power of preterm infants are necessary to support healthcare professionals in their evaluation procedures. Here, we developed a silver nanowire (AgNW)-based flexible pressure sensor to measure the non-nutritive sucking power of infants. The flexible sensor was fabricated using silver nanowires deposited on polydimethylsiloxane (PDMS) in a sandwich-like structure. The sensor based on the principle of strain gauge was attached to a ring-shaped connecting module, and then to a pacifier. The negative sucking pressure exerted by the infant deformed the sensor membrane, causing its electrical resistance to change without any contact between the infant’s mouth and the sensing element. The fabricated sensor was characterized and optimized to achieve both the suitable sensitivity and stability. Thanks to the excellent long-term electro-mechanical stability and high sensitivity, the developed sensor is expected to provide the means to quantitatively assess the non-nutritive sucking of infants, with a portable, low-cost, non-invasive and light-weight solution.

Quantitative assessment of nutritive sucking patterns in preterm infants

OBJECTIVE

To assess patterns of nutritive sucking in very preterm infants ≤32 weeks of gestation.

STUDY DESIGN

Very preterm infants who attained independent oral feeding were prospectively assessed with an instrumented feeding bottle that measures nutritive sucking. The primary outcome measure was nutritive sucking performance at independent oral feeding.

RESULT

We assessed nutritive sucking patterns in 33 very preterm infants. We recorded 63 feeding sessions. The median number of sucks was 784 (IQR: 550-1053), the median sucking rate was 36/min (IQR: 27-55), and the median number of sucking bursts during the first 5 min of oral feeding was 14 (IQR: 12-16). Maximum sucking strength correlated with the number of sucks (r = 0.62; p < 0.01). No safety concerns were identified during the study.

CONCLUSION

The quantitative analysis of nutritive sucking patterns with a newly developed instrumented bottle in stable, very preterm infants is safe and feasible. More research is needed to develop and refine the instrument further.

Association of uncoordinated sucking pattern with developmental outcome in premature infants: a retrospective analysis

Background

Stress signals during sucking activity such as nasal flaring, head turning, and extraneous movements of the body have been attributed to incoordination of sucking, swallowing, and respiration (SSR) in premature infants. However, the association of uncoordinated sucking pattern with developmental outcomes has not yet been investigated. The aim of this study was to investigate whether uncoordinated sucking pattern during bottle-feeding in premature infants is associated with the developmental outcomes at 8–12 and 18–24 months of age (corrected for prematurity).

Methods

We retrospectively reviewed the medical records and video recordings for the Neonatal Oral-Motor Assessment Scale (NOMAS) of premature infants and divided them into two groups based on the presence or absence of incoordination. The Bayley-III cognition composite scores of the incoordination-positive and incoordination-negative group were compared at 8–12 and 18–24 months of age.

Results

Seventy premature infants exhibited a disorganized sucking pattern according to the NOMAS. The average Bayley-III cognition composite scores at 8–12 months of age were 92.5 ± 15.6 and 103.0 ± 11.3 for the incoordination-positive (n = 22) and incoordination-negative groups (n = 48), respectively (p = 0.002). The average Bayley-III cognition composite scores at 18–24 months were 90.0 ± 17.9 and 100.7 ± 11.5 for the incoordination-positive (n = 21) and incoordination-negative groups (n = 46), respectively (p = 0.005). A multiple linear regression analysis indicated that the presence of uncoordinated sucking pattern, grade 3 or 4 germinal matrix hemorrhage–intraventricular hemorrhage, and moderate to severe bronchopulmonary dysplasia were independently associated with cognitive development at 18–24 months of age.

Conclusions

Uncoordinated sucking pattern in premature infants was independently associated with a higher risk of abnormal developmental outcome in the cognitive domain of the Bayley-III at both 8–12 and 18–24 months. There may be a need for periodic follow-up and early intervention for developmental delay when incoordination of SSR that results in stress signals on the NOMAS is observed before 40 weeks postmenstrual age.

Nutritive sucking abnormalities and brain microstructural abnormalities in infants with established brain injury: a pilot study

OBJECTIVE

To determine the relationship between nutritive sucking and microstructural integrity of sensorimotor tracts in newborns with brain injury.

STUDY DESIGN

Diffusion imaging was performed in ten newborns with brain injury. Nutritive sucking was assessed using Nfant®. The motor, sensory, and corpus callosum tracts were reconstructed via tractography. Fractional anisotropy, radial, axial, and mean diffusivity were estimated for these tracts. Multiple regression models were developed to test the association between sucking features and diffusion parameters.

RESULTS

Low-sucking smoothness correlated with low-fractional anisotropy of motor tracts (p = 0.0096). High-sucking irregularity correlated with high-mean diffusivity of motor (p = 0.030) and corpus callosum tracts (p = 0.032). For sensory tracts, high-sucking irregularity (p = 0.018) and low-smoothness variability (p = 0.002) correlated with high-mean diffusivity.

INTERPRETATION

We show a correlation between neuroimaging-demonstrated microstructural brain abnormalities and variations in sucking patterns of newborns. The consistency of this relationship should be shown on larger cohorts.

A comparison of the nutritive sucking performance of full term and preterm neonates at hospital discharge: A prospective study

BACKGROUND

Studies show that 40% to 70% of premature infants exhibit both immature and atypical feeding ability. To establish thresholds of performance and develop efficacious treatments for initiating and advancing oral feedings, we must first identify the nutritive sucking performance measures impacted by preterm birth.

AIMS

To compare objective measures of neonatal nutritive sucking between full term and preterm infants at hospital discharge.

STUDY DESIGN AND METHODS

This was a prospective observational study including full term (FT; N = 32) and preterm (PT; N = 44) infants. Nutritive sucking performance at discharge was assessed. The outcome measures of interest were means and coefficients of variability of nutritive sucking peak amplitude, frequency, duration, and smoothness, and feeding-related length of stay.

RESULTS

There was a significant difference in sucking performance between groups; FT infants demonstrated significantly lower mean suck frequency, with longer suck duration and greater suck smoothness as compared to PT. PT infants had significantly less variability in suck amplitude and frequency as compared to FT, while FT infants had significantly less variability in suck smoothness as compared to PT. Post hoc regression analyses found suck frequency alone accounted for 28% of the variance in feeding length of stay for PT; suck smoothness alone accounted for 34% of the variance in feeding length of stay for FT.

CONCLUSIONS

Suck frequency may be an important intervention target for PT infants having difficulty transitioning to oral feeding. Suck smoothness may be a sensitive marker for identifying infants at high risk for feeding challenges.

Quantifying the Impact of Common Feeding Interventions on Nutritive Sucking Performance Using a Commercially Available Smart Bottle

An estimated 25% to 40% of infants experience difficulties with learning to breast- or bottle-feed. Yet, guidelines and evidence-based support for common feeding practices are limited. The objective of this case report was to quantify the impact of feeding interventions on nutritive sucking performance after discharge in an outpatient setting. This observational case series involved 2 infants. To determine the impact of cumulative interventions, pre- and postintervention effect sizes were calculated. Sucking performance metrics of interest included nipple movement peak sucking amplitude, duration, frequency, and smoothness. Interventions included positional changes and changes in nipple flow rate, among others. For both infants, cumulative interventions had the greatest impact on suck frequency; postintervention, infants were able to increase their rate of nutritive sucking per burst. Other aspects of sucking performance were differentially impacted for each baby. Researchers agree that neonatal and infant feeding has been understudied and that the evidence for common interventions needs to be strengthened. We have demonstrated the implementation of readily available technology that can be used to quantify the direct impact of any intervention on actual sucking performance. In doing so, we can individualize care to support skill development and improve outcomes for infants at risk for ongoing feeding challenges.

Quantification of nutritive sucking among preterm and full-term infants

Purpose

We developed summaries of oral bottle-feeding skills among preterm (<37 gestational weeks) and full-term (≥37 gestational weeks) infants using a mechanical device (Orometer) to measure intraoral pressure changes, with accompanying automated software and analytics. We then compared the rates of change in feeding skills over several weeks (feeding trends) between preterm and full-term infants. We also compared group means at 40 weeks post menstrual age (PMA).

Patients and methods

Healthy full-term and preterm infants capable of oral feeding were recruited from the Pediatric Outpatient Clinic at University of California San Francisco, Fresno, and from the Oregon Health & Science University Doernbecher Neonatal Critical Care Unit, respectively. Feeding skill was quantified using an Orometer and automated suck-analysis software. Factor analysis reduced the >40 metrics produced by the Orometer system to the following seven factors that accounted for >99% of the sample covariance: suck vigor, endurance, resting, irregularity, frequency, variability, and bursting. We proposed that these factors represent feeding skills and they served as the dependent variables in linear models estimating trends in feeding skills over time for full-term and preterm infants (maturation). At approximately 40 weeks PMA we compared mean feedings skills between infants born preterm and those born full-term using predictions from our models.

Results

Feeding skills for 117 full-term infants and 82 preterm infants were first captured at mean PMA of 42.3 and 36.0 weeks, respectively. For some feeding skills, preterm and full-term infants showed different trends over time. At 37-40 weeks PMA, preterm infants took approximately 15% fewer sucks than infants born full-term (p=0.06) and generally had weaker suck vigor, greater resting, and less endurance than full-term babies. Preterm infant-feeding skills appeared similar to those of full-term infants upon reaching ≥40 weeks PMA, although preterm infants showed greater variability for all factors.

Conclusion

The Orometer device, accompanying software, and analytic methods provided a framework for describing trends in oral feeding, thereby allowing us to characterize differences in maturation of feeding between healthy preterm and full-term infants.