Understanding language and cognitive deficits in very low birth weight children

Early language processing efficiency and pre-literacy outcomes in children born full term and preterm

Language processing efficiency-that is, the skill at processing language in real time-assessed in toddlerhood is associated with later language outcomes in children born full term (FT) and preterm (PT) during school age. No studies to date have assessed patterns of relations between early language processing efficiency and pre-literacy skills, such as print knowledge and phonological awareness, and whether relations are similar in FT and PT children. In this study, participants (N = 94, 49 FT and 45PT) were assessed in the looking-while-listening (LWL) task at 18 months of age (corrected for degree of prematurity), deriving measures of processing speed and accuracy. At 4½ years of age, children were assessed on standardized tests of print knowledge, phonological awareness, and expressive language. Processing speed and accuracy predicted both pre-literacy outcomes (r2 change = 7.8%-19.5%, p < .01); birth group did not moderate these effects. Relations were significantly reduced when controlling for expressive language. Thus, early language processing efficiency supports later expressive language abilities, which in turn supports developing pre-literacy skills. Processing speed and phonological awareness were also directly related, indicating an independent role for processing speed in literacy development. Mediation effects were not moderated by birth group, suggesting a similar developmental pathway in FT and PT children.

Interventions and their efficacy in supporting language development among preterm children aged 0-3 years - A systematic review

BACKGROUND

Preterm children have a higher risk for linguistic delays than full-term infants but are rarely provided with language intervention at an early age. Knowledge on early language interventions targeted to preterm children is scarce, and efficacy of the interventions is rarely reported.

AIM

This systematic review aims to identify interventions for preterm children aged 0-3 years with at least one language outcome. Efficacy of the interventions and quality of the study reports were evaluated.

STUDY DESIGN

The article search was carried out in six databases: EBSCOhost, Scopus, ERIC, LLBA, Ovid, and Web of Science. Effect sizes (Hedges' g) were calculated for language outcomes. Quality of the study reports was assessed using the levels of evidence system by the American Speech-Language-Hearing Association.

RESULTS

The 28 studies identified were divided into three groups: interventions at Neonatal Intensive Care Unit, interventions during the first year, and interventions during the second and/or third years. Most of the interventions focused on supporting child-care and general development. Of the interventions, 61 % were efficacious in supporting language development of preterm children. The most promising results regarding efficacy were interventions conducted during the second and/or third years (80 %). Quality of the reports varied from high/good (89 %) to low (11 %).

CONCLUSION

The 28 existing studies provide limited evidence of the efficacy of very early interventions promoting language development of preterm children. However, especially the results for interventions conducted during the second and/or third years show promise. More studies, particularly language-focused interventions with longer follow-ups, are needed.

Through Thick and Thin: Gesture and Speech Remain as an Integrated System in Atypical Development

Gesture and speech are tightly linked and form a single system in typical development. In this review, we ask whether and how the role of gesture and relations between speech and gesture vary in atypical development by focusing on two groups of children: those with peri- or prenatal unilateral brain injury (children with BI) and preterm born (PT) children. We describe the gestures of children with BI and PT children and the relations between gesture and speech, as well as highlight various cognitive and motor antecedents of the speech-gesture link observed in these populations. We then examine possible factors contributing to the variability in gesture production of these atypically developing children. Last, we discuss the potential role of seeing others' gestures, particularly those of parents, in mediating the predictive relationships between early gestures and upcoming changes in speech. We end the review by charting new areas for future research that will help us better understand the robust roles of gestures for typical and atypically-developing child populations.

Listening Preference for Child-Directed Speech Versus Time-Reversed Speech in Moderate-Preterm Infants Compared to Full-Term Infants

PURPOSE

The purpose of the present study was to examine whether there is a listening preference for child-directed speech (CDS) over backward speech in moderate-preterm infants (MPIs).

METHOD

Eighteen MPIs of gestational age of 32.0 weeks (range: 32-34.06 weeks), chronological age of 8.09 months, and maturation age of 6.48 months served as the experimental group. The two control groups consisted of a total of 36 infants-20 full-term infants matched for chronological age and 16 full-term infants matched for maturation age. The infants were tested using the central fixation procedure and were presented with 16 trials of CDS and backward speech. A follow-up was conducted 5 years after the initial experiment using a developmental and a five-item parent questionnaire.

RESULTS

MPIs did not demonstrate a preference for CDS over backward speech, whereas both control groups demonstrated a listening preference for CDS over backward speech. MPIs showed a delayed use of first words and word combinations and lower scores on the five-item questionnaire compared to term infants. Twelve MPIs (67%) did not demonstrate a preference for CDS over backward speech. Four of them (33%) were later diagnosed with neurodevelopmental disorders.

CONCLUSIONS

The lack of preference for CDS over backward speech in the MPIs group suggests delayed developmental pattern of speech processing compared to full-term peers. Delays in neurological maturation as well as listening experience in an unregulated environment outside the uterus during a sensitive period of brain development may affect the recognition of phonological and prosodic patterns that support listening preference for speech over backward speech.

A Role for Visual Memory in Vocabulary Development: A Systematic Review and Meta-Analysis

Although attention and early associative learning in preverbal children is predominantly driven by rapid eye-movements in response to moving visual stimuli and sounds/words (e.g., associating the word "bottle" with the object), the literature examining the role of visual attention and memory in ongoing vocabulary development across childhood is limited. Thus, this systematic review and meta-analysis examined the association between visual memory and vocabulary development, including moderators such as age and task selection, in neurotypical children aged 2-to-12 years, from the brain-based perspective of cognitive neuroscience. Visual memory tasks were classified according to the visual characteristics of the stimuli and the neural networks known to preferentially process such information, including consideration of the distinction between the ventral visual stream (processing more static visuo-perceptual details, such as form or colour) and the more dynamic dorsal visual stream (processing spatial temporal action-driven information). Final classifications included spatio-temporal span tasks, visuo-perceptual or spatial concurrent array tasks, and executive judgment tasks. Visuo-perceptual concurrent array tasks, reliant on ventral stream processing, were moderately associated with vocabulary, while tasks measuring spatio-temporal spans, associated with dorsal stream processing, and executive judgment tasks (central executive), showed only weak correlations with vocabulary. These findings have important implications for health professionals and researchers interested in language, as they advocate for the development of more targeted language learning interventions that include specific and relevant aspects of visual processing and memory, such as ventral stream visuo-perceptual details (i.e., shape or colour).

Associations between early efficiency in language processing and language and cognitive outcomes in children born full term and preterm: similarities and differences

Associations between children's early language processing efficiency and later verbal and non-verbal outcomes shed light on the extent to which early information processing skills support later learning across different domains of function. Examining whether the strengths of associations are similar in typically developing and at-risk populations provides an additional lens into the varying routes to learning that children may take across development. In this follow-up study, children born full-term (FT, n = 49) and preterm (PT, n = 45, ≤32 weeks gestational age, birth weight <1800 g) were assessed in the Looking While Listening (LWL) task at 18 months (corrected for degree of prematurity in PT group). This eye-tracking task assesses efficiency of real-time spoken language comprehension as accuracy and speed (RT) of processing. At 4 ½ years, children were assessed on standardized tests of receptive vocabulary, expressive language, and non-verbal IQ. Language processing efficiency was associated with both language outcomes (r2-change: 7.0-19.7%, p < 0.01), after covariates. Birth group did not moderate these effects, suggesting similar mechanisms of learning in these domains for PT and FT children. However, birth group moderated the association between speed and non-verbal IQ (r2-change: 4.5%, p < 0.05), such that an association was found in the PT but not the FT group. This finding suggests that information processing skills reflected in efficiency of real-time language processing may be recruited to support learning in a broader range of verbal and non-verbal domains in the PT compared to the FT group.

Handedness in low-birthweight children: Insights in lateralization

Low-birthweight (LBW) children (n = 96) weighing less than 2.5 kg at birth and normal birthweight (NBW) children (n = 96) from Delhi, India, between the ages of 5 and 12 years were assessed for intelligence with Ravens Colored Progressive Matrices (RCPM), their handedness and hand proficiency for unimanual and bimanual performance. The objective was to know if there is a relation between birthweight and the development of handedness. Compared with NBW children, the LBW group had lower percentile scores for the RCPM. The LBW children were less lateralized than the NBW children in the hand preference test. The LBW children were faster than the NBW for sorting objects with each hand separately, but they were slower in the bimanual envelope task. This indicates a delay in interhemispheric transfer and the development of the corpus callosum that connects the cerebral hemispheres to enable bimanual coordination. In the absence of more direct evidence, hand skill was used as an index of the extent of lateralized control for performance. Findings indicate a relation between birthweight and lateralization in children tested for hand preference.

Therapeutic Interventions in Rat Models of Preterm Hypoxic Ischemic Injury: Effects of Hypothermia, Caffeine, and the Influence of Sex

Infants born prematurely have an increased risk of experiencing brain injury, specifically injury caused by Hypoxia Ischemia (HI). There is no approved treatment for preterm infants, in contrast to term infants that experience Hypoxic Ischemic Encephalopathy (HIE) and can be treated with hypothermia. Given this increased risk and lack of approved treatment, it is imperative to explore and model potential treatments in animal models of preterm injury. Hypothermia is one potential treatment, though cooling to current clinical standards has been found to be detrimental for preterm infants. However, mild hypothermia may prove useful. Caffeine is another treatment that is already used in preterm infants to treat apnea of prematurity, and has shown neuroprotective effects. Both of these treatments show sex differences in behavioral outcomes and neuroprotective effects, which are critical to explore when working to translate from animal to human. The effects and research history of hypothermia, caffeine and how sex affects these treatment outcomes will be explored further in this review article.

Eye tracking based assessment of lexical processing and early lexical development in very preterm children

BACKGROUND

Associations between lexical processing and lexical development during the second year of life have been little studied in preterm children.

AIMS

To evaluate associations between lexical processing at 18 months and lexical development between 12 and 18 months in very preterm children.

STUDY DESIGN

Correlational study.

SUBJECTS

25 Finnish-speaking children born <32 gestational weeks.

OUTCOME MEASURES

Lexical processing (reaction time RT; correct looking time CLT) was measured with an eye tracking technology-based task at 18 months' corrected age. Lexical development was measured longitudinally at 12-, 15- and 18-months' corrected age using the following screening instruments: the short form version of the MacArthur Communicative Development Inventories and the Communication and Symbolic Behavior Scale: Infant-Toddler Checklist.

RESULTS

The longer the RT of the child, the weaker expressive skills the child had at 12 and 15 months (correlations coefficient values -0.45 to -0.51). The more the child looked at the target image compared to the distractor (CLT), the stronger expressive skills the child had at 18 months (r = 0.45-0.52). A linear regression model with RT and gender as independent variables explained 33 % of the variance in lexical skills at 18 months. A model with CLT explained 40 % of expressive skills at 18 months.

CONCLUSIONS

Lexical processing at 18 months was associated with expressive lexical development in very preterm children. The results suggest eye tracking technology based methods may have utility in the assessment of early lexical growth in preterm children, although further research is needed to assess psychometric properties and predictive value of the method.

Predicting risks of low birth weight in Bangladesh with machine learning

Background and objective

Low birth weight is one of the primary causes of child mortality and several diseases of future life in developing countries, especially in Southern Asia. The main objective of this study is to determine the risk factors of low birth weight and predict low birth weight babies based on machine learning algorithms.

Materials and methods

Low birth weight data has been taken from the Bangladesh Demographic and Health Survey, 2017–18, which had 2351 respondents. The risk factors associated with low birth weight were investigated using binary logistic regression. Two machine learning-based classifiers (logistic regression and decision tree) were adopted to characterize and predict low birth weight. The model performances were evaluated by accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve.

Results

The average percentage of low birth weight in Bangladesh was 16.2%. The respondent’s region, education, wealth index, height, twin child, and alive child were statistically significant risk factors for low birth weight babies. The logistic regression-based classifier performed 87.6% accuracy and 0.59 area under the curve for holdout (90:10) cross-validation, whereas the decision tree performed 85.4% accuracy and 0.55 area under the curve.

Conclusions

Logistic regression-based classifier provided the most accurate classification of low birth weight babies and has the highest accuracy. This study’s findings indicate the necessity for an efficient, cost-effective, and integrated complementary approach to reduce and correctly predict low birth weight babies in Bangladesh.

Gestational Age in Autistic Children and Adolescents: Prevalence and Effects on Autism Phenotype

Pre- and post-term children show increased autism risk. Little is known about gestational age (GA) prevalence among autistic children, and their respective autism phenotype. We compared prevalence of pre-, full- and post-term birth between a population-derived sample of N = 606 (137 females, 22.61%) autistic children and adolescents (mean age = 14.01, SD = 3.63, range 3–24) from the Netherlands Autism Register, and matched controls from the Dutch birth register. Autism phenotype and comorbid symptoms were assessed with the AQ-short and SDQ questionnaires. Using logistic regression, we found higher prevalence of pre- and post-term birth among autistic individuals but no phenotypical differences across GA groups. Autism risk was particularly elevated for post-term children, highlighting the need for closer investigation of autism on the whole GA range.

Parental Book-Reading to Preterm Born Infants in NICU: The Effects on Language Development in the First Two Years

Background: After preterm birth, infants are at high risk for delays in language development. A promising intervention to reduce this risk is represented by the exposure to parental voices through book-reading in Neonatal Intensive Care Units (NICU). This study investigated the possible advantages of book-reading to preterm neonates during their NICU stay on their subsequent language development. Methods: 100 families of preterm infants were recruited. The parents of 55 preterm infants (Reading Group) received a colored picture-book on NICU admission and were supported to read to their neonate as often as possible and to continue after hospital discharge. Forty-five infants (Control Group) were recruited before the beginning of the intervention. Infant language development was assessed with the Hearing and Language quotients of the Griffith Mental Development Scale at the corrected ages of 3, 6, 9, 12, 18 and 24 months. Results: Regardless of group membership, Hearing and Language mean quotients decreased between 9 and 18 months; nevertheless, this decrease was considerably reduced in the Reading group, compared to the Control Group. Conclusions: Reading in NICUs represents a suitable intervention that could positively influence language development and parent-infant relationships in preterm children. The study findings support its implementation as a preventive measure.

Preterm Birth and the Development of Visual Attention During the First 2 Years of Life: A Systematic Review and Meta-analysis

Importance

Preterm birth is associated with an increased risk for long-lasting attention deficits. Early-life markers of attention abnormalities have not been established to date but could provide insights into the pathogenesis of attention abnormalities and could help identify susceptible individuals.

Objective

To examine whether preterm birth is associated with visual attention impairments in early life, and if so, in which attention functions and at which developmental period during the first 2 years of life.

Data Sources

PubMed and PsycINFO were searched on November 17, 2019, to identify studies involving visual attention outcomes in infants born preterm vs full term.

Study Selection

Peer-reviewed studies from the past 50 years met the eligibility criteria if they directly assessed visual attention outcomes until the age of 2 years in generally healthy infants born preterm or full term. The selection process was conducted by 2 independent reviewers.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline was followed. Random-effects models were used to determine standardized mean differences. The risk of bias was assessed both within and between studies.

Main Outcomes and Measures

Five nascent indices of visual attention were analyzed, including very basic functions-namely, the abilities to follow and fixate on visual targets-and more complex functions, such as visual processing (ie, habituation), recognition memory (ie, novelty preference), and the ability to effortfully focus attention for learning.

Results

A total of 53 studies were included, with 69 effect sizes and assessing a total of 3998 infants (2047 born preterm and 1951 born full term; of the 3376 for whom sex was reported, 1693 [50.1%] were girls). Preterm birth was associated with impairments in various attention indices, including visual-following in infancy (Cohen d, -0.77; 95% CI, -1.23 to -0.31), latency to fixate (Cohen d, -0.18; 95% CI, -0.33 to -0.02), novelty preference (Cohen d, -0.20; 95% CI, -0.32 to -0.08), and focused attention (Cohen d, -0.28; 95% CI, -0.45 to -0.11). In the neonatal period, preterm birth was associated with superior visual-following (Cohen d, 0.22; 95% CI, 0.03 to 0.40), possibly owing to the additional extrauterine exposure to sensory stimulation. However, this early association waned rapidly in infancy (Cohen d, -0.77; 95% CI, -1.23 to -0.31).

Conclusions and Relevance

The findings suggest that preterm birth is associated with impingements to visual attention development in early life, as manifested in basic and then complex forms of attention. Advancements in neonatal care may underlie improvements found in the current era and accentuate several early protective factors.

The effects of prematurity and socioeconomic deprivation on early speech perception: A story of two different delays

There is evidence showing that both maturational and environmental factors can impact on later language development. On the one hand, preterm birth has been found to increase the risk of deficits in the preschool and school years. Preterm children show poorer auditory discrimination, reading difficulties, poor vocabulary, less complex expressive language and lower receptive understanding than their matched controls. On the other hand, socioeconomic status (SES) indicators (i.e., income, education and occupation) have been found to be strongly related to linguistic abilities during the preschool and school years. However, there is very little information about how these factors result in lower linguistic abilities. The present study addresses this issue. To do so, we investigated early speech perception in full and preterm infants from families classed as high or low SES. Seventy-six infants were followed longitudinally at 7.5, 9, 10.5 and 12 months of age. At each test point, three studies explored infants' phonetic, prosodic and phonotactic development respectively. Results showed no significant differences between the phonetic or the phonotactic development of the preterm and the full-term infants. However, a time-lag between preterm and full-term developmental timing for prosody was found. Socioeconomic status did not have a significant effect on prosodic development. Nonetheless, phonetic and phonotactic development was affected by SES, infants from lower SES showed phonetic discrimination of non-native contrast and a preference for high-probability sequences later than their more advantaged peers. Overall these results suggest that different constraints apply to the acquisition of different phonological subcomponents.

Frequency-following response among neonates with progressive moderate hyperbilirubinemia

OBJECTIVE

To evaluate the feasibility of auditory monitoring of neurophysiological status using frequency-following response (FFR) in neonates with progressive moderate hyperbilirubinemia, measured by transcutaneous (TcB) levels.

STUDY DESIGN

ABR and FFR measures were compared and correlated with TcB levels across three groups. Group I was a healthy cohort (n = 13). Group II (n = 28) consisted of neonates with progressive, moderate hyperbilirubinemia and Group III consisted of the same neonates, post physician-ordered phototherapy.

RESULT

FFR amplitudes in Group I controls (TcB = 83.1 ± 32.5µmol/L; 4.9 ± 1.9 mg/dL) were greater than Group II (TcB = 209.3 ± 48.0µmol/L; 12.1 ± 2.8 mg/dL). After TcB was lowered by phototherapy, FFR amplitudes in Group III were similar to controls. Lower TcB levels correlated with larger FFR amplitudes (r = -0.291, p = 0.015), but not with ABR wave amplitude or latencies.

CONCLUSION

The FFR is a promising measure of the dynamic neurophysiological status in neonates, and may be useful in tracking neurotoxicity in infants with hyperbilirubinemia.

Absence of neural speech discrimination in preterm infants at term-equivalent age

Children born preterm are at higher risk to develop language deficits. Auditory speech discrimination deficits may be early signs for language developmental problems. The present study used functional near-infrared spectroscopy to investigate neural speech discrimination in 15 preterm infants at term-equivalent age compared to 15 full term neonates. The full term group revealed a significantly greater hemodynamic response to forward compared to backward speech within the left hemisphere extending from superior temporal to inferior parietal and middle and inferior frontal areas. In contrast, the preterm group did not show differences in their hemodynamic responses during forward versus backward speech, thus, they did not discriminate speech from non-speech. Groups differed significantly in their responses to forward speech, whereas they did not differ in their responses to backward speech. The significant differences between groups point to an altered development of the functional network underlying language acquisition in preterm infants as early as in term-equivalent age.

Predicting text reading skills at age 8 years in children born preterm and at term

BACKGROUND

Children born preterm are at risk for developing reading difficulties and for decrements in other cognitive skills compared to children born at term.

AIMS

To assess how domains of function, often negatively impacted by preterm birth, predict reading development in children born preterm and at term.

STUDY DESIGN

Longitudinal descriptive cohort study.

SUBJECTS

Preterm (n = 48; gestational age 22-32 weeks, 30 males) and term (n = 41, 18 males) participants were assessed at age 6 years on a battery of verbal and non-verbal cognitive skills and reassessed at age 8 using the Gray Oral Reading Tests-5. Linear regressions assessed the contributions of phonological awareness, language, executive function, and non-verbal IQ at age 6 to reading outcome at age 8.

RESULTS

Children born preterm had lower scores than children born at term on all measures (Cohen's d from 0.46 to 1.08, all p < .05). Phonological awareness and language abilities predicted reading in both groups (accounting for 19.9% and 25.0% of variance, respectively, p < .001). Birth group did not moderate the association. By contrast, the association between executive function and non-verbal intelligence and reading outcome was moderated by birth group (interaction accounted for 3.9-6.7% of variance, respectively, p < .05). Positive predictions to reading from executive function and non-verbal IQ were found only in children born preterm.

CONCLUSIONS

Non-verbal cognitive skills improved the prediction of reading outcome only in the preterm group, suggesting that reading decrements represent a component of global deficits. These findings have implications for evaluation of children born preterm at school entry and treatment of reading difficulties.

Language in Preterm Born Children: Atypical Development and Effects of Early Interventions on Neuroplasticity

Predicting language performances after preterm birth is challenging. It is described in the literature that early exposure to the extrauterine environment can be either detrimental or advantageous for neurodevelopment. However, the emphasis mostly lies on the fact that preterm birth may have an unfavorable effect on numerous aspects of development such as cognition, language, and behavior. Various studies reported atypical language development in preterm born children in the preschool years but also in school-aged children and adolescents. This review gives an overview of the course of language development and examines how prematurity can lead to atypical linguistic performances. In this paper, we mainly focus on environmental and neurophysiological factors influencing preterm infant neuroplasticity with potential short- and long-term effects on language development. Further research, however, should focus on examining the possible benefits that early exposure might entail.

Nurturing the preterm infant brain: leveraging neuroplasticity to improve neurobehavioral outcomes

An intrinsic feature of the developing brain is high susceptibility to environmental influence-known as plasticity. Research indicates cascading disruption to neurological development following preterm (PT) birth; yet, the interactive effects of PT birth and plasticity remain unclear. It is possible that, with regard to neuropsychological outcomes in the PT population, plasticity is a double-edged sword. On one side, high plasticity of rapidly developing neural tissue makes the PT brain more vulnerable to injury resulting from events, including inflammation, hypoxia, and ischemia. On the other side, plasticity may be a mechanism through which positive experience can normalize neurological development for PT children. Much of the available literature on PT neurological development is clinically weighted and focused on diagnostic utility for predicting long-term outcomes. Although diagnostic utility is valuable, research establishing neuroprotective factors is equally beneficial. This review will: (1) detail specific mechanisms through which plasticity is adaptive or maladaptive depending on the experience; (2) integrate research from neuroimaging, intervention, and clinical science fields in a summary of findings suggesting inherent plasticity of the PT brain as a mechanism to improve child outcomes; and (3) summarize how responsive caregiving experiences situate parents as agents of change in normalizing PT infant brain development.

Does early object exploration support gesture and language development in extremely preterm infants and full-term infants?

BACKGROUND

An increasing body of research on typically and atypically developing infants has shown that motor skills play an important role in language development. To date, however, the role of specific object exploration skills for early gesture and vocabulary development has not been investigated in extremely low gestational age infants (ELGA, GA < 28 weeks), who are at greater risk for motor and language delays than full-term (FT) infants.

PURPOSE

This longitudinal study examined relations between 6-month active exploratory behaviors and 12- month word comprehension, gestures and vocal production, controlling for cognitive performance and neonatal condition (ELGA vs FT).

METHODS

Forty infants, 20 ELGA and 20 FT, and their mothers participated in the study. Mother-infant play interaction was video-recorded at 6 and 12 months. Oral and manual object exploration at 6 months and spontaneous gestures and vocal production at 12 months were coded. Word comprehension was evaluated with the Italian version of the MacArthur-Bates CDI parent questionnaire at 12 months. Cognitive performance was examined with the Griffiths Mental Developmental Scales at 6 months and the Bayley-III Scales at 12 months.

RESULTS

Regression analyses showed that after accounting for cognitive performance and neonatal condition, oral exploration was related to word comprehension, and manual exploration to gestures and vocal production in the overall sample.

CONCLUSIONS

Cascading effects of specific object exploration skills on gestures and language comprehension and production in preterm infants and FT infants are discussed. Clinical implications for early assessment of and interventions involving object exploration skills, which may affect language development, are considered for the preterm population.

Neurodevelopmental Outcomes in Early Childhood

Technological advances in neonatal-perinatal medicine have led to a steady increase in the survival of preterm infants. Although the increase in survival is a remarkable success, children born preterm remain at high risk for brain injury and long-term neurodevelopmental deficits. Children born preterm may have abnormal muscle tone or movements, cognitive deficits, language impairments, and behavioral problems. This article reviews neurodevelopmental outcomes and factors that influence outcomes in preterm children during early childhood.

Neurodevelopmental Outcomes of Preterm Children at School Age and Beyond

Despite improved survival of preterm infants, there has not been an equivalent improvement in long-term neurodevelopmental outcomes. Adverse neurodevelopmental outcome rates and severity are inversely related to the degree of prematurity, but only 1.6% are born very preterm and the motor, cognitive, behavioral, and psychiatric disabilities in the large moderate and late preterm population have a greater impact. The disability-free preterm adult has a lower educational achievement and income but similar health-related quality of life to term controls. Reducing the long-term neurodevelopmental impact of prematurity is the next frontier of neonatal care.

Implementation of a pilot program of Reach Out and Read® in the neonatal intensive care unit: a quality improvement initiative

OBJECTIVE

Language exposure is important for neurodevelopment, but is sparse in the neonatal intensive care unit (NICU).

STUDY DESIGN

We introduced Reach Out and Read (ROR) in the NICU as a quality improvement initiative to increase language exposure. Measures included availability of books, accessibility of parents, and enrollment of infants, percent infants read to by their parents, and data from parental surveys.

RESULT

98 infants were included (40 before, 58 after). We obtained books in the mother's language for 95% of infants, 82% eligible infants were enrolled, and 70% read to their infants (mean of 0.45 ± 0.35 times/day). Surveyed parents enjoyed reading, noted positive effect(s), and intended to read post-discharge.

CONCLUSION

We launched a well-received pilot ROR program in the NICU and reached our goal of ≥50% infants being read to by their parents. Further study is needed to assess the impact of reading in the NICU on parents and infants.

Parent participation in the neonatal intensive care unit: Predictors and relationships to neurobehavior and developmental outcomes

OBJECTIVE

To 1) define predictors of parent presence, any holding, holding in arms, and skin-to-skin care in the NICU and 2) investigate the relationships between parent participation and a) early neurobehavior and b) developmental outcomes at age 4 to 5years among preterm infants.

METHODS

Eighty-one preterm infants born ≤32weeks estimated gestational age were prospectively enrolled within one week of life in a level III-IV NICU. Parent (maternal and paternal) presence and holding (including holding in arms and skin-to-skin care) were tracked throughout NICU hospitalization. Neurobehavior at term equivalent age and development at 4 to 5years were determined using standardized assessments.

RESULTS

The median number of days per week parents were documented to be present over NICU hospitalization was 4.0 (IQR=2.4-5.8) days; days held per week 2.8 (IQR=1.4-4.3) days [holding in arms days per week was 2.2 (IQR=1.2-3.2) days and parent skin-to-skin care days per week was 0.2 (IQR=0.0-0.7) days]. More parent presence was observed among mothers who were Caucasian, married, older, or employed and among those who had fewer children, familial support and provided breast milk (p<0.05). More holding was observed in infants with fewer medical interventions (p<0.05) and among those who were Caucasian, had a father who was employed, had fewer children and family support (p<0.05). More parent holding in the NICU was related to better reflex development at term age (p=0.02). More parent skin-to-skin care was related to better infant reflexes (p=0.03) and less asymmetry (p=0.04) at term and better gross motor development (p=0.02) at 4-5years.

DISCUSSION

Social and medical factors appear to impact parent presence, holding, and skin-to-skin care in the NICU. Parent holding is related to better developmental outcomes, which highlights the importance of engaging families in the NICU.

Do Infants Born Very Premature and Who Have Very Low Birth Weight Catch Up With Their Full Term Peers in Their Language Abilities by Early School Age?

PURPOSE

This study examined the extent to which children born preterm (< 37 weeks) and/or who have low birth weight (< 2,500 g) catch up with their full term peers in terms of their language abilities at early school age (≥ 5 to < 9 years).

METHOD

A systematic literature search identified empirical studies that fit the inclusion criteria. Data from the tests/questionnaires used for meta-analysis spanned the following language categories: total language score, expressive language, receptive language, pragmatics, phonological awareness, and grammar. The means (standard deviations) were extracted from the studies and were converted to mean difference and 95% confidence intervals to test for overall effect.

RESULTS

Sixteen studies met the inclusionary criteria, for a total of 2,739 participants, of which 1,224 were born full term and 1,515 were born preterm. It is important to note that the preterm cohort represented very preterm infants who have a very low birth weight. The meta-analysis found that preterm infants scored significantly worse on total language (p < .001), receptive language (p < .001), expressive language (p < .001), phonological awareness (p < .001), and grammar (p = .03) than their full term peers. However, preterm infants did not score significantly worse than their peers on their pragmatics (p = .19).

CONCLUSIONS

Children born VPT and who have VLBW perform worse than their peers on their total language, receptive language, expressive language, phonological awareness, and grammar abilities by early school age. This information is important for speech-language pathologists to consider as children born prematurely reach school age.

Immuno-modulator inter-alpha inhibitor proteins ameliorate complex auditory processing deficits in rats with neonatal hypoxic-ischemic brain injury

Hypoxic-ischemic (HI) brain injury is recognized as a significant problem in the perinatal period, contributing to life-long language-learning and other cognitive impairments. Central auditory processing deficits are common in infants with hypoxic-ischemic encephalopathy and have been shown to predict language learning deficits in other at risk infant populations. Inter-alpha inhibitor proteins (IAIPs) are a family of structurally related plasma proteins that modulate the systemic inflammatory response to infection and have been shown to attenuate cell death and improve learning outcomes after neonatal brain injury in rats. Here, we show that systemic administration of IAIPs during the early HI injury cascade ameliorates complex auditory discrimination deficits as compared to untreated HI injured subjects, despite reductions in brain weight. These findings have significant clinical implications for improving central auditory processing deficits linked to language learning in neonates with HI related brain injury.

Development skills of children born premature with low and very low birth weight

Purpose

To compare the performance of children born premature with low birth weight (LBW) and very low birth-weight (VLBW) with that of children born at term, within the age range of one to three years, regarding child development in the gross motor, fine motor-adaptive, personal-social and language domains.

Methods

This is a cross-sectional study in a cohort of 150 infants born premature (experimental group) and at term (control group) divided into eight groups with respect to weight (low birth weight: <2500 grams and very low birth weight: <1500 grams) and age range (aged 12 to 24 and 25 to 36 months). The control groups were paired with the experimental groups as for gender, chronological age, and socioeconomic level. Assessment comprised the application of anamnesis protocol, socioeconomic classification, and Denver Developmental Screening Test (DDST-II). Corrected age was calculated for premature children up to 24 months of age. Descriptive statistical analysis and the Student's t-test were used.

Results

No statistically significant difference was found in the comparison between the groups of infants born premature and at term for all domains evaluated.

Conclusion

The performance of infants born premature was lower than that of infants born at term regarding the gross motor, fine motor-adaptive, personal-social and language domains. In this study, the preterm groups presented different performances, i.e., normative, average, and below average performances were observed within the same group.

Language and hearing outcomes of preterm infants

Multiple factors including degree of prematurity, neonatal morbidities, illness severity, hearing status, gender, language environment in the neonatal intensive care unit and in the home, maternal education level, social and environmental status of the family, and access to early intervention all contribute to the language outcomes of extremely preterm infants with and without hearing loss. Early screening, early diagnosis, and early intervention services by 6 months of age are necessary to optimize the language outcomes of preterm infants with permanent hearing loss. There is increasing evidence of the potential for improved language skills with increasing age of extreme preterm infants and infants with hearing loss.

The effect of pre-eclampsia-like syndrome induced by L-NAME on learning and memory and hippocampal glucocorticoid receptor expression: A rat model

OBJECTIVE

We aimed to study the impacts of pre-eclampsia on the cognitive and learning capabilities of adolescent rat offspring and to explore the possible underlying mechanisms at the molecular level.

METHODS

Pregnant rats were subcutaneously injected with saline solution (control) (n = 16) or NG-nitro-L-arginine methyl ester (L-NAME) (n = 16) from the 13th day of gestation until parturition. The brain tissues from fetal rats delivered by cesarean section were examined in both groups with hematoxylin and eosin (H&E) staining. Rats born vaginally in both groups were subjected to the Morris water maze test when 8-week-old and their hippocampi were analyzed for glucocorticoid receptor (GR) expression.

RESULTS

A pre-eclampsia-like model was successfully built in pregnant rats by infusion of the NO synthase inhibitor L-NAME, including phenotypes as maternal hypertension and proteinuria, high stillbirth rate, and fetal growth retardation. Neuroepithelial cell proliferation was found in the hippocampus of fetal rats in the L-NAME group. Grown to 8-week-old, the L-NAME group showed significantly longer escape latency than the control group in the beginning as well as in the end of navigation trials. At the same time, the swimming distance achieved by the L-NAME group was significantly longer than that of the control group. Such differences in cognitive and learning capabilities between the two groups were not gender dependent. Besides, the 8-week-old rats in the L-NAME group had increased GR expression in the hippocampus than the control group.

CONCLUSION

Pre-eclampsia would impair cognitive and learning capabilities in adolescent offspring, and the upregulated expression of hippocampal GR may be involved in the underlying mechanisms.

The Effect of Age and History of Recurrent Otitis Media on Dichotic Listening and Verbal Memory in Children

OBJECTIVES

To explore the possible effects of recurrent otitis media (ROM) in early childhood on binaural processing and verbal memory in school-aged children.

METHODS

Two hundred eleven children, including 31 children with and 180 children without a history of ROM, were examined. A dichotic digit test (DDT) and a forward and backward digit memory span test (DMST) were administered.

RESULTS

A significant difference was observed between age groups among ROM-free children. The ROM-positive group earned significantly poorer results than the ROM-free group in all measurements, except for the right DDT (rDDT) score. Furthermore, a significant correlation was found between the DDT and EA scores with both DMST scores in the ROM-free group. The correlation between the rDDT and forward DMST scores was not significant in the ROM-positive group, and no significant correlation was observed between the EA score and either DMST score.

CONCLUSIONS

Our findings support that a history of OM in early childhood based on a parental survey of children is associated with differences in DDT and DMST outcomes.

Receptive language and intellectual abilities in preterm children

OBJECTIVE

The aim of this study was to examine the association between receptive vocabulary performance and intellectual quotient (IQ) in preterm born children compared to children born at term.

METHOD

A total of 72 preschool-age children participated in the study. Participants were divided in four groups: EG-I, including 20 moderate to late preterm born children; EG-II, comprehending 16 extremely preterm born children; CG-I and CG-II with correspondingly 20 and 16 children born at term. EG-I and CG-I as well as EG-II and CG-II groups were matched according to gender, chronological age, and family SES. The mean age of children in each group was: EG-I and CG-I: 30.3months; EG-II and CG-II: 29.1months. The assessment information was collected using an anamnesis protocol, the Brazilian criterion of economic classification, the Peabody Picture Vocabulary Test, and the Stanford-Binet Intelligence Scale.

RESULTS

Mean scores for receptive vocabulary were significantly lower in both preterm groups (EG-I and EG-II) than in the corresponding matched groups (CG-I and CG-II). However, no significant differences were found among the preterm groups. Moreover, high correlations between vocabulary and IQ scores were found in both preterm groups (EG-I and EG-II). In contrast, no significant correlations were found when analyses considered each group of full-term born children (CG-I and CG-II).

CONCLUSION

Our findings indicate that prematurity status has an impact on receptive language performance and on the pattern of relationships between receptive vocabulary and general intellectual functioning.

Do the early development of gestures and receptive and expressive language predict language skills at 5;0 in prematurely born very-low-birth-weight children?

It is unclear what the predictive value of very early development of gestures and language is on later language ability in prematurely born very-low-birth-weight (VLBW; birth weight ≤1500g) children. The aim of the present study was to analyse the predictive value of early gestures and a receptive lexicon measured between the ages of 0;9 and 1;3, as well as the predictive value of receptive and expressive language ability at 2;0 for language skills at 5;0 in VLBW children. The subjects were 29 VLBW children and 28 full-term children whose language development has been followed intensively between the ages of 0;9 and 2;0 using the Finnish version of the MacArthur Developmental Inventory and the Reynell Developmental Language Scales (RDLS III). At 5;0, five selected verbal subtests of the Nepsy II test and the Boston Naming Test (BNT) were used to assess children's language skills. For the first time in VLBW children, the development of gestures measured between the ages of 0;9 and 1;3 was shown to correlate significantly and positively with language skills at 5;0. In addition, both receptive and expressive language ability measured at 2;0 correlated significantly and positively with later language skills in both groups. Moreover, according to the hierarchical regression analysis, the receptive language score of the RDLS III at 2;0 was a clear and significant predictor for language skills at 5;0 in both groups. The findings particularly underline the role of early receptive language as a significant predictor for later language ability in VLBW children. The results provide evidence for a continuity between early language development and later language skills.

LEARNING OUTCOMES

After reading this article, readers will understand the associations between the very early (≤2 years of age) development of gestures and language (i.e. early receptive lexicon, expressive lexicon at 2;0, receptive and expressive language ability at 2;0) and the language skills at 5;0 in prematurely born very-low-birth-weight (VLBW) children. In addition, readers will understand the heterogeneity of the group of VLBW children. The information presented in this article is informative for those who work in a clinical context and who want to be able to identify those VLBW children who need support for their language development at an early age.

Early communicative behaviors and their relationship to motor skills in extremely preterm infants

Despite the predictive value of early spontaneous communication for identifying risk for later language concerns, very little research has focused on these behaviors in extremely low-gestational-age infants (ELGA<28 weeks) or on their relationship with motor development. In this study, communicative behaviors (gestures, vocal utterances and their coordination) were evaluated during mother-infant play interactions in 20 ELGA infants and 20 full-term infants (FT) at 12 months (corrected age for ELGA infants). Relationships between gestures and motor skills, evaluated using the Bayley-III Scales were also examined. ELGA infants, compared with FT infants, showed less advanced communicative, motor, and cognitive skills. Giving and representational gestures were produced at a lower rate by ELGA infants. In addition, pointing gestures and words were produced by a lower percentage of ELGA infants. Significant positive correlations between gestures (pointing and representational gestures) and fine motor skills were found in the ELGA group. We discuss the relevance of examining spontaneous communicative behaviors and motor skills as potential indices of early development that may be useful for clinical assessment and intervention with ELGA infants.

Does temperament influence language development? Evidence from preterm and full-term children

The aims of this study are: (1) to describe language and temperament characteristics of one group of low risk preterm (PR) children and a group of full-term (FT) children and (2) to identify those factors which can predict language outcomes at 30 months of age, with special attention on temperament. There is evidence of differences between very or extremely PR and FT children in relation to characteristics of temperament and language development. However, not many studies have been carried out with healthy PR children. The participants were 142 low risk PR children (mean gestational age (GA): 32.60 weeks) and 49 FT children (mean GA 39.84 weeks). The temperament of the children was assessed at 10 months of age through the Infant Behavior Questionnaire-Revised (IBQ-R). At 22 months of age the cognitive development of the children was assessed through the Spanish adaptation of the Batelle Developmental Inventory (BDI). In order to assess the children's language development the Galician adaptation of the MacArthur-Bates CDI was applied at 30 months of age. In addition, socio-demographic information about the children and their families was gathered at birth. The results indicate that there were no significant differences in the language measures of interest (word production, MLU3, and sentence complexity) between groups. The only differences found between the PR and the FT children in the IBQ-R were restricted to the smiling and laughter and the fear subscales. Hierarchical regression analyses performed indicate that GA did not have any predictive effect on language measures taken at 30 months. Cognitive scores were an important predictor of language measures, although certain temperament subscales contributed in a significant way to the variance of language measures, particularly low intensity pleasure, approach, high intensity pleasure, sadness, and vocal reactivity. Therefore, extroverted (positive affectivity) temperament seems to be beneficial for language development.

Noun and predicate comprehension/production and gestures in extremely preterm children at two years of age: Are they delayed?

Extremely low gestational age (ELGA, GA<28 weeks) preterm children are at high risk for linguistic impairments; however, their lexical comprehension and production as well as lexical categories in their early language acquisition have not been specifically examined via direct tools. Our study examines lexical comprehension and production as well as gestural production in ELGA children by focusing on noun and predicate acquisition. Forty monolingual ELGA children (mean GA of 26.7 weeks) and 40 full-term (FT) children were assessed at two years of corrected chronological age (CCA) using a test of noun and predicate comprehension and production (PiNG) and the Italian MB-CDI. Noun comprehension and production were delayed in ELGA compared with FT children, as documented by the low number of correct responses and the large number of errors, i.e., incorrect responses and no-response items, and by the types of incorrect responses, i.e., fewer semantically related responses, in noun production. Regarding predicate comprehension and production, a higher frequency of no responses was reported by ELGA children and these children also presented a lower frequency of bimodal spoken-gestural responses in predicate production than FT children. A delayed vocabulary size as demonstrated by the MB-CDI, was exhibited by one-fourth of the ELGA children, who were also unable to complete the predicate subtest. These findings highlight that noun comprehension and production are delayed in ELGA children at two years of CCA and are the most important indexes for the direct evaluation of their lexical abilities and delay. The types of incorrect responses and bimodal spoken-gestural responses were proven to be useful indexes for evaluating the noun and predicate level of acquisition and to plan early focused interventions.

LEARNING OUTCOMES

After reading this manuscript, the reader will understand (a) the differences in noun and predicate comprehension and production between ELGA and FT children and the indexes of lexical delays exhibited by ELGA children at 2;0 (CCA); (b) the relevance of evaluating errors (incorrect response and no response), the types of incorrect responses (semantically related and unrelated) and the modality of the responses (unimodal spoken and bimodal spoken-gestural) in noun and predicate production to understand the difficulties experienced by ELGA children in representing and expressing meanings; and (c) the need to plan specific interventions to support spoken and gestural modalities in lexical comprehension and production in ELGA children by focusing on noun and predicate acquisition.

[Language acquisition in preterm infants during the first year of life]

Previous studies have shown that preterm children are at a higher risk for cognitive and language delays than full-term children. Most of these studies have concentrated on the effects of prematurity during the preschool or school years, while the effect of preterm birth on the early development of language, much of which occurs during the first year of life, remains very little explored. This article focuses on this crucial period and reviews the studies that have explored early phonological and lexical development in preterm infants. The results of these studies show uneven proficiency in different language subdomains in preterm infants. This raises the possibility that different constraints apply to the acquisition of different linguistic subcomponents in this population, in part as a result of a complex interaction between maturation, experience, and language subdomains.

Language outcomes among ELBW infants in early childhood

BACKGROUND

Limited data are available evaluating language outcomes of preterm infants in early childhood. Furthermore, the relationship between language outcomes, medical morbidities and developmental trajectory in early infancy is unclear.

AIMS

The goal of this study was to evaluate language outcomes among extremely low birth weight (ELBW) infants at 30months adjusted age (AA).

STUDY DESIGN

The Bayley Scales of Infant Development II and the Peabody Picture Vocabulary Test or Expressive One Word Picture Vocabulary Test/Receptive One Word Picture Vocabulary Test were administered at 30months AA to a prospective cohort of ELBW infants who participated in the NICHD Neonatal Network Glutamine Trial and Neurodevelopmental Follow-Up Study. A standardized history and physical examination and query regarding feeding behaviors were performed at 18months AA and 30months AA.

RESULTS

Of the 467 infants evaluated, 55% had receptive language delay at 30months with 23% having severe delays. Fewer (26%) had expressive language delays, with 16% of those being severe delays. Non-English speaking infants had poorer performance on all language measures compared to English-speaking infants. Forty-seven percent of the cohort required assistance with feeds at 18months. These children were more likely to have language delay at the 30month assessment compared to infants who could feed themselves.

CONCLUSIONS

ELBW infants are at risk of language delay in early childhood. Additional research is needed to further explore the relationship between early predictors of language delay and the use of monolingual language assessments in non-English speaking patients with a history of prematurity.

Sex differences in behavioral outcomes following temperature modulation during induced neonatal hypoxic ischemic injury in rats

Neonatal hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain) can cause various degrees of tissue damage, as well as subsequent cognitive/behavioral deficits such as motor, learning/memory, and auditory impairments. These outcomes frequently result from cardiovascular and/or respiratory events observed in premature infants. Data suggests that there is a sex difference in HI outcome, with males being more adversely affected relative to comparably injured females. Brain/body temperature may play a role in modulating the severity of an HI insult, with hypothermia during an insult yielding more favorable anatomical and behavioral outcomes. The current study utilized a postnatal day (P) 7 rodent model of HI injury to assess the effect of temperature modulation during injury in each sex. We hypothesized that female P7 rats would benefit more from lowered body temperatures as compared to male P7 rats. We assessed all subjects on rota-rod, auditory discrimination, and spatial/non-spatial maze tasks. Our results revealed a significant benefit of temperature reduction in HI females as measured by most of the employed behavioral tasks. However, HI males benefitted from temperature reduction as measured on auditory and non-spatial tasks. Our data suggest that temperature reduction protects both sexes from the deleterious effects of HI injury, but task and sex specific patterns of relative efficacy are seen.

Dissociation in the Effects of Induced Neonatal Hypoxia-Ischemia on Rapid Auditory Processing and Spatial Working Memory in Male Rats

Infants born prematurely are at risk for cardiovascular events causing hypoxia-ischemia (HI; reduced blood and oxygen to the brain). HI in turn can cause neuropathology, though patterns of damage are sometimes diffuse and often highly variable (with clinical heterogeneity further magnified by rapid development). As a result, though HI injury is associated with long-term behavioral and cognitive impairments in general, pathology indices for specific infants can provide only limited insight into individual prognosis. The current paper addresses this important clinical issue using a rat model that simulates unilateral HI in a late preterm infant coupled with long-term behavioral evaluation in two processing domains - auditory discrimination and spatial learning/memory. We examined the following: (1) whether deficits on one task would predict deficits on the other (suggesting that subjects with more severe injury perform worse across all cognitive domains) or (2) whether domain-specific outcomes among HI-injured subjects would be uncorrelated (suggesting differential damage to orthogonal neural systems). All animals (sham and HI) received initial auditory testing and were assigned to additional auditory testing (group A) or spatial maze testing (group B). This allowed within-task (group A) and between-task (group B) correlation. Anatomic measures of cortical, hippocampal and ventricular volume (indexing HI damage) were also obtained and correlated against behavioral measures. Results showed that auditory discrimination in the juvenile period was not correlated with spatial working memory in adulthood (group B) in either sham or HI rats. Conversely, early auditory processing performance for group A HI animals significantly predicted auditory deficits in adulthood (p = 0.05; no correlation in shams). Anatomic data also revealed significant relationships between the volumes of different brain areas within both HI and shams, but anatomic measures did not correlate with any behavioral measure in the HI group (though we saw a hippocampal/spatial correlation in shams, in the expected direction). Overall, current data provide an impetus to enhance tools for characterizing individual HI-related pathology in neonates, which could provide more accurate individual prognoses within specific cognitive/behavioral domains and thus improved patient-specific early interventions.

A 22-element micronutrient powder benefits language but not cognition in Bangladeshi full-term low-birth-weight children

BACKGROUND

Low-birth-weight children are known to be at risk of both anemia and cognitive/language deficits in their early years.

OBJECTIVE

The aim of the current study was to examine the effects of a 22-element multiple micronutrient powder (MNP) on the cognitive and language development of full-term low-birth-weight (LBW-T) children in Bangladesh.

METHODS

The current study was a follow-up of children who were enrolled in a randomized cluster trial at 7-12 mo of age. Children in 12 intervention clusters (communities) were administered a daily 22-element MNP sachet with their food for 5 mo, and both intervention and control groups (also 12 clusters) received nutrition, health, and hygiene education. The current study involved the assessment of children at 16-22 mo of age (22-element MNP group: n = 96; control group: n = 82) on 3 subtests of the Bayley Scales of Infant and Toddler Development III test to measure cognitive, receptive language, and expressive language development.

RESULTS

There was a significant effect of the 22-element MNP on children's expressive language scores (d = 0.39), and stunting moderated the effect on receptive language scores; there was no effect on cognitive development (d = 0.08).

CONCLUSION

An MNP may thus offer one feasible solution to improve language development of LBW-T children in low-resource community settings. This trial was registered at clinicaltrials.gov as NCT01455636.

Early visual attention in preterm and fullterm infants in relation to cognitive and motor outcomes at school age: an exploratory study

OBJECTIVE

Preterm infants are exposed to the visual environment earlier than fullterm infants, but whether early exposure affects later development is unclear. Our aim was to investigate whether the development of visual disengagement capacity during the first 6 months postterm was associated with cognitive and motor outcomes at school age, and whether associations differed between fullterms and low-risk preterms.

METHOD

Seventeen fullterms and ten low-risk preterms were tested in a gaze shifting task every 4 weeks until 6 months postterm. The longitudinal data were converted into single continuous variables by fitting the data with an S-shaped curve (frequencies of looks) or an inverse model (latencies of looks). Neuropsychological test results at school age were converted into composite z scores. We then performed linear regression analyses for each functional domain at school age with the variables measuring infant visual attention as separate predictors and adjusting for maternal level of education and group (fullterms versus preterms). We included an interaction term, visual attention*group, to determine whether predictive relations differed between fullterms and preterms.

RESULTS

A slower development of disengagement predicted poorer performance on attention, motor skills, and handwriting, irrespective of fullterm or preterm birth. Predictive relationships differed marginally between fullterms and preterms for inhibitory attentional control (P = 0.054) and comprehensive reading (P = 0.064).

CONCLUSION

This exploratory study yielded no indications of a clear advantage or disadvantage of the extra visual exposure in healthy preterm infants. We tentatively conclude that additional visual exposure does not interfere with the ongoing development of neuronal networks during this vulnerable period of brain development.

Habituation responses to external stimuli: is the habituation of preterm infants at a postconceptual age of 40 weeks equal to that of term infants?

OBJECTIVE

Compare the habituation responses to external stimuli between preterm infants at the postconceptual age of 40 weeks and term infants in the first days of life, and evaluate the habituation responses of the preterm infants until the age of 40 postconceptual weeks.

METHODS

Prospective cohort study of preterm infants aged <32 weeks. The habituation responses to light, rattle, bell and tactile stimuli of preterm infants were assessed at 32, 34, 36 and 38-40 postconceptual weeks. External stimuli were presented and responses were scored according to Lester and Tronik (2004). Habituation scores were compared between preterm and term infants, matched by sex, using t test. Repeated measures ANOVA was used to compare the responses between the different postconceptual gestational ages. Contrast models were used to verify the differences between the habituation responses according to the type of stimulus and the postconceptual ages.

RESULTS

51 preterm infants were studied (gestational age 29.4±2.4w; birth weight 1230±323 g). The scores for the habituation responses to the four stimuli progressively increased with advancing postconceptual age. At the age of 40 postconceptual weeks, the preterm infants were habituated to external stimuli similarly to the 51 studied term infants. The preterm infants showed higher habituation response scores for the rattle and bell stimuli than for the light and tactile stimuli.

CONCLUSIONS

Preterm infants improve their habituation responses to external stimuli as their postconceptual age increases, and, at 40 weeks of corrected age, they have similar responses to those exhibited by full-term infants in the first days of life.

Effects of inter-alpha inhibitor proteins on neonatal brain injury: Age, task and treatment dependent neurobehavioral outcomes

Hypoxic-ischemic (HI) brain injury is frequently associated with premature and/or full term birth related complications. HI injury often results in learning and processing deficits that reflect widespread damage to an extensive range of cortical and sub-cortical brain structures. Further, inflammation has been implicated in the long-term progression and severity of HI injury. Recently, inter-alpha inhibitor proteins (IAIPs) have been shown to attenuate inflammation in models of systemic infection. Importantly, preclinical studies of neonatal HI injury and neuroprotection often focus on single time windows of assessment or single behavioral domains. This approach limits translational validity, given evidence for a diverse spectrum of neurobehavioral deficits that may change across developmental windows following neonatal brain injury. Therefore, the aims of this research were to assess the effects of human IAIPs on early neocortical cell death (72h post-insult), adult regional brain volume measurements (cerebral cortex, hippocampus, striatum, corpus callosum) and long-term behavioral outcomes in juvenile (P38-50) and adult (P80+) periods across two independent learning domains (spatial and non-spatial learning), after postnatal day 7 HI injury in rats. Here, for the first time, we show that IAIPs reduce acute neocortical neuronal cell death and improve brain weight outcome 72h following HI injury in the neonatal rat. Further, these longitudinal studies are the first to show age, task and treatment dependent improvements in behavioral outcome for both spatial and non-spatial learning following systemic administration of IAIPs in neonatal HI injured rats. Finally, results also show sparing of brain regions critical for spatial and non-spatial learning in adult animals treated with IAIPs at the time of injury onset. These data support the proposal that inter-alpha inhibitor proteins may serve as novel therapeutics for brain injury associated with premature birth and/or neonatal brain injury and highlight the importance of assessing multiple ages, brain regions and behavioral domains when investigating experimental treatment efficacy.

The hemodynamic response to acoustically modified syllables in premature and full term newborn infants acquired by near infrared spectroscopy

This research assesses, in newborns, the hemodynamic response to acoustically modified syllables (pronounced in a prolonged manner), versus the response to unmodified syllables (pronounced at a normal rate). The aim was to assess which of these stimulation conditions produced better syllable discrimination in two groups of neonates: 13 preterm (mean gestational age 30 weeks, SD 3 weeks), and 13 full term newborns (mean age 38 weeks, SD 1 week). Syllable discrimination, in each condition, was assessed by using an oddball paradigm (equal syllable trials vs. different syllable trials). The statistical analysis was based on the comparison between the hemodynamic response [oxyHbO] obtained by Near Infrared Spectroscopy (NIRS) to different syllable trials vs. equal syllable trials, in each condition. The modified syllable condition was better in producing trial discrimination in both groups. The amplitude of the hemodynamic response to the different syllable trials was greater than the one to the equal syllable trials: for term infants, t = 2.59, p = 0.024, and for preterm t = 2.38, p = 0.035. This finding occurred in the left temporal lobe. These data suggest that the modified syllables facilitate processing of phonemes from birth.

Language, motor and cognitive development of extremely preterm children: modeling individual growth trajectories over the first three years of life

Survival rate of extremely low gestational age (ELGA) newborns has increased over 80% in the last 15 years, but its consequences on the short- and longer-term developmental competencies may be severe. The aim of this study was to describe growth trajectories of linguistic, motor and cognitive skills among ELGA children, compared to full-term (FT) peers, from the first to the third year of life, a crucial period for development. Growth curve analysis was used to examine individual and group differences in terms of initial status at 12 months and rate of growth through the second and the third year of life with five points of assessment. Twenty-eight monolingual Italian children, of whom 17 were ELGA (mean GA 25.7 weeks) and 11 were FT children, were assessed through the BSID-III at 12, 18, 24, 30 and 36 months for language skills and at 12, 24 and 30 months for motor and cognitive skills. ELGA children presented significantly lower scores than FT peers in language, motor and cognitive skills and they did not overcome their disadvantage by 3 years, even if their corrected age was taken into account. Concerning growth curves, in motor development a significant increasing divergence was found showing a Matthew effect with the preterm sample falling further behind the FT sample. In linguistic and cognitive development, instead, a stable gap between the two samples was found. In addition, great inter-individual differences in rate of change were observed for language development in both samples. Our findings highlight the theoretical and clinical relevance of analyzing, through growth curve analyses, the developmental trajectories of ELGA children in language skills taking into account their inter-individual variability also across motor and cognitive domains.

LEARNING OUTCOMES

After reading this article, the reader will interpret: (a) characteristics and growth trajectories of ELGA children from the first to the third year of life with respect to FT children in language, motor and cognitive development; (b) the method of growth curve analyses to describe group as well as inter-individual trajectories; (c) the rate of inter-individual variability in language as well as motor and cognitive skills, which gives useful indications for early interventions.

The development and predictive value of gestures in very-low-birth-weight children: a longitudinal study

The present study analysed the development of gestures between 0;9-1;3 years, and the predictive value of this development for language skills at 2;0 in very-low-birth-weight (VLBW) children. Participants were 32 VLBW children and their 35 controls. The data on gestures was gathered using the Finnish version of the Communicative Development Inventory (FinCDI). At 2;0, the language skills of the children were assessed using the Reynell Developmental Language Scales (RDLS III) and the FinCDI. The number of acquired gestures was lower in the VLBW children than in the controls. The development of gestures correlated significantly with later expressive language in both groups, but significant correlations between the development of gestures and later receptive language development were detected only in the VLBW group. When the predictive value of gestures and early expressive and receptive lexicon with regard to later language skills were analysed, the development of gestures at 1;3 had good predictive value for poor language performance at 2;0. In addition, a small receptive lexicon size at 1;0 and at 1;3 was also a good predictor for later language performance. The development of gestures and receptive lexicon thus jointly provide clinically valuable information on the emerging language skills of VLBW children.

Cell size anomalies in the auditory thalamus of rats with hypoxic-ischemic injury on postnatal day 3 or 7

Children born prematurely (<37 weeks gestational age) or at very low birth weight (VLBW; <1500g) are at increased risk for hypoxic ischemic (HI) brain injuries. Term infants can also suffer HI from birth complications. In both groups, blood/oxygen delivery to the brain is compromised, often resulting in brain damage and later cognitive delays (e.g., language deficits). Literature suggests that language delays in a variety of developmentally impaired populations (including specific language impairment (SLI), dyslexia, and early HI-injury) may be associated with underlying deficits in rapid auditory processing (RAP; the ability to process and discriminate brief acoustic cues). Data supporting a relationship between RAP deficits and poor language outcomes is consistent with the "magnocellular theory," which purports that damage to or loss of large (magnocellular) cells in thalamic nuclei could underlie disruptions in temporal processing of sensory input, possibly including auditory (medial geniculate nucleus; MGN) information This theory could be applied to neonatal HI populations that show subsequent RAP deficits. In animal models of neonatal HI, persistent RAP deficits are seen in postnatal (P)7 HI injured rats (who exhibit neuropathology comparable to term birth injury), but not in P1-3 HI injured rodents (who exhibit neuropathology comparable to human pre-term injury). The current study sought to investigate the mean cell size, cell number, and cumulative probability of cell size in the MGN of P3 HI and P7 HI injured male rats that had previously demonstrated behavioral RAP deficits. Pilot data from our lab (Alexander, 2011) previously revealed cell size abnormalities (a shift toward smaller cells) in P7 but not P1 HI injured animals when compared to shams. Our current finding support this result, with evidence of a significant shift to smaller cells in the experimental MGN of P7 HI but not P3 HI subjects. P7 HI animals also showed significantly fewer cells in the affected (right) MGN as compared P3 HI and shams animals. Moreover, cell number in the right hemisphere was found to correlate with gap detection (fewer cells=worse performance) in P7 HI injured subjects. These findings could be applied to clinical populations, providing an anatomic marker that may index potential long-term language disabilities in HI injured infants and possibly other at-risk populations.

Speech and language outcomes of very preterm infants

Speech and language impairments of both simple and complex language functions are common among former preterm infants. Risk factors include lower gestational age and increasing illness severity including severe brain injury. Even in the absence of brain injury, however, altered brain maturation and vulnerability imposed by premature entrance to the extrauterine environment is associated with brain structural and microstructural changes. These alterations are associated with language impairments with lasting effects in childhood and adolescence and increased needs for speech therapy and education supports. Studies are needed to investigate language interventions which begin in the neonatal intensive care unit.

Basic numerical processes in very preterm children: a critical transition from preschool to school age

BACKGROUND

Serious difficulties in formal mathematical skills have been identified in preterm children. By contrast, basic-level numerical skills like magnitude judgments have not yet been tested in these children.

AIMS

The aim of the present research was to investigate whether preterm birth also affects these basic numerical abilities, with particular attention to the transition from preschool to formal education.

METHOD

One hundred-forty very preterm children and 60 age-matched controls were recruited in a cross-sectional study at 6 and 8years of age. Magnitude comparison tasks with non-symbolic dot displays or symbolic Arabic-number stimuli, measuring accuracy and reaction time, were administered to participants. We also investigated explicit number knowledge, as well as general cognitive developmental levels, to gain a broader picture of preterm abilities.

RESULTS

Despite no general cognitive delay, the more simple approximate non-symbolic representation of numerical magnitude was affected by preterm birth, with slower reaction times at both ages compared to controls. Additionally, clear difficulties in the construction of the symbolic representation of numerical magnitude and in explicit number knowledge emerged in the 6-year-old preterm children, with a recovery from this serious delay finally by 8years.

CONCLUSIONS

The serious delays identified here in basic numerical abilities in preterm children, despite normal IQ, point to the need for further studies in order to elucidate the relationship between basic numerical abilities and subsequent difficulties in formal mathematic achievement at school.