Feeding patterns of full-term and preterm infants at forty weeks postconceptional age

PremieFeed: Investigating Preterm Infant Feeding Behaviors, Growth, and Caregiver Experiences in the First Weeks After NICU Discharge

PURPOSE

This study aimed to longitudinally investigate the preterm infant feeding regimens, feeding behaviors, effect on infant growth, and caregiver perceptions and experiences with feeding in the first 4 weeks following hospital discharge.

BACKGROUND

Preterm infants face high nutritional risk due to their underdeveloped gastrointestinal systems and feeding coordination.

METHODS

Caregivers of preterm infants were recruited to participate in a weekly telephone survey for the first 4 weeks following the infant's hospital discharge. Responses for infant feeding behaviors and caregiver experiences were scored on a 3-point Likert scale. Growth and feeding data were collected from the infant's first neonatal intensive care unit (NICU) developmental follow-up visit.

RESULTS

Twenty-four caregivers completed the study. Changes in feeding regimens were common (8/24 infants; 33%), with the percentage of infants receiving any human milk feedings decreasing from 70% at hospital discharge to 54% at 4 weeks post-discharge. Poor infant feeding skills were weakly associated with poor caregiver feeding experiences, and 46% of caregivers reported contacting their healthcare provider with feeding-related questions. Thirty-eight percent of infants required nutritional intervention at NICU developmental follow-up visit. Infants who received fortified feedings during the first 4 weeks after hospital discharge grew an average of 2.5 g/day faster than infants who did not receive fortified feedings.

CONCLUSION

The postdischarge period for preterm infants is characterized by feeding regimen changes, a decrease in human milk use, and caregiver questions about feeding.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Future studies should further investigate the period after hospital discharge to enable better feeding support for preterm infants and their caregivers.

A Review of Quantitative Instruments for Understanding Breastfeeding Dynamics

Breastfeeding, as a unique behavior of the postpartum period and an ideal source of nourishment, is profoundly impacted by the physiology and behavior of both mothers and infants. For more than three-quarters of a century, there has been an ongoing advancement of instruments that permit insight into the complex process of latching during breastfeeding, which includes coordinating sucking, swallowing, and breathing. Despite the available methodologies for understanding latching dynamics, there continues to be a large void in the understanding of infant latching and feeding. The causes for many breastfeeding difficulties remain unclear, and until a clearer understanding of the mechanics involved is achieved, the struggle will continue in the attempts to aid infants and mothers who struggle to breastfeed. In this review, the history of development for the most prominent tools employed to analyze breastfeeding dynamics is presented. Additionally, the importance of the most advanced instruments and systems used to understand latching dynamics is highlighted and how medical practitioners utilize them is reported. Finally, a controversial argument amongst pediatric otolaryngolo gists concerning breastfeeding difficulties is reviewed and the urgent need for quantification of latching dynamics in conjunction with milk removal rate through prospective controlled studies is discussed.

Correlates and Trajectories of Preterm Infant Sucking Patterns and Sucking Organization at Term Age

BACKGROUND

Premature infants may experience increased difficulty with nutrition and growth. Successful oral feeding is an important factor associated with discharge readiness. Despite the importance of feeding as a growth-fostering process, little empiric evidence exists to guide recommendations for early interventions.

PURPOSE

Evaluate whether specific elements of sucking, during preterm initiation of oral feeding, predict sucking organization at corrected term age.

METHODS

Sucking performance of 88 preterm infants born between 24 and 34 weeks of post-menstrual age was measured at baseline and term (33-35 and 40 ± 1.5 weeks). Participants were divided into 4 groups (quartiles) based on initial measures of performance including number of sucks, number of bursts, sucks per burst, and maximum pressure. Stability in sucking organization was assessed by comparing changes in infant's quartile location from baseline to term.

RESULTS

A correlation between quartile location was observed for mean maximum pressure (PMAX): infants with PMAX in the lowest quartile (poorest performance) were significantly more likely to remain in the lowest quartile at term (P < .000); infants in the highest quartile (best performance) at baseline were significantly more likely to be in the highest quartile at term (P < .000).

IMPLICATION FOR PRACTICE

Infants with the weakest sucking pressures at 34 weeks of post-menstrual age continue to be at risk for less than optimal feeding skills at 40 weeks of post-menstrual age. Early identification of at-risk infants may allow for effective interventions to potentially decrease long-term feeding problems.

IMPLICATIONS FOR RESEARCH

Future research should focus on the development of personalized interventions to address attributes of problematic feeding such as sucking efficiency.

The Effect of Severe Intraventricular Hemorrhage on the Biorhythms of Feeding in Premature Infants

Background: Suck-swallow rhythmicity and the integration of breathing into infant feeding are developmentally regulated. Neurological injury and breathing abnormalities can both impact feeding in preterm infants. Objective: To determine the effects of neurologic injury independent of effects of disordered breathing on feeding biorhythms in premature infants. Methods: Low-risk preterm infants (LRP), infants with Grade 3-4 Intraventricular Hemorrhage (IVH), those with bronchopulmonary dysplasia (BPD), and those with both BPD and IVH (BPD+IVH) were identified. Forty-seven infants, 32-42 weeks Postmenstrual Age (PMA) were evaluated on one or more occasions (131 studies). Of these, 39 infants (81 studies) were performed at >35 weeks PMA. Coefficient of variation (COV) (=standard deviation of the inter-event (e.g., suck-suck, swallow-breath, etc.) interval divided by the mean of the interval) was used to quantify rhythmic stability. Results: To adjust for PMA, only those infants >35-42 weeks were compared. Suck-suck COV was significantly lower (more rhythmically stable) in the LRP group [COV = 0.274 ± 0.051 (S.D.)] compared to all other groups (BPD = 0.325 ± 0.066; IVH = 0.342 ± 0.072; BPD + IVH = 0.314 ± 0.069; all p < 0.05). Similarly, suck-swallow COV was significantly lower in LRP babies (0.360 ± 0.066) compared to the BPD group (0.475 ± 0.113) and the IVH cohort (0.428 ± 0.075) (p < 0.05). The BPD+IVH group (0.424 ± 0.109), while higher, was not quite statistically significant. Conclusions: Severe IVH negatively impacts suck-suck and suck-swallow rhythms. The independent effect of neurological injury in the form of IVH on feeding rhythms suggests that quantitative analysis of feeding may reflect and predict neurological sequelae.

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.

Preterm infant feeding performance at term equivalent age differs from that of full-term infants

OBJECTIVE

To identify differences in feeding skill performance among preterm infants at term equivalent age compared with full-term infants.

STUDY DESIGN

Ninety-two infants (44 preterm infants born ≤32 weeks gestation at term equivalent age and 48 full-term infants within 4 days of birth) had a standardized oral feeding assessment.

RESULT

Preterm infants at term equivalent age had lower Neonatal Eating Outcome Assessment scores (67.8 ± 13.6 compared with 82.2 ± 8.1; p < 0.001) and were more likely to have poor arousal (p = 0.04), poor tongue positioning (p = 0.04), suck-swallow-breathe discoordination (p < 0.001), inadequate sucking bursts (p = 0.01), tonal abnormalities (p < 0.001), discoordination of the jaw and tongue during sucking (p < 0.001), lack of positive engagement with the feeder and/or discomfort (p < 0.001), signs of aspiration (p < 0.001), difficulty regulating breathing (p < 0.001), and have an inability to maintain an appropriate state (p < 0.001), and complete the feeding (<0.001).

CONCLUSION

A broad range of feeding-related difficulties appear to remain evident in preterm infants at term equivalent age.

Nutrition in late preterm infants

Late preterm infants comprise the majority of preterm infants, yet there are few data to support best nutritional practice for these infants. Breastmilk is considered the best choice of enteral feeding for late preterm infants. However, supplementation of breastmilk may be indicated to promote optimal growth. Preterm formulas can be used for supplementation of breastmilk or as a breastmilk substitute but there is little evidence for their use in the late preterm infant. Feeding difficulties are common and some infants require intravenous nutritional support soon after birth. Others require tube feeding until full sucking feeds are established. Future research should focus on whether nutritional support of late preterm babies pending exclusive breastfeeding influences growth, body composition and long-term outcomes of late preterm infants and, if so, how nutritional interventions can optimise these outcomes.

Pharyngeal contractile and regulatory characteristics are distinct during nutritive oral stimulus in preterm-born infants: Implications for clinical and research applications

BACKGROUND

Maturation of pharyngeal swallowing during neonatal oral feeding is unknown. Our objective was to evaluate pharyngeal functioning using high-resolution manometry (HRM) during nutritive oral stimulus and test the hypothesis that pharyngeal contractility and regulation are distinct in preterm-born infants.

METHODS

High-resolution manometry data during oral milk feeding were analyzed for pharyngeal contractile (PhCI, mm Hg cm s) and regulatory (number and frequency of pharyngeal contractions and bursts, pharyngeal activity-to-quiescence ratio, upper esophageal sphincter nadir pressure) characteristics in 23 preterm (<38 weeks' gestation) and 18 full-term-born infants at term maturation. Mixed linear models and stepwise regression methods were used.

RESULTS

Despite more oral feeding experiences (P < 0.05), preterm infants (vs full-term), consumed less milk volume (P < 0.001), had lesser pharyngeal contractions within bursts (P = 0.04), lower pharyngeal contraction frequency (P < 0.01), and lower pharyngeal activity (P = 0.03), but higher PhCI per individual contraction (P = 0.01). PhCI is higher for longer PMA (P < 0.05), higher UES nadir pressures (P < 0.05), and lower pharyngeal contraction frequency (P < 0.05).

CONCLUSIONS

Nutritive oral milk stimulus provoked pharyngeal contractility characteristics is distinct in preterm-born. Despite more oral nutritive experiences, preterm infants had underdeveloped excitatory and inhibitory rhythmic activity. Cranial nerve IX and X effects on sensory-motor responses and feedback (excitation-inhibitory rhythm regulation) remain immature among preterm-born even at full-term maturational status. We speculate the relationship between PhCI and UES regulatory activity contributes to the observed differences in preterm and full-term infants.

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.

Non-Nutritive Sucking in the Preterm Infant

OBJECTIVE

To identify the progression of non-nutritive sucking (NNS) across postmenstrual age (PMA) and to investigate the relationship of NNS with medical and social factors and oral feeding.

STUDY DESIGN

Fifty preterm infants born at ≤32 weeks gestation had NNS assessed weekly starting at 32 weeks PMA with the NTrainer System. Oral feeding was assessed at 38 weeks PMA.

RESULTS

There were increases in NNS bursts per minute (p = 0.005), NNS per minute (p < 0.0001), NNS per burst (p < 0.001), and peak pressure (p = 0.0003) with advancing PMA. Level of immaturity and medical complications were related to NNS measures (p < 0.05). NNS measures were not related to Neonatal Oral Motor Assessment Scale scores. Smaller weekly change in NNS peak pressure (p = 0.03; β = -1.4) was related to feeding success at 38 weeks PMA.

CONCLUSION

Infants demonstrated NNS early in gestation. Variability in NNS scores could reflect medical complications and immaturity. More stable sucking pressure across time was related to feeding success at 38 weeks PMA.

A Novel System to Measure Infants' Nutritive Sucking During Breastfeeding: the Breastfeeding Diagnostic Device (BDD)

Breastfeeding is optimal for infant health, but more than 66% of mothers cease exclusive breastfeeding within three months after giving birth. Evaluating infants’ sucking effort provides valuable diagnosis to mothers encountering barriers with breastfeeding. Sucking microstructure is defined as an array of metrics that comprehensively capture infants’ ability to create a sealed latch onto mother’s nipple and regulate feeding, including number of sucks, sucks per burst, number of bursts, intra suck interval, and maximal sucking pressure. In this paper, we proposed a breastfeeding diagnostic device (BDD) which allows convenient and objective measurement of infants’ sucking microstructure in both home and clinical settings. BDD utilizes an air-based pressure transducer to measure infants’ sucking behavior. We conducted pilot clinical studies on six dyads of mother and infant to test the feasibility of the BDD system. To facilitate comparison, both breastfeeding and bottle-feeding were conducted on the six dyads using the BDD in home settings, and the outcomes are comparable with prior recordings in research or clinical settings. By offering a convenient and objective measurement of the sucking microstructure, the BDD will provide clinically meaningful guidance and diagnosis to mothers struggling with breastfeeding. BDD will also serve as an objective metric useful in research areas relevant to infant behaviors, assessment of neurodevelopment, and potentially a screening tool for developmental disabilities.

Is nutritional support needed in late preterm infants?

Background

Late preterm birth accounts for 70 % of all preterm births. While the impact of feeding problems in very preterm infants has been widely investigated, data on late preterm infants’ feeding issues are scarce. The aim of the present study was to investigate the need of nutritional support during hospital stay in a cohort of late preterm infants and to identify the factors that most contribute to its occurrence.

Methods

We analyzed the medical records of late preterm infants, born 2011–2013, admitted to a single institution. Neonatal data, the need for nutritional support, defined as the need for parenteral nutrition or intravenous fluids or tube feeding, and the feeding status at discharge were retrieved. The occurrence of respiratory distress syndrome, congenital malformations/chromosomal diseases, cardiac diseases, sepsis, hypoglycemia, poor feeding and the need for surgical intervention were also collected.

Results

A total of 1768 late preterm infants were included. Among the 592 infants requiring a nutritional support, 228 developed a respiratory distress syndrome, two developed a sepsis, one presented with a cardiac disease, 24 underwent a surgical intervention, eight had a chromosomal disease/congenital malformation, 80 had hypoglycemia. In addition, 100 infants required nutritional support due to poor feeding and 149 were born small for gestational age. Birth weight ≤2000 g (adjusted OR = 12.2, 95 % CI 7.5-19.9, p < 0.0001), gestational age of 34 weeks (adjusted OR = 4.08, 95 % CI 2.8-5.9, p < 0.0001), being small for gestational age (adjusted OR = 2.17, 95 % CI 2.8-5.9, p=0.001), having a respiratory distress syndrome (adjusted OR = 79.6, 95 % CI 47.2-134.3, p < 0.0001) and the need of surgical intervention (adjusted OR = 49.4, 95 % CI 13.9-174.5, p < 0.0001) were associated with a higher risk of need of nutritional support during hospital stay.

Conclusions

Late preterm infants are at relatively high risk of requiring nutritional support during hospital stay, especially if they have a birth weight ≤2000 g, a gestational age of 34 weeks, are born small for gestational age, develop a respiratory distress syndrome and require a surgical intervention. The present findings add to the knowledge of late preterm infants’ feeding issues and may contribute to tailoring nutritional approaches for these infants.

Milk Flow Rates From Bottle Nipples Used for Feeding Infants Who Are Hospitalized

PURPOSE

This study tested the milk flow rates and variability in flow of currently available nipples used for bottle-feeding infants who are hospitalized.

METHOD

Clinicians in 3 countries were surveyed regarding nipples available to them for feeding infants who are hospitalized. Twenty-nine nipple types were identified, and 10 nipples of each type were tested by measuring the amount of infant formula expressed in 1 min using a breast pump. Mean milk flow rate (mL/min) and coefficient of variation were used to compare nipples within brand and within category (i.e., Slow, Standard, Premature).

RESULTS

Flow rates varied widely between nipples, ranging from 2.10 mL/min for the Enfamil Cross-Cut to 85.34 mL/min for the Dr. Brown's Y-Cut Standard Neck. Variability of flow rates among nipples of the same type ranged from a coefficient of variation of 0.05 for Dr. Brown's Level 1 Standard- and Wide-Neck to 0.42 for the Enfamil Cross-Cut. Mean coefficient of variation by brand ranged from 0.08 for Dr. Brown's to 0.36 for Bionix.

CONCLUSIONS

Milk flow is an easily manipulated variable that may contribute to the degree of physiologic instability experienced by infants who are medically fragile during oral feeding. This study provides clinicians with information to guide appropriate selection of bottle nipples for feeding infants who are hospitalized.

Multisensory intervention for preterm infants improves sucking organization

BACKGROUND

Premature infants are at risk for difficulties in feeding, social interaction, and growth. Many premature infants exhibit a lower capacity for self-regulation, resulting in less behavioral alertness and hypersensitivity to stimulation. Feeding is critically important because it is a primary factor for infant growth and a major concern for both parents and clinicians.

PURPOSE

The aim of this randomized controlled trial was to evaluate sucking organization in premature infants following a preterm infant multisensory intervention, the Auditory, Tactile, Visual, and Vestibular (ATVV) intervention.

METHODS

A convenience sample of 183 healthy premature infants born 29-34 weeks postmenstrual age (PMA) enrolled. Sucking organization was measured at baseline, then weekly, during the infant's hospital stay.

RESULTS

A quadratic trend was observed for number of sucks, sucks per burst, and maturity index with the intervention group increasing significantly faster by day 7 (model estimates for group × day: β= 13.69, P < .01; β = 1.16, P < .01; and β= 0.12, P < .05, respectively). Sucking pressure increased linearly over time, with significant between-group differences at day 14 (β= 45.66, P < .01).

IMPLICATIONS FOR PRACTICE

The ATVV infants exhibited improved sucking organization during hospitalization, suggesting that the ATVV intervention improves maturation of oral feeding.

IMPLICATIONS FOR RESEARCH

Further research that includes 2 or more tests, delivered the same day and/or over consecutive days, will provide researchers and clinicians a more sensitive indicator of maturational changes in feeding behaviors.

The association between sucking behavior in preterm infants and neurodevelopmental outcomes at 2 years of age

OBJECTIVE

To evaluate whether a specific period after birth (in weeks postmenstrual age [PMA]) and specific elements of sucking are associated with abnormal neurodevelopmental outcomes at age 2 years using a longitudinal approach.

STUDY DESIGN

Fifty-two preterm infants participated in this longitudinal cohort study (mean gestational age, 29.5 weeks; mean birth weight, 1197 g). We assessed the infants' sucking patterns at 37-50 weeks PMA using the Neonatal Oral-Motor Assessment Scale. At age 2 years, based on a neurologic examination and the Dutch version of the Bayley Scales of Infant and Toddler Development, Second Edition, we categorized the children as developing normally (n = 39) or abnormally (n = 13). ORs, including 95% CIs, were calculated to ascertain the risk of abnormal neurodevelopmental outcomes.

RESULTS

The inability to sustain sucking at 46 weeks PMA (OR, 6.25; 95% CI, 1.29-30.35) and the absence of a mature sucking pattern at 44 weeks PMA (OR, 6.30; 95% CI, 1.40-28.32) significantly increased the odds of abnormal neurodevelopmental outcomes at age 2 years. The ORs of the Neonatal Oral-Motor Assessment Scale items assessing rhythmic jaw movements, rhythmic tongue movements, and coordination among sucking, swallowing, and respiration were high shortly after term, but failed to reach significance.

CONCLUSION

Specific elements of sucking at 4-6 weeks postterm are associated with abnormal neurodevelopmental outcomes in preterm infants at age 2 years. This period might be a sensitive time of infant development in which sucking behavior is an early marker of abnormal developmental outcomes. This finding may offer opportunities for early intervention.

Comparison of tongue muscle characteristics of preterm and full term infants during nutritive and nonnutritive sucking

BACKGROUND

Independent oral feeding requires coordination of suck, swallow and breathe and the lingual musculature plays a significant role in this coordinative action. However, clinical benchmarks of lingual function fundamental to successful feeding have not been explored.

AIMS

The present study tests our model for quantifying infant lingual force and size and compares the muscle measures of interest in two cohorts: healthy full-term infants (FT) (N=5) and healthy preterm infants (PT) (N=6).

METHOD

Using an instrumented pacifier and bottle nipple, we determined the resultant compressive forces applied to the nipple by the tongue during nutritive (NS) and nonnutritive sucking (NNS). Muscle size was estimated from measures of posterior tongue thickness using ultrasonography.

RESULTS

After controlling for weight and post menstrual age, statistically significant differences were found between FT and PT infants beginning to feed for NNS frequency and NS tongue force. Clinically significant differences were detected for NNS tongue force and posterior tongue thickness. Additionally, PT infants demonstrated a significant difference in mean tongue force between NS and NNS and FT infants did not. FT infants demonstrated a significant difference in mean frequency between NS and NNS and PT infants did not. Linear regression indicated that mean posterior tongue thickness alone predicted 55% of the variance in NS force.

CONCLUSIONS

Results demonstrate the feasibility of our approach and suggest that infant tongue muscle characteristics necessary for successful feeding differ between healthy full term infants and preterm infants who are beginning oral feeding.

Efficacy of semielevated side-lying positioning during bottle-feeding of very preterm infants: a pilot study

Very preterm (VP, ≤30 wk gestational age) infants are at risk for impaired lung function, which significantly limits their ability to eat. A semielevated side-lying (ESL) position is a feeding strategy that may improve oral feeding by supporting breathing during feeding. The study evaluated the efficacy of the ESL position compared with the semielevated supine (ESU) position on physiological stability and feeding performance of bottle-fed VP infants. Using a within-subject crossover design, 6 VP infants were bottle-fed twice on 1 day, in both the ESL and ESU positions in a random order. Physiological stability (heart rate, oxygen saturation [SaO2], and respiratory characteristics) and feeding performance (percent intake, proficiency, efficiency, and duration of feeding) were measured before and/or during feeding. Very preterm infants fed in the ESL position demonstrated significantly less variation in heart rate, less severe and fewer decreases in heart rate, respiratory rate that was closer to the prefeeding state, shorter and more regular intervals between breaths, and briefer feeding-related apneic events. No significant differences for SaO2 or feeding performance were found. The findings indicate that the ESL position may support better regulation of breathing during feeding, thereby allowing VP infants to better maintain physiological stability throughout feeding.

Evaluating sucking maturation using two pressure thresholds

BACKGROUND

The Medoff-Cooper Nutritive Sucking Apparatus (M-CNSA) has been used to objectively measure sucking maturation in preterm infants. The M-CNSA is able to accurately detect sucking pressures less than 20mmHg, however lower pressure thresholds have not previously been used in research.

AIMS

To determine if differences are observed in the number of sucks and maturation in the number of sucks over time when the minimum pressure threshold used to detect a suck is 7mmHg compared to 20mmHg using the M-CNSA.

STUDY DESIGN

Descriptive.

SUBJECTS

A convenience sample of 171 healthy premature infants born between 29 and 34weeks gestational period who were part of a larger randomized controlled study.

OUTCOME MEASURES

The number of sucks detected during weekly five-minute oral feeding observations using 7mmHg and 20mmHg.

RESULTS

Significantly more sucks were detected using the 7mmHg vs 20mmHg threshold at all time points. At both pressure thresholds, the mean number of sucks detected during the five minute feeding observation increased over time. The difference in the number of sucks detected at 7 and 20mmHg did not change over time (p=0.50).

CONCLUSIONS

Using the lower threshold of 7mmHg compared to 20mmHg resulted in more sucks detected while consistently measuring improvement in sucking over time. Detection of more sucks and sucks at a lower pressure threshold allows clinicians and researchers to more accurately assess oral feeding skills among premature infants.

Developing a Co-Regulated, Cue-Based Feeding Practice: The Critical Role of Assessment and Reflection

Assessment of early feeding skills of vulnerable infants is common practice in neonatal care centers. However, assessment is often merely an identification of feeding outcomes, rather than a description of the infant's capacities and methods of adapting to the feeding challenge. Descriptive assessment of the feeding process takes into account the dynamic nature of feeding and notes changes that occur as the infant matures and gains feeding experience. Assessment of the variability that occurs during the feeding as the challenge changes, due to fatigue or physiologic instability, are critical to understanding the infant's feeding skills. As individual components of the feeding are assessed, such as sucking, swallowing and breathing, a reflective process builds understanding of the patterns of coordination of system components in relation to one another. Taking the whole into account and considering the dynamics of the process is necessary if we are going to select appropriate interventions targeted to the individual infant's feeding skills. Using a very preterm infant case, this paper will illustrate assessment of early feeding skills and demonstrate how reflection on and integration of the components of the assessment identifies potential targets for co-regulated, cue-based feeding.

Videofluoroscopic swallowing study findings in full-term and preterm infants with Dysphagia

OBJECTIVE

To determine the clinical characteristics and videofluoroscopic swallowing study (VFSS) findings in infants with suspected dysphagia and compare the clinical characteristics and VFSS findings between full-term and preterm infants.

METHODS

A total of 107 infants (67 full-term and 40 preterm) with suspected dysphagia who were referred for VFSS at a tertiary university hospital were enrolled in this retrospective study. Clinical characteristics and VFSS findings were reviewed by a physiatrist and an experienced speech-language pathologist. The association between the reasons of referral for VFSS and VFSS findings were analyzed.

RESULTS

Mean gestational age was 35.1±5.3 weeks, and mean birth weight was 2,381±1,026 g. The most common reason for VFSS referral was 'poor sucking' in full-term infants and 'desaturation' in preterm infants. The most common associated medical condition was 'congenital heart disease' in full-term infants and 'bronchopulmonary dysplasia' in preterm infants. Aspiration was observed in 42 infants (39.3%) and coughing was the only clinical predictor of aspiration in VFSS. However, 34 of 42 infants (81.0%) who showed aspiration exhibited silent aspiration during VFSS. There were no significant differences in the VFSS findings between the full-term and preterm infants except for 'decreased sustained sucking.'

CONCLUSION

There are some differences in the clinical manifestations and VFSS findings between full-term and preterm infants with suspected dysphagia. The present findings provide a better understanding of these differences and can help clarify the different pathophysiologic mechanisms of dysphagia in infants.

Oral-motor function and feeding intervention

This article presents the elements of the Oral Motor Intervention section of the Infant Care Path for Physical Therapy in the Neonatal Intensive Care Unit (NICU). The types of physical therapy interventions presented in this path are evidence based as well as infant driven and family focused. In the context of anticipated maturation of suck-swallow-breathe coordination, the timing and methods for initiation of oral feedings and transition from gavage to full breast or bottle-feedings are presented with supporting evidence.

Transition from gavage to nipple feeding for preterm infants with bronchopulmonary dysplasia

BACKGROUND

The transition from gavage to nipple feeding is difficult for preterm infants with bronchopulmonary dysplasia because of tachypnea and hypoxemia from chronic respiratory distress.

OBJECTIVE

The aim of this study was to test the hypothesis that preterm infants with bronchopulmonary dysplasia who transitioned from gavage to nipple feeding with the semidemand method would achieve nipple feeding sooner and be discharged from hospital sooner than control infants who received standard care.

METHODS

Forty-two infants were randomized to the control condition and 44 to the experimental protocol. Mean gestational ages and birth weights were 25 ± 1.5 weeks and 784 g for controls and 25 ± 1.4 weeks and 787 g for experimental infants. Control infants received standard care that included gradual increases in the number of nipple to gavage feedings per day. Experimental infants received the semidemand method that used infant behavioral and cardiorespiratory signs to regulate frequency, length, and volume of nipple feedings. General linear model procedures were used to compare study groups.

RESULTS

Experimental infants achieved nipple feeding at M = 5.9 ± 0.7 days compared with control infants, M = 12.3 ± 0.8 (p < .0001). Length of hospitalization was not significantly different between groups.

DISCUSSION

The semidemand method significantly shortened the time for infants to attain nipple feeding in a manner taking their respiratory distress into consideration.

Changes in Oral Feeding in Preterm Infants Two Weeks After Hospital Discharge

The purpose of this analysis was to measure changes in preterm infant feeding skill between discharge and two weeks post-discharge. Data were from two samples - 22 preterm infants who participated in a non-experimental study of feeding readiness and 63 preterm infants who participated in a study of four oral feeding approaches. Both studies were approved by the institutional review board; parents gave informed consent. The Early Feeding Skills Assessment (EFSA) was used to measure feeding skills. Data were analyzed descriptively and by ANOVA and regression. Analysis revealed that feeding skills changed selectively from discharge to post-discharge and that discharge skills were predictive of post-discharge skill. Changes that occur in feeding skills during the immediate post-discharge period have received little attention from researchers. The findings suggest that enhanced pre-discharge assessment and parent teaching maybe necessary to reduce reported parental stress associated with feeding the newly discharged infant and to promote a positive feeding experience.

Postdischarge feeding patterns in early- and late-preterm infants

OBJECTIVE

To compare the incidence of postdischarge feeding dysfunction and hospital/subspecialty visits for feeding problems during the first year of life in late (34 to 36 6/7 weeks) and early-preterm (25 to 33 6/7 weeks) infants.

METHODS

In this prospective study, the authors sent questionnaires to parents of early (n = 319) and late (n = 571) preterm infants at 3, 6, and 12 months corrected age. Parents' perceptions of infants' feeding skills, comfort with feeding, and hospital/subspecialty visits for feeding difficulties were obtained. Results were analyzed with χ(2) tests and Spearman's correlations.

RESULTS

Early preterms had more oromotor dysfunction at 3 (29% vs 17%) and 12 months (7% vs 4%) and more avoidant feeding behavior at 3 months (33% vs 29%). In both groups, oromotor dysfunction and avoidant feeding behavior improved over time. Frequency of poor appetite and hospitalization/subspecialty visits were similar.

CONCLUSION

Pediatricians should screen all preterm infants for feeding dysfunction during the first year.

Feeding Difficulties in Preterm Infants

Preterm infants often display difficulty establishing oral feeding in the weeks following birth. This article aims to provide an overview of the literature investigating the development of feeding skills in preterm infants, as well as of interventions aimed at assisting preterm infants to develop their feeding skills. Available research suggests that preterm infants born at a lower gestational age and/or with a greater degree of morbidity are most at risk of early feeding difficulties. Respiratory disease was identified as a particular risk factor. Mechanisms for feeding difficulty identified in the literature include immature or dysfunctional sucking skills and poor suck–swallow–breath coordination. Available evidence provides some support for therapy interventions aimed at improving feeding skills, as well as the use of restricted milk flow to assist with maintaining appropriate ventilation during feeds. Further research is needed to confirm these findings, as well as to answer remaining clinical questions.

Sucking patterns and behavioral state in 1- and 2-day-old full-term infants

OBJECTIVE

To provide a comprehensive analysis of the temporal structure of sucking in full-term neonates.

DESIGN

Descriptive study.

SETTING

Newborn nursery in a city teaching institution.

PATIENTS/PARTICIPANTS

Fifty-six full-term infants with a mean birth weight of 3,128±370 g completed sucking assessments on the first and second day of life.

METHODS

A 5-minute sucking assessment was completed on the first and second day of life. Instruments included an Infant Nutritive Sucking Apparatus and the Anderson Behavioral Assessment Scale.

RESULTS

The number of sucks (p<.001), intersuck width (p=.008) and interburst width (p<.05) were significantly different between the first and second day of life. On the second day of life the infants generated significantly more sucks, a decrease in interburst width and a decrease in intersuck width. There was a significant increase in the presence of an alert behavioral state from the first to second sucking assessment (p<.01). In addition, with a more alert infant state there was an increased time spent bursting (p<.001).

CONCLUSION

Our results show that sucking analysis is sensitive to infant status and suggest that the development of sucking methodology can be considered as a useful clinical tool to assess the normal developmental course of sucking patterns.

Quantification of intraoral pressures during nutritive sucking: methods with normal infants

We report quantitative measurements of ten parameters of nutritive sucking behavior in 91 normal full-term infants obtained using a novel device (an Orometer) and a data collection/analytical system (Suck Editor). The sucking parameters assessed include the number of sucks, mean pressure amplitude of sucks, mean frequency of sucks per second, mean suck interval in seconds, sucking amplitude variability, suck interval variability, number of suck bursts, mean number of sucks per suck burst, mean suck burst duration, and mean interburst gap duration. For analyses, test sessions were divided into 4 × 2-min segments. In single-study tests, 36 of 60 possible comparisons of ten parameters over six pairs of 2-min time intervals showed a p value of 0.05 or less. In 15 paired tests in the same infants at different ages, 33 of 50 possible comparisons of ten parameters over five time intervals showed p values of 0.05 or less. Quantification of nutritive sucking is feasible, showing statistically valid results for ten parameters that change during a feed and with age. These findings suggest that further research, based on our approach, may show clinical value in feeding assessment, diagnosis, and clinical management.

Neonatal neurobehavioral organization after exposure to maternal epidural analgesia in labor

OBJECTIVE

To explore relationships between maternal epidural analgesia and two measures of neurobehavioral organization in infants at the initial feeding 1 hour after birth.

DESIGN

Prospective comparative design.

SETTING

Inner-city community hospital, Chicago, Illinois.

PARTICIPANTS

Convenience sample of 52 low-risk, mainly Black and Latino, mother/infant dyads.

METHODS

Mothers self-selected to labor with epidural or no labor pain medication. Neonatal neurobehavioral organization was measured in term infants at the initial feeding 1 hour after birth. A nutritive sucking apparatus generated data on total number of sucks and sucking pressure. Video recordings of infants (before and after the initial feeding) were coded for behavioral states, with analysis on frequency of alertness.

RESULTS

Total number of sucks and sucking pressure were not related to epidural exposure, although an epidural drug dosage effect on total number of sucks was evident when gender was a factor. Unmedicated girls demonstrated more sucks than girls in the high-dosage epidural group (p=.027). Overall, girls exhibited stronger sucking pressure than boys (p=.042). Frequency of alertness was not related to epidural exposure, although longer labor was related to greater alertness (p=.003), and Latino infants were more alert than Black infants (p=.002).

CONCLUSIONS

Results suggest attenuated neonatal nutritive sucking organization in girls after exposure to high maternal epidural dosages. In comparison to boys, girls may have enhanced neurobehavioral organization at birth. Race/ethnicity and alertness may have spurious associations in which hidden factors drive the relationship.

Mechanics of sucking: comparison between bottle feeding and breastfeeding

Background

There is very little evidence of the similarity of the mechanics of maternal and bottle feeding. We assessed the mechanics of sucking in exclusive breastfeeding, exclusive bottle feeding, and mixed feeding. The hypothesis established was that physiological pattern for suckling movements differ depending on the type of feeding. According to this hypothesis, babies with breastfeeding have suckling movements at the breast that are different from the movements of suckling a teat of babies fed with bottle. Children with mixed feeding mix both types of suckling movements.

Methods

Cross-sectional study of infants aged 21-28 days with only maternal feeding or bottle feeding (234 mother-infant pairs), and a randomized open cross-over field trial in newborns aged 21-28 days and babies aged 3-5 months with mixed feeding (125 mother-infant pairs). Primary outcome measures were sucks and pauses.

Results

Infants aged 21-28 days exclusively bottle-fed showed fewer sucks and the same number of pauses but of longer duration compared to breastfeeding. In mixed feeding, bottle feeding compared to breastfeeding showed the same number of sucks but fewer and shorter pauses, both at 21-28 days and at 3-5 months. The mean number of breastfeedings in a day (in the mixed feed group) was 5.83 ± 1.93 at 21-28 days and 4.42 ± 1.67 at 3-5 months. In the equivalence analysis of the mixed feed group, the 95% confidence interval for bottle feeding/breastfeeding ratio laid outside the range of equivalence, indicating 5.9-8.7% fewer suction movements, and fewer pauses, and shorter duration of them in bottle feeding compared with breastfeeding.

Conclusions

The mechanics of sucking in mixed feeding lay outside the range of equivalence comparing bottle feeding with breastfeeding, although differences were small. Children with mixed feeding would mix both types of sucking movements (breastfeeding and bottle feeding) during the learning stage and adopt their own pattern.

Maturational changes in the feeding behaviour of infants - a comparison between breast-feeding and bottle-feeding

AIM

To obtain a better understanding of the changes in feeding behaviour from 1 to 6 months of age. By comparing breast- and bottle-feeding, we intended to clarify the difference in longitudinal sucking performance.

METHODS

Sucking variables were consecutively measured for 16 breast-fed and eight bottle-fed infants at 1, 3 and 6 months of age.

RESULTS

For breast-feeding, number of sucks per burst (17.8 +/- 8.8, 23.8 +/- 8.3 and 32.4 +/- 15.3 times), sucking burst duration (11.2 +/- 6.1, 14.7 +/- 8.0 and 17.9 +/- 8.8 sec) and number of sucking bursts per feed (33.9 +/- 13.9, 28.0 +/- 18.2 and 18.6 +/- 12.8 times) at 1, 3 and 6 months of age respectively showed significant differences between 1 and 6 months of age (p < 0.05). The sucking pressure and total number of sucks per feed did not differ among different ages. Bottle-feeding resulted in longer sucking bursts and more sucks per burst compared with breast-feeding in each month (p < 0.05).

CONCLUSION

The increase in the amount of ingested milk with maturation resulted from an increase in bolus volume per minute as well as the higher number of sucks continuously for both breast- and bottle-fed infants.

Deprivation and dysphagia in premature infants

The developmental trajectory of feeding features increasingly rhythmic ingestive behavior patterns. Sucking and swallowing by the fetus and infant, including fetal consumption of amniotic fluid, depend upon brainstem central pattern generators whose activity is increasingly influenced by chemosensory and oral-tactile input. This neurobiological fact underlies the clinical discovery that oral-tactile stimulation via pacifier stimulates ingestive behavior in tube-fed, premature infants and improves their feeding skills. However, little is known regarding the degree to which oral sensory deprivation may contribute to feeding problems in these patients. Evidence of deprivation-induced neuropathologic effects in rodents further underlines the potential impact of sensory deprivation in premature newborns, whose transition period from tube to oral feeding often lasts weeks beyond term equivalent gestational age. Studies exploring the link between early dysphagia and later developmental impairment could clarify experiential antecedents of cerebral injury. Trials of sensory interventions to promote feeding development are warranted.

Nutritive sucking pattern--from very low birth weight preterm to term newborn

The contribution of maturation and stimulation to the development of oral feeding was investigated, with two main objectives: (1) to analyze the nutritive sucking pattern of very-low-birth-weight newborns from their first oral feeding to the acquisition of independent oral feeding, and (2) to compare the nutritive sucking patterns of these babies, after feeding autonomy, with healthy term newborns.

METHODS

Two groups were considered for analysis. Group 1: N=15 Very-Low-Birth-Weight (VLBW), gestacional age (GA)=28.15+/-1.5, birth weight (BW)=1178.3+/-174.4. The intervention program began at 30.19+/-1.52 weeks GA. Group 2: N=25 term newborns, healthy, GA=39.04+/-1.2, BW=3370.42+/-310.76. Repeated measures of the following variables were taken (weekly for group 1): suction efficacy (SEF), rhythm of milk transfer (RMT), suctions, bursts and pauses. Group 2 was analysed only once between the 2nd and 5th day of life.

RESULTS

Group 1 has revealed a minimal suction number at 32 GA weeks (82+/-77.6) and maximal suction number at 36-37 GA weeks (162.7+/-60.7). The number of sucks seemed to be dependent of weight (p=0.005), duration of intervention (p=0.001) and chronological age (p=0.000). Significant statistical effects of gestational age were not observed (p=0.904). Sucks in bursts represented 77% at the beginning of oral feeding (32 weeks GA), and 96% at 33 weeks GA, remaining constant thereafter. The number of sucks and bursts increased with GA and weeks of feeding. The mean duration of the pauses decreased from first to fourth week of feeding (week1=14.1+/-9.1 and week4=6.4+/-1.4 s). The sucking efficacy (SEF) was better explained by weight (p=0.000), number of sucks in 5 min (p=0.025) and chronological age (p=0.044). Gestational age (p=0.051) and nutritive intervention duration (NDI) (p=0.110) did not contribute to explain SEF. Despite the observation of significant statistical differences between groups regarding GA (35.9/39.08; p=0.00), chronological age (53.3/2.5; p=0.00) and weight (1875/3360; p=0.00), the nutritive suction pattern was not statistically different between groups after feeding autonomy.

CONCLUSION

in VLBW oral feeding before 32 weeks GA allows the attainment of a mature nutritive suction pattern before term (37-40 weeks). Experience seems to be one of the influencing factors in the change of the nutritive suction pattern.

Sucking behavior of preterm neonates as a predictor of developmental outcomes

OBJECTIVES

The relationship between the pattern of sucking behavior of preterm infants during the early weeks of life and neurodevelopmental outcomes during the first year of life was evaluated.

METHODS

The study sample consisted of 105 preterm infants (postmenstrual age [PMA] at birth = 30.5 +/- 2.8 weeks [mean +/- SD]; birth weight = 1476 +/- 460 g; mean length of hospital stay = 41.6 +/- 31.4 days). All infants received a 5-minute sucking test at 34 and at 40 weeks PMA, with outcomes evaluated at 6 and/or 12 months corrected gestational age via the Bayley Scales of Infant Development.

RESULTS

As expected, 6- and 12-month values for the Psychomotor Developmental Index (PDI) and Mental Developmental Index (MDI) of the Bayley Scales of Infant Development were significantly below the normative levels established for infants delivered at term. A significant association between neonatal sucking pattern at 40 weeks PMA and developmental outcome at 12 months corrected gestational age was obtained. Each of the 3 simple sucking parameters evaluated (number of sucks, mean number of sucks per bursts and mean sucking pressure peaks), as well as a composite parameter (average of the respective parameter z-scores), was significantly related to both PDI and MDI at 12 months.

CONCLUSIONS

Multivariable models, adjusting for PMA at birth, length of hospital stay, and other predictors, affirmed that sucking performance at 40 weeks PMA was a significant, independent predictor of developmental status 1 year later. Standardization of an instrument for neonatal sucking assessment may offer a cost-effective early screening strategy for preterm infants at greatest risk for developmental delay.

The relationship between birth weight and feeding maturation in preterm infants

AIM

To report changes in ingestive behaviour from 35 to 40 weeks post-conceptual age and examine the association between birth weight and feeding maturation in preterm infants.

METHODS

One hundred and four preterm infants born 24 to 34 weeks gestational age were studied. Feeding maturation was assessed as the change from 35 to 40 weeks post-conceptual age in the number of sucks over 5 min, sucking bursts, sucks per burst, time between bursts and maximum pressure during a suck (Pmax). The association between birth weight and each sucking behaviour was examined after adjusting for potential confounders.

RESULTS

Significant changes in feeding maturation occurred between 35 and 40 weeks. Birth weight was positively associated with change in Pmax and change in number of sucks per burst for extremely premature infants born 24 to <29 weeks gestational age but not for very premature infants born >/=29 to 34 weeks. The association between birth weight and change in Pmax for extremely premature infants remained significant after adjustment (adjusted beta = 0.128 mmHg increase in change in maximum sucking pressure per every 1 g of birth weight, 95% CI = 0.017, 0.239, p = 0.03).

CONCLUSION

Birth weight is positively associated with maturation in maximum sucking pressure among infants born extremely premature.

Positive effect of NICU admission on breastfeeding of preterm US infants in 2000 to 2003

OBJECTIVE

We hypothesized that neonatal intensive care unit (NICU) admission reduces breastfeeding in a recent population of US infants, adjusting for confounding factors.

STUDY DESIGN

Using pregnancy risk assessment monitoring system data from 27 states for the years 2000 to 2003, we determined the relationship between breastfeeding and gestational age (GA) stratified by NICU status. We fitted a proportional odds model for breastfeeding duration as a function of NICU status adjusted for other covariates. SAS 9.1.3 and SUDAAN 9.0 were used for the weighted analyses.

RESULT

In total 138 359 surveys, including 29 940 NICU-admitted infants, were analyzed. A total of 73% of mothers of nonadmitted infants initiated breastfeeding vs 70% of mothers of NICU-admitted infants. Mothers of GA <38 weeks NICU-admitted infants were 34% more likely to initiate breastfeeding and 21% more likely to breastfeed for 4 weeks than were mothers of nonadmitted preterm infants (P<0.001). However, mothers of term NICU-admitted infants were less likely to initiate and continue breastfeeding to 4 weeks than were mothers of term nonadmitted infants (P<0.001). Adjusting for GA, race, maternal age, maternal education, mode of delivery and Medicaid status, NICU admission was associated with increasing duration of breastfeeding (OR 1.10, CI 1.03, 1.17). Compared with mothers of term infants, mothers of <32-week infants were 40% more likely to continue breastfeeding for 4 weeks, mothers of 32 to 34 week infants were 13% less likely to continue and mothers of 35-37 week infants were 22% less likely to continue for at least 4 weeks (P<0.001).

CONCLUSION

NICU admission is now a positive influence on breastfeeding continuation, improving the overall likelihood by 10%. Mothers of preterm NICU-admitted infants were more likely than mothers of nonadmitted infants to continue breastfeeding for 4 weeks, while mothers of term NICU-admitted infants were less likely to continue. Breastfeeding support should be enhanced for term and late preterm infants.

[Development of sucking rhythm and the influence of stimulation in premature infants]

BACKGROUND

The sucking development pattern of the preterm newborn (PTNB) in the neonatal period is important for an effective sucking and oral motor development. The establishment of a safe and efficient feeding in pre-term newborns is related to a rhythmic and coordinated sucking. Nonnutritive sucking stimulation can have an influence on the development of sucking and the development of sucking rhythm of pre-term newborns.

AIM

To analyze the development of the sucking rhythm, in non-nutritive and nutritive sucking in preterm newborns, as a consequence of non-nutritive sucking stimulation and in terms of corrected gestational age.

METHOD

95 preterm newborns randomly divided in three groups: Group 1, control group (35 PTNB), did not receive non-nutritive sucking stimulation; Group 2 (30 PTNB), received non-nutritive sucking stimulation using an orthodontic pacifier for premature infants (Nuk); and Group 3 (30 PTNB), received non-nutritive sucking stimulation using a gloved finger.

RESULTS

The mean gestational age was of 30.5 weeks (+/- 1.57), the mean corrected gestational age at the moment of enrollment in the study was of 31.6 weeks (+/- 1.31), and the mean birth weight was of 1.390 grams, with no statistical differences between the groups. The number of sucking bursts and pauses per minute increased by 0.16 per week and the duration of the bursts by 0.81 seconds; the duration of pauses decreased by 3.8 seconds per week while the number of sucks/second was constant, 1.15 and 0.95 for non-nutritive and nutritive sucking, respectively. No statistically significant differences were found between the groups for any of the studied variables.

CONCLUSION

The stimulation of non-nutritive suction in preterm newborns did not modify the post-natal development of sucking rhythm. The process of maturation, represented by the corrected gestational age, was considered the most responsible factor for this process.

Factors prolonging length of stay in the cardiac intensive care unit following the arterial switch operation

The arterial switch operation has become the preferred procedure for surgical management of transposition, defined on the basis of concordant atrioventricular and discordant ventriculo-arterial connections. We conducted a retrospective evaluation of our experience in 61 infants with this segmental combination, seen from January, 1997, to July, 2003, in order to determine the factors that are associated with a prolonged postoperative course. Factors independently associated with a prolonged postoperative stay in the cardiac intensive care unit included prematurity, difficulty in feeding, capillary leak, need for preoperative inotropic support, and postoperative infectious complications. Future research is warranted designed to minimize the impact of capillary leak and postoperative infectious complications. In addition, based on these results, our practice has evolved to initiate enteral feedings in the preoperative period if feasible, with such enteral feedings resumed as soon as possible following surgery.

Psychometric characteristics of the Neonatal Oral-Motor Assessment Scale in healthy preterm infants

We examined the reliability, validity, and responsiveness of the Neonatal Oral-Motor Assessment Scale (NOMAS) in healthy preterm infants. Feeding records of 147 infants (71 males, 76 females; gestational age [GA] <or= 36 wks), taken from the day bottle-feeding was initiated to the day the infants were discharged, were used to examine the psychometric properties of the normal and disorganized categories of the NOMAS. The infants, with or without experience of breastfeeding, were all fed by bottle, with either formula and/or breast milk. GA ranged from 24 to 35.9 weeks (mean 29.7 wks, SD 2.7) and birthweight ranged from 470 g to 2570 g (mean 1251.1g, SD 425.9). Postmenstrual age (PMA) at the starting point of bottle-feeding ranged from 29.4 to 40.1 weeks (mean 33.8 wks, SD 1.7). We found that the NOMAS had satisfactory internal consistency (Cronbach's alpha >0.70) in the normal category for 32 to 35 weeks'PMA. Moderate correlations were found between scores on the NOMAS and feeding performance for all age groups except for PMA of >or= 36 weeks (absolute Spearman's r(s)=0.51-0.69), indicating acceptable convergent validity. The NOMAS demonstrated moderate responsiveness to changes in oral-motor skills in every 2-week period, ranging from 32 to 36 weeks'PMA (standard response mean greater than 0.5). This study demonstrated that the normal and disorganized categories of the NOMAS are useful, with acceptable psychometric properties, in assessing oral-motor function in preterm infants aged 32 to 35 weeks'PMA. Future research on infants with abnormal oral-motor skills is needed to further validate psychometric properties of the dysfunction category of the NOMAS.

Predictors of nutritive sucking in preterm infants

OBJECTIVE

The purposes of this analysis were to determine how select characteristics of nutritive sucking (number of sucks, sucks/burst, and sucks/minute) change over time and to examine the effect of select factors (morbidity, maturity, prefeeding behavior state, and feeding experience) on those changes.

STUDY DESIGN

A longitudinal, non-experimental study was conducted in a Level 3 neonatal intensive care unit using a convenience sample of 88 preterm infants. Statistical analyses were performed using a repeated-measures mixed-model in SAS.

RESULTS

Sucking activity (number of sucks, sucks/burst, and sucks/minute) was predicted by morbidity, maturity, feeding experience and prefeeding behavior state. Experience at oral feeding had the greatest effect on changes in the number of sucks, suck/burst and sucks/minute.

CONCLUSION

Experience at feeding may result in more rapid maturation of sucking characteristics.

Immature sucking patterns in infants of mothers with diabetes

OBJECTIVE

To evaluate immaturity of sucking patterns of infants of mothers with diabetes.

STUDY DESIGN

Term infants born to mothers with gestational diabetes mellitus (16 mothers managed with insulin and 31 with diet alone) were compared with 55 matched healthy infants (control group). Sucking patterns were recorded and analyzed for number of sucks and bursts and averages maximum suck pressure, number of sucks per burst, suck width, and time between bursts. The measurements were made for feedings of 5 minutes duration with Kron's Nutritive Sucking Apparatus on the third day of life.

RESULTS

Relative to the control group, newborns of the insulin-treated mothers averaged 5.2 fewer bursts and 42 fewer sucks (P = .013 and P = .04, respectively). No differences were noted for other variables tested. There were no differences in sucking patterns between newborns of diet-managed mothers and control newborns.

CONCLUSION

Poorer sucking patterns were found among infants of insulin-managed mothers with diabetes. The present findings indicate some degree of neurologic immaturity during the early neonatal period.

Changes in sucking performance from nonnutritive sucking to nutritive sucking during breast- and bottle-feeding

Our aim was to obtain a better understanding of the differences between breast-feeding and bottle-feeding, particularly with regard to how sucking performance changes from nonnutritive sucking (NNS) to nutritive sucking (NS). Twenty-two normal term infants were studied while breast-feeding at 4 and 5 d postpartum. Five of the 22 infants were exclusively breast-fed, but we tested the other 17 infants while breast-feeding and while bottle-feeding. Before the milk ejection reflex (MER) occurs, little milk is available. As such, infants perform NNS before MER. For bottle-feeding, a one-way valve was affixed between the teat and the bottle so that the infants needed to perform NNS until milk flowed into the teat chamber. At the breast, the sucking pressure (-93.1 +/- 28.3 mm Hg) was higher during NNS compared with NS (-77.3 +/- 27.0 mm Hg). With a bottle, the sucking pressure was lower during NNS (-27.5 +/- 11.2 mm Hg) compared with NS (-87.5 +/- 28.5 mm Hg). Sucking frequency was higher and sucking duration was shorter during NNS compared with that during NS both at the breast and with a bottle. There were significant differences in the changes of sucking pressure and duration from NNS to NS between breast- and bottle-feeding. The change in sucking pressure and duration from NNS to NS differed between breast-feeding and bottle-feeding. Even with a modified bottle and teats, bottle-feeding differs from breast-feeding.

Relationship of the first suck burst to feeding outcomes in preterm infants

OBJECTIVE

This study examined the relationship between the number of sucks in the first nutritive suck burst and feeding outcomes in preterm infants. The relationships of morbidity, maturity, and feeding experience to the number of sucks in the first suck burst were also examined.

METHODS

A non-experimental study of 95 preterm infants was used. Feeding outcomes included proficiency (percent consumed in first 5 min of feeding), efficiency (volume consumed over total feeding time), consumed (percent consumed over total feeding), and feeding success (proficiency >or=0.3, efficiency >or=1.5 mL/min, and consumed >or=0.8). Data were analyzed using correlation and regression analysis.

RESULTS AND CONCLUSIONS

There were statistically significant positive relationships between number of sucks in the first burst and all feeding outcomes-proficiency, efficiency, consumed, and success (r=0.303, 0.365, 0.259, and tau=0.229, P<.01, respectively). The number of sucks in the first burst was also positively correlated to behavior state and feeding experience (tau=0.104 and r=0.220, P<.01, respectively). Feeding experience was the best predictor of feeding outcomes; the number of sucks in the first suck burst also contributed significantly to all feeding outcomes. The findings suggest that as infants gain experience at feeding, the first suck burst could be a useful indicator for how successful a particular feeding might be.

Early discharge among late preterm and term newborns and risk of neonatal morbidity

Understanding how late preterm infants (34-36 completed weeks' gestation) are affected by discharge policies created for term infants (37-41 completed weeks' gestation) is essential for preventing postdischarge neonatal morbidity among late preterm infants. We analyzed linked birth certificate and hospital discharge data for Massachusetts between 1998 and 2002 to evaluate the risk of neonatal morbidity (defined as hospital readmission, observational stay, or both) between all vaginally delivered, live-born singleton late preterm and term infants. All infants were born at a Massachusetts hospital to a state resident and were discharged home early (<2-night hospital stay). We calculated crude and adjusted risk ratios using a modified Poisson regression and compared the timing and principal discharge diagnoses for those neonates who needed hospital readmission. Of the 1004 late preterm and 24,320 term infants in our study, 4.3% and 2.7% of infants, respectively, were either readmitted or had an observational stay. Late preterm infants were 1.5 times more likely to require hospital-related care and 1.8 times more likely to be readmitted than term infants. Among infants who were breastfed, late preterm infants were 1.8 times more likely than term infants to require hospital-related care and 2.2 times more likely to be readmitted. In contrast, no differences were found between late preterm and term infants who were not breastfed. Jaundice and infection accounted for the majority of readmissions. Our findings suggest that late preterm infants discharged early experience significantly more neonatal morbidity than term infants discharged early; however, this may be true only for breastfed infants. Evidence-based recommendations for appropriate discharge timing and postdischarge follow-up for these late preterm infants are needed to prevent neonatal morbidity.

Development of preterm infants: feeding behaviors and brazelton neonatal behavioral assessment scale at 40 and 44 weeks' postconceptional age

The purpose of this study was twofold: (1) to explore potential changes in the Brazelton Neonatal Behavioral Assessment Scale (BNBAS) from 40 to 44 weeks postconceptional age (PCA) and (2) to determine the relationship between the BNBAS scores and feeding behaviors in preterm infants at 40 and 44 weeks PCA. The BNBAS and sucking behavior measurements were completed on 104 preterm infants at 40 and 44 weeks PCA. The Orientation (p = .001), Motor (p = .001), Range of State (p = .001), Autonomic Regulation (p = .01), and Reflexes (p = .00) clusters were significantly more mature at 44 weeks PCA than at 40 weeks. Infants that were extremely early born (n = 24) had a significantly larger change in BNBAS scores over time as compared to the more mature preterm infants (n = 77), largely catching up with their more mature preterm counterparts. At 40 and 44 weeks PCA, the BNBAS cluster scores for orientation (p = .02), motor (p = .048), range of state (p = .048), and regulation of state (p < .001) were significantly related to the average maximum pressure, adjusted for gestational age and weeks PCA. Significant neurobehavioral maturation takes place between 40 and 44 weeks PCA in preterm infants, with the greatest changes occurring in the most preterm infants. These findings highlight the relationship between neurobehavioral maturation and feeding behaviors.

Prediction of Feeding Performance in Preterm Infants

A nonexperimental study with a sample of 95 preterm infants was used to develop a model of feeding performance outcomes (proficiency, percent of prescribed volume consumed, and efficiency) using feeding readiness indicators (morbidity, maturity, behavior state at feeding start, and feeding experience). All readiness indicators were related to each other. In particular, there was a strong relationship between maturity and feeding experience. Morbidity only had an effect on efficiency; the most ill infants were less efficient feeders. Behavior state affects all feeding outcomes in a linear fashion; more awake and alert infants had better feeding performance outcomes. The effect of experience and maturity on the outcomes is more complex because of the relationship between the two. Experience has a greater effect as the infant matures, and as the infant matures, the amount of experience increases. Successful feeding requires maturity as well as experience.