Sucking behaviour in infants born preterm and developmental outcomes at primary school age.

AIM: To determine the association between sucking in infants born preterm and developmental outcomes at 5 years. METHOD: Thirty-four infants were included (mean gestational age 30wks 4d, mean birthweight 1407g). The Neonatal Oral-Motor Assessment Scale was used longitudinally from 37 to 50 weeks postmenstrual age. At 5 years, we assessed motor skills, intelligence, language, verbal memory, and behavioural problems. Linear regression analyses were performed to test whether aspects of sucking behaviour predicted these developmental outcomes. Where linear regression was not appropriate, Spearman's correlation coefficients were calculated between sucking and developmental outcomes. RESULTS: Sucking was associated with total motor skills (B [unstandardized correlation coefficient for normally distributed data]=22.66, 95% confidence interval [CI] 6.61 to 38.71), balance (Spearman's ρ=0.64, p<0.001), total intelligence (B=-1.16, 95% CI -1.89 to -0.44, B=10.48, 95% CI 0.39 to 20.71, B=-2.22, 95% CI -3.42 to -1.02), verbal intelligence (B=-0.95; 95% CI -1.83 to -0.07, B=-2.02; 95% CI -3.55 to -0.49), performance intelligence (B=-1.34, 95% CI -2.13 to -0.54, B=12.36, 95% CI 1.13 to 23.60, B=-2.37, 95% CI -3.75 to -0.96), and language (B=-1.78, 95% CI -3.36 to -0.19). All associations were in the same direction: the better the sucking, the higher the test scores. Verbal memory and behavioural problems were not associated with sucking. INTERPRETATION: Abnormal sucking between 42 weeks and 50 weeks postmenstrual age may reflect abnormal neurological functioning in children born preterm.

Exposure to texture of foods for 8-month-old infants: Does the size of the pieces matter?

This study examined the effect of meals varying in amount, size, and hardness of food pieces on the development of the chewing capabilities of 8-month-old infants. The study also examined changes in shivering, gagging, coughing, choking, and their ability to eat from a spoon. In an in-home setting two groups were given commercially available infant meals and fruits, purees with either less, smaller and softer or more, larger and harder pieces. Both groups were given these foods for 4 weeks and were monitored several times during this period. After the 4-week exposure period infants in both groups were given the same five test foods. Structured questionnaires with questions on eating behavior and the child's development were conducted 6 times in the 4 to 12-month period and video analyses of feedings were conducted 4 times between 8 and 9 months. After the 4-week exposure period, the group that had been exposed to the foods with more, larger and harder pieces showed a significantly higher rating for chewing a piece of carrot and potato for the first time, but not for a piece of banana nor for mashed foods. Shivering, gagging, coughing, choking, and ability to eat from a spoon were not different between the two groups. These results contribute to the insight that exposure to texture is important for young children to learn how to handle texture. PRACTICAL APPLICATIONS: (a) The study shows the feasibility of testing the effects of texture interventions on chewing capability and oral responses such as gagging, coughing, and choking in infants. (b) The study contributes to the insight that exposure to food texture to learn how to handle texture is important for infants and showed that exposing children to a higher amount of larger pieces improves their chewing capability for a piece of carrot and potato, at least immediately after the intervention.

New scoring system improves inter-rater reliability of the Neonatal Oral-Motor Assessment Scale.

AIM: The Neonatal Oral-Motor Assessment Scale (NOMAS) is a standardised tool to assess sucking patterns in infants to 48 weeks of postmenstrual age (PMA). In the Netherlands, the interpretation of specific NOMAS items has evolved, leading to a new scoring system. Recent research using the NOMAS describes a way of clustering the most frequent items, and the aim of this study was to determine whether those changes improved the inter-rater reliability. METHODS: The inter-rater reliability was tested by two NOMAS-certified therapists who scored 120 video recordings of 40 preterm infants, admitted to the University Hospital of Düsseldorf, Germany, at 34, 37 and 44 weeks PMA, for normal, disorganised and dysfunctional diagnosis. The NOMAS comprised 28 items and five clusters of items. RESULTS: The therapists agreed on the level of diagnoses for 116 of 120 recordings (Cohen's Κ 0.90), on an item level for 107 of 120 recordings (Cohen's Κ 0.78) and on a cluster level for 108 of 120 recordings (Cohen's K 0.90). CONCLUSION: The new scoring system improved the inter-rater reliability of the NOMAS on all levels, highlighting the importance of NOMAS user having a clear understanding on how to interpret and score each item.

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.

Uncoordinated sucking patterns in preterm infants are associated with abnormal general movements.

OBJECTIVE: To examine the association between sucking patterns and the quality of fidgety movements in preterm infants. STUDY DESIGN: We studied the sucking patterns and fidgety movements of 44 preterm infants (gestational age <35 weeks) longitudinally from 34 weeks' postmenstrual age up to 14 weeks postterm. We used the Neonatal Oral-Motor Assessment Scale during feeding and scored the sucking patterns as normal or abnormal. Abnormal sucking patterns were categorized into arrhythmic sucking and uncoordinated sucking. At 14 weeks postterm, we scored the quality of fidgety movements from videotapes as normal, abnormal, or absent. RESULTS: The postmenstrual age at which sucking patterns became normal (median, 48 weeks; range, 34 to >50 weeks) was correlated with the quality of fidgety movements (Spearman ρ = -0.33; P = .035). The percentage per infant of normal and uncoordinated sucking patterns was also correlated with the quality of fidgety movements (ρ = 0.31; P = .048 and ρ = -0.33; P = .032, respectively). Infants with uncoordinated sucking patterns had a higher rate of abnormal fidgety movements (OR, 7.5; 95% CI, 1.4-40; P = .019). CONCLUSION: The development of sucking patterns in preterm infants was related to the quality of fidgety movements. Uncoordinated sucking patterns were associated with abnormal fidgety movements, indicating that uncoordinated sucking, swallowing, and breathing may represent neurologic dysfunction.

The development of sucking patterns in preterm, small-for-gestational age infants.

OBJECTIVE: To determine whether the development of sucking patterns in small-for-gestational age (SGA) preterm infants differs from appropriate-for-gestational age (AGA) preterm infants. STUDY DESIGN: We assessed sucking patterns in 15 SGA and 34 AGA preterms (gestational age

Development of sucking patterns in pre-term infants with bronchopulmonary dysplasia.

BACKGROUND: Pre-term infants with bronchopulmonary dysplasia (BPD) are at risk of acquiring brain abnormalities. Combined with ongoing breathing difficulties, this may influence the development of their sucking patterns. OBJECTIVE: To determine the longitudinal development of sucking patterns from birth until 10 weeks' post-term age in pre-term infants with and without BPD. METHODS: The sucking patterns of 16 pre-term infants with BPD and 15 pre-term infants without BPD were prospectively assessed with the Neonatal Oral-Motor Assessment Scale. The infants were matched for gestational age (<30 weeks). We recorded approximately 12 feeding episodes per infant, from 34 until 50 weeks' post-menstrual age. We diagnosed the infants' sucking patterns as normal, dysfunctional, or disorganized. Then, we examined the development of the sucking patterns in relation to relevant clinical characteristics. RESULTS: Thirty (21%) of 142 feeding episodes of the pre-term infants with BPD and 36 (23%) of 156 of those without BPD were diagnosed as normal (non-significant). Of the abnormal patterns, 3 were diagnosed as dysfunctional and 229 as disorganized. Before term-equivalent age, definitely abnormal sucking patterns were more prevalent in the pre-term infants with BPD than in those without BPD: 69 (49%) and 47 (30%) episodes, respectively (χ(2) = 10.7, p < 0.01). In particular, the abnormal patterns including the item 'incoordination', defined as the inability to coordinate sucking and swallowing with breathing, were more prevalent: 36 and 15%, respectively (χ(2) = 6.37, p < 0.05). There was no difference between the two groups regarding the age at which they acquired normal sucking patterns. Relevant clinical characteristics did not influence the development of the sucking patterns. CONCLUSIONS: The developmental characteristic of sucking patterns in infants with BPD was that these infants were unable to coordinate swallowing with breathing. This was the case especially prior to term-equivalent age; after term-equivalent age, the development of sucking closely resembled that of pre-term infants without BPD.

Sucking patterns in fullterm infants between birth and 10 weeks of age.

OBJECTIVE: Coordinating sucking, swallowing and breathing to achieve effective sucking is a complex process and even though sucking is essential for nutrition, little is known about sucking patterns after birth. Our objective was to study sucking patterns in healthy fullterm infants and to describe the age-specific variations. METHOD: We studied the sucking patterns of 30 healthy, fullterm infants longitudinally from 2 or 3 days after birth to 10 weeks of age. During this time we recorded five to seven feeding episodes that we assessed off-line with the Neonatal Oral-Motor Assessment Scale (NOMAS). RESULTS: We found a normal sucking pattern on the second or third day after birth in 27 out of 30 infants. During the following weeks we found abnormal sucking patterns in 23 out of 171 feeding episodes (14%) and normal patterns in 148 episodes (86%). Altogether, between 38 and 50 weeks' postmenstrual age (10 weeks after birth), 10 infants displayed a deviating, arrhythmical sucking pattern. Dysfunctional sucking patterns and problems of coordinating sucking, swallowing and breathing did not occur. Birth weight, gestational age, type of labour and gender did not influence sucking patterns. Arrhythmical sucking was seen more often in bottle-fed infants. CONCLUSION: Our study demonstrated that practically all healthy fullterm infants started off with a normal sucking pattern soon after birth. One-third of the infants displayed one or more deviating episodes up to the age of 10 weeks. Apart from bottle-feeding, no other factors were found that influenced sucking patterns.

The reliability of the Neonatal Oral-Motor Assessment Scale.

OBJECTIVES: Sucking problems in preterm infants can be specified by means of visual observation. The Neonatal Oral-Motor Assessment Scale (NOMAS) is the visual observation method most commonly used to assess the non-nutritive sucking (NNS) and nutritive sucking (NS) skills of infants up to approximately 8 weeks postterm. During the first 2 min of a regular feeding the infant's sucking skill is assessed, either immediately or on video. Although NOMAS has been used since 1993, little is known about the method's reliability. The aim of our study was to determine the test-retest and inter-rater reliability of NOMAS. METHODS: The 75 infants included in this study were born at 26-36 weeks postmenstrual age (PMA). Four observers participated in the study. They were trained and certified to administer NOMAS in the Netherlands by M.M. Palmer between 2000 and 2002. RESULTS: We found the test-retest agreement of NOMAS to be 'fair' to 'almost perfect' (Cohen's kappa [kappa] between 0.33 and 0.94), whereas the inter-rater agreement with respect to the diagnosis was 'moderate' to 'substantial' (Cohen's kappa, between 0.40 and 0.65). As a diagnostic tool, however, the current version of NOMAS cannot be used for both full-term and preterm infants. For a measuring instrument such as NOMAS, one should aim at reliability coefficients for inter-rater and test-retest agreement of at least 0.8. A Cohen's kappa of 0.6 or less we find unacceptable. Nonetheless, by observing sucking and swallowing according to a protocol much useful information can be gathered about the development of an infant's sucking skills. For instance, whether the infant is able to co-ordinate sucking and swallowing, whether the infant can maintain sucking, swallowing and breathing during the continuous phase and whether the infant is able to suck rhythmically with equally long bursts. In addition, NOMAS offers useful aids for intervention. CONCLUSIONS: NOMAS should be re-adjusted in order to improve inter-rater agreement, and at the same time current insights into the development of sucking and swallowing should be incorporated in the method.