Achievement in children with birth weights less than 750 grams with normal cognitive abilities: evidence for specific learning disabilities

Academic Outcomes of School-Aged Children Born Preterm: A Systematic Review and Meta-analysis

IMPORTANCE

Children born preterm are at an elevated risk of academic underachievement. However, the extent to which performance across domain-specific subskills in reading and mathematics is associated with preterm birth remains unclear.

OBJECTIVE

To conduct a systematic review and meta-analysis of academic outcomes of school-aged children born preterm, compared with children born at term, appraising evidence for higher- and lower-order subskills in reading and mathematics.

DATA SOURCES

PubMed/MEDLINE, PsycINFO, and the Cumulative Index of Nursing and Allied Health Literature electronic databases from January 1, 1980, to July 30, 2018, were searched for population, exposure, and outcome terms such as child (population), preterm birth (exposure), and education* (outcome).

STUDY SELECTION

Peer-reviewed English-language publications that included preterm-born children and a comparison group of term-born children aged 5 to 18 years and born during or after 1980 and that reported outcomes on standardized assessments from cohort or cross-sectional studies were screened. Of the 9833 articles screened, 33 unique studies met the inclusion criteria.

DATA EXTRACTION AND SYNTHESIS

Data were analyzed from August 1 to September 29, 2018. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Two reviewers independently screened the databases and extracted sample characteristics and outcomes scores. Pooled mean differences (MDs) were analyzed using random-effects models.

MAIN OUTCOMES AND MEASURES

Performance on standardized assessment of higher-order subskills of reading comprehension and applied mathematics problems; lower-order reading subskills of decoding, pseudoword decoding, and word identification; and lower-order mathematics subskills of knowledge, calculation, and fluency.

RESULTS

Outcomes data were extracted for 4006 preterm and 3317 term-born children, totaling 7323 participants from 33 unique studies. Relative to children born at term, children born preterm scored significantly lower in reading comprehension (mean difference [MD], -7.96; 95% CI, -12.15 to -3.76; I2 = 81%) and applied mathematical problems (MD, -11.41; 95% CI, -17.57 to -5.26; I2 = 91%) assessments. Across the assessments of lower-order skills, children born preterm scored significantly lower than their term-born peers in calculation (MD, -10.57; 95% CI, -15.62 to -5.52; I2 = 92%), decoding (MD, -10.18; 95% CI, -16.83 to -3.53; I2 = 71%), mathematical knowledge (MD, -9.88; 95% CI, -11.68 to -8.08; I2 = 62%), word identification (MD, -7.44; 95% CI, -9.08 to -5.80; I2 = 69%), and mathematical fluency (MD, -6.89; 95% CI, -13.54 to -0.23; I2 = 72%). The associations remained unchanged after sensitivity analyses for reducing heterogeneity.

CONCLUSIONS AND RELEVANCE

These findings provide evidence that preterm birth is associated with academic underperformance in aggregate measures of reading and mathematics, as well as a variety of related subskills.

Impact of major neonatal morbidities on adolescents born at 23-25 weeks of gestation

AIM

More infants born extremely preterm (EPT) are surviving, but major neonatal morbidities are consistently high. This study examined the impact of bronchopulmonary dysplasia (BPD), brain injuries and severe retinopathy of prematurity (ROP) on adolescents who were born EPT.

METHODS

We focused on EPT infants born at 23-25 weeks at the Swedish university hospitals in Uppsala and Umeå from January 1992 to December 1998. The poor outcome data covered 140 of 142 who survived to 36 weeks, and the chronic conditions data reported by parents covered 132 of 134 still alive at 10-15 years.

RESULTS

Of the 140 survivors at 36 weeks, 29 (21%) had poor outcomes: eight of 140 (6%) died, and 21 of 132 (16%) adolescent survivors had severe neurodevelopmental disabilities (NDD). BPD, severe ROP and/or brain injuries correlated independently with poor outcome. Of those adolescents who were free from BPD, brain injury and severe ROP, 6% had a severe NDD. The corresponding rates with any one, any two or all three neonatal morbidities were 21, 33 and 67%, respectively. BPD and brain injuries were associated with high rates of chronic conditions at 10-15 years of age resulting in functional limitations.

CONCLUSION

In adolescent EPT survivors, BPD and brain injuries were associated with high rates of chronic conditions and special healthcare needs.

Antenatal and neonatal antecedents of learning limitations in 10-year old children born extremely preterm

BACKGROUND

Children born extremely preterm are at increased risk of learning limitations.

AIM

To identify the antecedents of learning limitations of children born extremely preterm.

STUDY DESIGN

Prospective observational study from birth to age 10 years. Variables entered into the multinomial logistic regression analyses were ordered temporally, with the earliest occurring predictors/covariates of each learning limitation risk entered first and not displaced by later occurring covariates.

SUBJECTS

874 children who were born before the 28th week of gestation.

OUTCOME MEASURES

A reading limitation was defined as a score one or more standard deviations below the expected mean on the WIAT-III Word Reading and a mathematics limitation was defined as a similarly low score on the Numerical Operations component.

RESULTS

56 children had a "reading ONLY" limitation, 132 children had a "math ONLY" limitation and 89 children had "reading AND math" limitations. All risk profiles included an indicator of socioeconomic disadvantage (e.g., mother's "racial" identity and eligibility for government-provided health care insurance), an indicator of newborn's immaturity/vulnerability (e.g., high illness severity score, receipt of hydrocortisone, and/or ventilator-dependence at 36 weeks post-menstruation), and all but the math only limitation included an indicator of fetal growth restriction and inflammation (i.e., pregnancy urinary tract infection or late ventilator-dependence).

CONCLUSIONS

The themes of socioeconomic disadvantage and immaturity/vulnerability characterize all three risk profiles, while the themes of fetal growth restriction and inflammation are characteristic of a reading limitation only, and the reading and math limitations entity.

Learning disabilities among extremely preterm children without neurosensory impairment: Comorbidity, neuropsychological profiles and scholastic outcomes

BACKGROUND

Children born extremely preterm are at high risk for intellectual disability, learning disabilities, executive dysfunction and special educational needs, but little is understood about the comorbidity of intellectual and learning disabilities in this population.

AIMS

This study explored comorbidity in intellectual disability (ID) and learning disabilities (LD) in children born extremely preterm (EP; <26⁺⁰weeks' gestation).

SUBJECTS AND STUDY DESIGN

A UK national cohort of 161 EP children and 153 term-born controls without neurosensory impairments was assessed at 11years of age (the EPICure Study).

OUTCOME MEASURES

IQ, mathematics and reading attainment, executive function, visuospatial processing and sensorimotor skills were assessed using standardised tests, and curriculum-based attainment and special educational needs (SEN) using teacher reports.

RESULTS

Overall, 75 (47%) EP children and 7 (4.6%) controls had ID or LD (RR 10.12; 95% CI 4.81, 21.27). Comorbidity in ID/LD was more common among EP children than controls (24% vs. 0%). EP children with comorbid ID/LD had significantly poorer neuropsychological abilities and curriculum-based attainment than EP children with an isolated disability or no disabilities. LD were associated with a 3 times increased risk for SEN. However, EP children with ID alone had poorer neuropsychological abilities and curriculum-based attainment than children with no disabilities, yet there was no increase in SEN provision among this group.

CONCLUSIONS

EP children are at high risk for comorbid intellectual and learning disabilities. Education professionals should be aware of the complex nature of EP children's difficulties and the need for multi-domain assessments to guide intervention.

The Association Between Motor Skills and Academic Achievement Among Pediatric Survivors of Acute Lymphoblastic Leukemia

OBJECTIVE

Assess the association between fine motor (FM) and visual-motor integration (VMI) skills and academic achievement in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

In this 28-site cross-sectional study of 256 children in first remission, a mean of 8.9 ± 2.2 years after treatment for standard-risk precursor-B ALL, validated measures of FM, VMI, reading, math, and intelligence were administered at mean follow-up age of 12.8 ± 2.5 years. 

RESULTS

 VMI was significantly associated with written math calculation ability (p < .0069) after adjusting for intelligence (p < .0001). VMI was more strongly associated with math in those with lower intelligence (p = .0141). Word decoding was also significantly associated with VMI but with no effect modification by intelligence. FM skills were not associated with either reading or math achievement.

CONCLUSION

These findings suggest that VMI is associated with aspects of math and reading achievement in leukemia survivors. These skills may be amenable to intervention.

Executive Functioning and Learning Skills of Adolescent Children Born at Fewer than 26 Weeks of Gestation

Aims

To assess the cognitive and behavioral aspects of executive functioning (EF) and learning skills in extremely preterm (EPT) children compared with term control children aged 10 to 15 years.

Methods

A total of 132 of 134 (98% of all eligible survivors) EPT children born at the 2 Swedish regional tertiary care centers from 1992 to 1998 (mean age = 12 years, mean birth weight = 718 g, and mean gestational age = 24.4 weeks) and 103 matched term controls were assessed. General intelligence was assessed using the Wechsler Intelligence Scale for Children (WISC-III-R), and cognitive aspects of EF were analyzed using EF-sensitive subscales of the WISC-III-R and Tower test of the Delis-Kaplan Executive Function Scale (D-KEFS). Behaviors related to EF and learning skills were assessed using the Five to Fifteen questionnaire, which is a validated parent and teacher instrument. Academic performance in school was assessed by teachers’ responses on Achenbach’s Teachers Report Form. Analyses performed included multivariate analyses of covariance (ANCOVA and MANCOVA) and logistic regression analyses.

Results

The EPT children displayed significant deficits in cognitive aspects of EF compared with the controls, exhibiting decreases on the order of 0.9 SD to 1.2 SD for tasks of verbal conceptual reasoning, verbal and non-verbal working memory, processing speed and planning ability (P <0.001 for all). After excluding the children with major neurosensory impairment (NSI) or a Full Scale intelligence quotient (FSIQ) of < 70, significant differences were observed on all tests. Compared with controls, parents and teachers of EPT children reported significantly more EF-related behavioral problems. MANCOVA of teacher-reported learning skills in children with FSIQ >70 and without major NSI revealed no interactions, but significant main effects were observed for the behavioral composite executive function score, group status (EPT vs control) and FSIQ, for which all effect sizes were medium to large. The corresponding findings of MANCOVA of the parent-reported learning skills were very similar. According to the teachers’ ratings, the EPT children were less well adjusted to the school environment.

Conclusion

EPT children born in the 1990s who received active perinatal care are at an increased risk of executive dysfunction, even after excluding children with significant neurodevelopmental disabilities. Even mild to moderate executive dysfunctions has a significant impact on learning skills. These findings suggest the need for timely interventions that address specific cognitive vulnerabilities and executive dysfunctions.

Extended Production of Cortical Interneurons into the Third Trimester of Human Gestation

In humans, the developmental origins of interneurons in the third trimester of pregnancy and the timing of completion of interneuron neurogenesis have remained unknown. Here, we show that the total and cycling Nkx2.1(+)and Dlx2(+)interneuron progenitors as well as Sox2(+)precursor cells were higher in density in the medial ganglionic eminence (MGE) compared with the lateral ganglionic eminence and cortical ventricular/subventricular zone (VZ/SVZ) of 16-35 gw subjects. The proliferation of these progenitors reduced as a function of gestational age, almost terminating by 35 gw. Proliferating Dlx2(+)cells were higher in density in the caudal ganglionic eminence (CGE) compared with the MGE, and persisted beyond 35 gw. Consistent with these findings, Sox2, Nkx2.1, Dlx2, and Mash1 protein levels were higher in the ganglionic eminences relative to the cortical VZ/SVZ. The density of gamma-aminobutyric acid-positive (GABA(+)) interneurons was higher in the cortical VZ/SVZ relative to MGE, but Nkx2.1 or Dlx2-expressing GABA(+)cells were more dense in the MGE compared with the cortical VZ/SVZ. The data suggest that the MGE and CGE are the primary source of cortical interneurons. Moreover, their generation continues nearly to the end of pregnancy, which may predispose premature infants to neurobehavioral disorders.

The growth of very-low-birth-weight infants at 5 years old in Taiwan

BACKGROUND

The goal of this study was to compare the growth and effect of growth on cognitive performance at 5 years of age of a group of very-low-birth-weight (VLBW) infants and a group of healthy full-term infants.

METHODS

Beginning in 1995, under the sponsorship of the Premature Baby Foundation, the Society of Neonatology, Taiwan, conducted a multicenter follow-up study of VLBW infants in Taiwan. The study enrolled 322 VLBW infants and 103 controls for assessment of growth data and cognitive performance at several time points from birth through to 5 years of age. Growth data were assessed with measurements of weight, height, and head circumference taken at the ages of 6 months, 12 months, 24 months, and 60 months. Cognitive performance was assessed at the age of 5 years. The VLBW infants were regarded as "failed" if a measurement was 2 standard deviations below the mean measurement of the control group. Neonatal and perinatal data had been collected prospectively as part of a longitudinal study. Cognitive performance was assessed using the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-R).

RESULTS

From 6 months to 5 years, VLBW infants had lower weight, height, and head circumference than the controls. Two hundred twenty-four VLBW infants (69.6%) returned for assessment at 5 years old. Of the 224 VLBW infants, complete sets of measurements of weight, height, and head circumference were obtained for 126 cases (56.3%), 127 cases (56.7%), and 106 cases (47.3%), respectively. Of these, 13 patients (10.3%) failed in weight, 11 patients (8.7%) failed in height, and 17 patients (16.0%) failed in head circumference at the age of 5 years. The mean WPPSI-R scores at the age of 5 years for VLBW children were: 94.1 ± 16.4 (performance IQ), 87.2 ± 12.8 (verbal IQ), and 89.5 ± 14.6 (full IQ). All of these values were also lower than those of the control group, with the differences being statistically significant (p < 0.05). The WPPSI-R scores of VLBW children who failed in head circumference were notably lower than those of VLBW children whose head circumference had caught up with that of their peers.

CONCLUSION

The growth of VLBW infants was lower than that of healthy full-term infants through 5 years of age. The cognitive performance for VLBW children was also decreased compared to that of the control group, and there was an association between slower growth and decreased cognitive ability.

Preventing academic difficulties in preterm children: a randomised controlled trial of an adaptive working memory training intervention - IMPRINT study

Background

Very preterm children exhibit difficulties in working memory, a key cognitive ability vital to learning information and the development of academic skills. Previous research suggests that an adaptive working memory training intervention (Cogmed) may improve working memory and other cognitive and behavioural domains, although further randomised controlled trials employing long-term outcomes are needed, and with populations at risk for working memory deficits, such as children born preterm.

In a cohort of extremely preterm (<28 weeks’ gestation)/extremely low birthweight (<1000 g) 7-year-olds, we will assess the effectiveness of Cogmed in improving academic functioning 2 years’ post-intervention. Secondary objectives are to assess the effectiveness of Cogmed in improving working memory and attention 2 weeks’, 12 months’ and 24 months’ post-intervention, and to investigate training related neuroplasticity in working memory neural networks 2 weeks’ post-intervention.

Methods/Design

This double-blind, placebo-controlled, randomised controlled trial aims to recruit 126 extremely preterm/extremely low birthweight 7-year-old children. Children attending mainstream school without major intellectual, sensory or physical impairments will be eligible. Participating children will undergo an extensive baseline cognitive assessment before being randomised to either an adaptive or placebo (non-adaptive) version of Cogmed. Cogmed is a computerised working memory training program consisting of 25 sessions completed over a 5 to 7 week period. Each training session takes approximately 35 minutes and will be completed in the child’s home. Structural, diffusion and functional Magnetic Resonance Imaging, which is optional for participants, will be completed prior to and 2 weeks following the training period. Follow-up assessments focusing on academic skills (primary outcome), working memory and attention (secondary outcomes) will be conducted at 2 weeks’, 12 months’ and 24 months’ post-intervention.

Discussion

To our knowledge, this study will be the first randomised controlled trial to (a) assess the effectiveness of Cogmed in school-aged extremely preterm/extremely low birthweight children, while incorporating advanced imaging techniques to investigate neural changes associated with adaptive working memory training, and (b) employ long-term follow-up to assess the potential benefit of improved working memory on academic functioning. If effective, Cogmed would serve as a valuable, available intervention for improving developmental outcomes for this population.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12612000124831.

Behaviours related to executive functions and learning skills at 11 years of age after extremely preterm birth: a Swedish national prospective follow-up study

AIM

We investigated a national cohort of children born extremely immature (<26 weeks gestation, EI) regarding the nature, frequency and severity of the behavioural problems related to the executive functions (EF) and concerning learning skills, from the perspectives of parents and teachers.

METHODS

At 11 years of age 86 of 89 survivors of this cohort were studied and compared with an equal number of controls. Behaviours related to EF, and learning skills were assessed by a validated instrument, namely the Five to Fifteen questionnaire sent by mail to parents and teachers.

RESULTS

Compared with controls, parents of EI children reported significantly more problems in behaviours related to EF in all areas assessed (Attention, Hyperactivity/Impulsivity, Hypoactivity, Planning/Organizing, and Working Memory). Teachers' ratings showed a similar pattern. EI children also displayed deficient skills in the 4 standard measures of learning skills. Multivariate analysis revealed that prematurity, gender and behavioural composite score was associated with learning skills. Only a relatively small proportion of EI children (10-30%) exhibited clinically significant impairments.

CONCLUSION

Despite a favourable outcome in many school-age children born at the threshold of viability, these are at increased risk of developing behavioural problems related to EF.

Epileptogenesis: can the science of epigenetics give us answers?

Epigenetic mechanisms are regulatory processes that control gene expression changes involved in multiple aspects of neuronal function, including central nervous system development, synaptic plasticity, and memory. Recent evidence indicates that dysregulation of epigenetic mechanisms occurs in several human epilepsy syndromes. Despite this discovery of a potential role for epigenetic mechanisms in epilepsy, few studies have fully explored their contribution to the process of epilepsy development known as epileptogenesis. The purpose of this article is to discuss recent findings suggesting that the process of epileptogenesis may alter the epigenetic landscape, affecting the gene expression patterns observed in epilepsy. Future studies focused on a better characterization of these aberrant epigenetic mechanisms hold the promise of revealing novel treatment options for the prevention and even the reversal of epilepsy.

Visual cortical function in very low birth weight infants without retinal or cerebral pathology

PURPOSE

Preterm infants are at high risk of visual and neural developmental deficits. However, the development of visual cortical function in preterm infants with no retinal or neurologic morbidity has not been well defined. To determine whether premature birth itself alters visual cortical function, swept parameter visual evoked potential (sVEP) responses of healthy preterm infants were compared with those of term infants.

METHODS

Fifty-two term infants and 58 very low birth weight (VLBW) infants without significant retinopathy of prematurity or neurologic morbidities were enrolled. Recruited VLBW infants were between 26 and 33 weeks of gestational age, with birth weights of less than 1500 g. Spatial frequency, contrast, and vernier offset sweep VEP tuning functions were measured at 5 to 7 months' corrected age. Acuity and contrast thresholds were derived by extrapolating the tuning functions to 0 amplitude. These thresholds and suprathreshold response amplitudes were compared between groups.

RESULTS

Preterm infants showed increased thresholds (indicating decreased sensitivity to visual stimuli) and reductions in amplitudes for all three measures. These changes in cortical responsiveness were larger in the <30 weeks ' gestational age subgroup than in the ≥30 weeks' gestational age subgroup.

CONCLUSIONS

Preterm infants with VLBW had measurable and significant changes in cortical responsiveness that were correlated with gestational age. These results suggest that premature birth in the absence of identifiable retinal or neurologic abnormalities has a significant effect on visual cortical sensitivity at 5 to 7 months' of corrected age and that gestational age is an important factor in visual development.

Impact at age 11 years of major neonatal morbidities in children born extremely preterm

BACKGROUND

Uncertainty continues regarding the extent to which neonatal morbidities predict poor long-term outcome and functional abilities in extremely preterm infants.

OBJECTIVE

The goal of this study was to determine the impact of bronchopulmonary dysplasia (BPD), ultrasonographic signs of brain injury, and severe retinopathy of prematurity (ROP) on 11-year outcomes in infants born at <26 weeks' gestation.

METHODS

A total of 247 infants were born alive before 26 completed weeks of gestation from 1990 through 1992 in all of Sweden, and 98 (40%) survived to a postmenstrual age of 36 weeks. Main outcome measures were (1) poor outcome, defined as combined end point of death after 36 weeks' postmenstrual age or survival with at least 1 major disability at 11 years, and (2) consequences of chronic conditions in the survivors according to a validated instrument administered to parents.

RESULTS

Brain injury and severe ROP but not BPD correlated independently with poor outcome at 11 years of age. Among children who were free from BPD, brain injury, and severe ROP, 10% had a poor outcome. Corresponding rates with any 1, any 2, and all 3 neonatal morbidities were 19%, 58%, and 80%, respectively. Multivariate analysis revealed that brain injury and severe ROP were associated with high rates of consequences of chronic conditions.

CONCLUSIONS

In infants born extremely preterm who survive to a postmenstrual age of 36 weeks, severe ROP and brain injury separately predict the risk of death or major disability at 11 years of age. Thus, continued research to determine how to prevent these complications of prematurity is critical.

Birth weight and cognitive performance in older women: the Rancho Bernardo study

Low birth weight is associated with poorer cognitive function from infancy through early adulthood, but little is known about low birth weight and cognitive performance in the elderly. This study examines the association of birth weight with cognitive function in community-dwelling older women. Participants were 292 community-dwelling women aged 55-89 (median = 71 years) who attended a 1988-91 clinic visit when cognitive function was assessed, and responded to a 1991 mailed questionnaire assessing birth weight. All analyses were adjusted for age and education. Birth weight ranged from 2 to 12 pounds (lbs; mean = 7.4 +/- 1.9). When birth weight was categorized into tertiles (2-6.9 lbs, 7-8 lbs, and 8.1-12.4 lbs), women in the lowest tertile had significantly lower ("poorer") scores on Serial 7's, a test of concentration and calculation (p < 0.05). Other birth weight categorizations (lowest quartile or quintile, or birth weight <5.5 lbs vs. 5.6-8.9 lbs and >or=9 lbs) did not improve the prediction of poor performance on Serial 7's. Birth weight as a continuous variable was significantly and positively associated with Serial 7's test scores (p = 0.04). Results suggest that small decrements in cognitive function tasks involving calculation may persist throughout life in women who were of relatively low birth weight. Although this association could be spurious, it deserves further evaluation.

Extreme prematurity and neuropsychological outcome in the preschool years

With the increasing survival of extremely preterm (EP) birth infants in the surfactant era, the longer-term outcome of infants born at the threshold of viability has become a vital topic of study. The goal of this investigation was twofold. First, while taking into account the influence of sociodemographic confounds, we wished to investigate neuropsychological outcome differences between two groups of EP preschoolers: 23-24 weeks (n = 20), and 25-26 weeks' (n = 21) gestation at delivery. Second, we wished to explore whether, within the population of EP preschoolers, gestational maturity accounts for a unique portion of the variance in neuropsychological outcome, over and above the variance explained by ante-, peri-, and neonatal complications, or treatment factors. The findings revealed group differences, ranging from .70 to .80 of a standard deviation in general intellectual abilities, nonverbal intelligence, and global motor performance, in favor of the more mature EP group. Additionally, gestational maturity was found to explain a unique portion of the variance in global intellectual and motor abilities. These findings are interpreted from the perspective that gestational age is an index of the vulnerability of the central nervous system to disruption of developmentally regulated processes.

Growth mixture modeling of academic achievement in children of varying birth weight risk

The extremes of birth weight and preterm birth are known to result in a host of adverse outcomes, yet studies to date largely have used cross-sectional designs and variable-centered methods to understand long-term sequelae. Growth mixture modeling (GMM) that utilizes an integrated person- and variable-centered approach was applied to identify latent classes of achievement from a cohort of school-age children born at varying birth weights. GMM analyses revealed 2 latent achievement classes for calculation, problem-solving, and decoding abilities. The classes differed substantively and persistently in proficiency and in growth trajectories. Birth weight was a robust predictor of class membership for the 2 mathematics achievement outcomes and a marginal predictor of class membership for decoding. Neither visuospatial-motor skills nor environmental risk at study entry added to class prediction for any of the achievement skills. Among children born preterm, neonatal medical variables predicted class membership uniquely beyond birth weight. More generally, GMM is useful in revealing coherence in the developmental patterns of academic achievement in children of varying weight at birth and is well suited to investigations of sources of heterogeneity.

Early school-based learning difficulties in children born very preterm

BACKGROUND

Educational underachievement is a major morbidity associated with very preterm (VPT) birth. However, few studies have examined early school outcomes with most employing global, clinic based measures.

OBJECTIVE

To examine the early school achievement in a cohort of children born VPT and studied to age 6 years.

METHODS

A regional cohort of 102 VPT children (</=33 weeks GA) were followed prospectively alongside a comparison group of 108 full term (FT) children born during the same period (1998-2000). At 6 years corrected age, all children underwent a comprehensive neurodevelopmental evaluation that included the Woodcock-Johnson Tests of Achievement (WJ-III), teacher report and national numeracy and literacy test results. Rates of specific learning disabilities (LD) were also examined.

RESULTS

VPT children performed less well than FT children on WJ-III subtests (ps<.05), national tests (ps<.01), and in all curricular areas rated by teachers (ps<.01) except expressive language. Even VPT children without severe neurodevelopmental impairment scored lower on the WJ-III math, national tests (ps<.05) and were 2-3 times more likely to show delays (ps<.02) in math (43% vs. 19%), written language (36% vs. 22%), language comprehension (26% vs. 14%), handwriting (36% vs. 17%), spelling (38% vs. 30%) and physical education (33% vs. 11%). They were also twice as likely as FT children to have math LD (47% vs. 21%).

CONCLUSIONS

By age 6, a substantial proportion of VPT children are lagging behind their FT peers across multiple curriculum areas, with difficulties being most prominent in math. Findings highlight the need for early identification and educational supports to help maximise VPT children's learning opportunities during the transition to school.

The role of transient hypothyroxinemia of prematurity in development of visual abilities

Preterm birth is associated with an increased risk of visual impairment. However, not all visual deficits can be fully explained by the typical prematurity morbidity factors. In addition, children born preterm often exhibit transient hypothroxinemia of prematurity (THOP) due to premature severing of the maternal supply of thyroid hormones. Because thyroid hormone is critically needed for multiple facets of early brain development, including the structures needed for visual processing, and because the maternal thyroid supply is essential throughout pregnancy, it is possible that THOP contributes to the visual impairments seen in preterm children. To test this hypothesis, we used both clinical tests and visual-evoked potential techniques to assess visual abilities in two cohorts of preterm infants whose thyroid hormone levels were measured in the perinatal period. In the first cohort born 30 to 35 weeks gestation, we found associations between low thyroid hormone levels and reduced visual attention at 3 months corrected age (Study 1) and poor visuomotor abilities at 12 and 18 months corrected age (Study 2). In the second cohort born 23 to 35 weeks gestation, THOP severity was negatively correlated with attention at 3 months corrected age (Study 3) and contrast sensitivity and color vision at 6 months corrected age (Study 4). These findings therefore suggest that thyroid hormone is necessary for the development of early visual abilities and that THOP may partially explain the visual deficits of preterm infants.

Motor impairment and low achievement in very preterm children at eight years of age

AIM

To examine the concurrence of motor impairment and academic underachievement in a group of very preterm children at 8 years of age.

METHODS

All surviving children with a gestational age less than 30 weeks, admitted to the neonatal intensive care unit between 1987 and 1997, were prospectively enrolled in developmental follow-up. Children with a neurosensory disability or a low intelligence score (FSIQ < or = 75 points) were excluded. At 8 years of age the Bruininks Oseretsky Test of Motor Proficiency and standardised tests of academic achievement were administered to a sample of 323 very preterm children.

RESULTS

One hundred and one (31.3%) of these very preterm children were identified as having Developmental Coordination Disorder (DCD). Of the children with DCD, 54.4% also had underachievement in literacy and/or numeracy. As the severity of motor impairment increased so too did the severity and complexity of underachievement. Significantly fewer children with motor impairments participated in after-school sporting activities. Children with DCD required more mechanical ventilation support during their hospital admission.

CONCLUSIONS

This study demonstrated that a significant proportion of children born very preterm find both motor and academic skills difficult in early school years.

Cognitive and educational deficits in children born extremely preterm

A large body of research indicates that children born very preterm are at increased risk for neurobehavioral impairments; however, research examining outcome for extremely preterm (EP) children is limited. This chapter will review the literature focusing on early development delay, general intellectual functioning, specific cognitive skills, basic educational skills, and behavioral and emotional functioning in children born <26 weeks' gestation or with a birth weight <750 g. Findings are generally consistent and indicate that a large proportion of EP children and their families will face major challenges, including significant development delay, cognitive impairments, learning disabilities, and behavioral and emotional problems. However, a considerable proportion of these high-risk children will escape major impairments, and this variability in outcome is thought to be related to genetic (gender), perinatal (brain injury, bronchopulmonary dysplasia), and social-environmental (social risk, parenting) factors.

Perinatal pH and neuropsychological outcomes at age 3 years in children born preterm: an exploratory study

The impact of extreme prematurity and related hypoxic-ischemic events on brain development recently has begun to be characterized with modern neuroimaging methods, although comparatively less is known about the neuropathology in those born at heavier birth weights. Even subclinical levels of perinatal hypoxia-ischemia, as indexed by perinatal blood pH, are related to intelligence in school-aged children born preterm. Given the impact of hypoxia-ischemia on white matter and the emerging evidence of specific executive and mathematic deficits in children born preterm, the impact of perinatal hypoxia-ischemia on these outcomes was explored in children at relatively low-risk for sequelae. In a sample of 22 preschool children born preterm, arterial blood pH values obtained within the first 3 h of life were abstracted from review of hospital medical charts, and then related to specific cognitive task performance at age 3 years. Mean initial pH was in the normal to subclinical range. Initial pH appears to be a strong predictor of specific mathematics and controlled attention abilities, and is not limited to general verbal ability alone. However, initial pH was not related to performance on measures of motor impulsivity or working memory. As a screening index of subtle hypoxia-ischemia, these findings suggest that perinatal arterial blood pH warrants further study as a potential marker of subtle hypoxic-ischemic injury that likely affects cognitive outcome throughout childhood in those at risk due to preterm birth.

Phonology, rapid naming and academic achievement in very preterm children at eight years of age

AIM

To examine the impact and additive effect of phonology and rapid naming deficits on reading, spelling and mathematics achievement in a group of very preterm children at 8 years of age.

METHODS

All surviving children with a gestational age less than 30 weeks, admitted to the neonatal intensive care unit at Royal Prince Alfred Hospital, in 1994 and 1995, were prospectively enrolled in developmental follow-up. Children with a neurosensory disability or a low intelligence score (FSIQ<or=85 points) were excluded. At 8 years of age standardised psychometric measures of cognition, linguistic ability and academic achievement were administered to a sample of 63 children.

RESULTS

Twenty-four (38.1%) children showed low achievement in reading, spelling or mathematics. Of these, 18 (75%) children showed low achievement in reading. Reading achievement was significantly correlated to phonological awareness, rapid naming and expressive vocabulary. Children with phonological awareness and rapid naming deficits showed significantly more delay in reading than children without such deficits. Children who had rapid naming deficits were more likely to show multiple skill delays. Rapid naming showed significant, though modest correlations with immaturity and illness variables. Maternal education was significantly associated with achievement.

CONCLUSIONS

Phonological awareness does predict reading performance in very preterm children. Rapid naming appears to be related to complex multiple academic delays, and may reflect a neurological timing or efficiency factor with effects independent of intelligence and significantly influenced by immaturity and illness.

Visual development in very low birth weight infants

Extremely preterm infants are at risk for neurodevelopmental problems and the visual system is particularly vulnerable. However, development of visual function in preterm infants with little or no retinal or neurologic injury has not been well defined. This study compared development of visual function in preterm infants without severe retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL) to that of term infants at 5-7 mo corrected age. Twenty-one very low birth weight (VLBW) preterm infants (24-32 wk gestational age, weighing < 1500 g), and 22 healthy term infants were tested at 5-7 mo corrected age. Infants with any IVH/PVL and > Stage II ROP or Plus disease were excluded. Contrast sensitivity, grating acuity, and vernier acuity were measured using swept-parameter visual evoked potentials. Thresholds and maximum amplitudes were compared between groups. VLBW and term infants showed no differences in sensitivity for contrast (67.5 versus 63.8), grating resolution (12.4 versus 12.5 cpd) or vernier acuity (1.2 versus 1.0 arcmin). However, the amplitudes for swept contrast (p < 0.03) and swept vernier offset (p < 0.04) stimuli were higher in VLBW infants. Visual thresholds in VLBW infants without serious retinal or neurologic abnormalities were not significantly different from those of term infants, suggesting that increased visual experience does not influence visual sensitivity. The higher amplitudes in VLBW infants, suggests that visual experience may affect responses to suprathreshold stimuli.

Subnormal head circumference in very low birth weight children: neonatal correlates and school-age consequences

BACKGROUND

Subnormal head circumference (HC) has been associated with poor neurologic and developmental outcomes.

AIM

To examine the correlates and consequences of subnormal HC in a cohort of school age, very low birth weight (VLBW, <1,500 g) children. STUDY DESIGN AND OUTCOME MEASURES: We examined developmental outcomes at a mean age of 6.8 years in a cohort of 128 VLBW children born from 1982-1986 and 58 normal birth weight controls. The VLBW cohort included a regional sample of <750 g birth weight children and matched children with 750-1,499 g birth weight. Outcomes included an IQ equivalent, neuropsychological skills, academic achievement, adaptive behavior, and attention problems. HC was defined along a continuum and as subnormal vs. normal. Linear and logistic regressions were employed to determine the effects of HC on the outcomes after controlling for confounding variables.

RESULTS

Thirty one VLBW children (24%) had subnormal HC vs. none of the controls. The VLBW children with subnormal HC differed significantly from the normal HC group in birth weight (748 g vs. 977 g, p<.001), SGA status (52% vs. 27%, p<.05), high neonatal risk (57% vs. 29%, p<.05), and neurosensory impairment (23% vs. 8%, p<.05). Even after taking these risk factors into account, subnormal HC was associated with poorer IQ equivalent, perceptual motor skills, academic achievement, and adaptive behavior. Results were similar after excluding the children with neurosensory impairment.

CONCLUSIONS

Subnormal HC is associated with adverse developmental outcomes in VLBW children, independent of other risk factors. Interventions to improve antenatal and postnatal growth may contribute to better school-age outcomes.

A longitudinal study of reading skills among very-low-birthweight children: is there a catch-up?

OBJECTIVE

To examine the development of reading skills among very-low-birthweight (VLBW) children and to what extent reading difficulties at 9 years of age persist unchanged, are attenuated, or are enhanced at 15 years of age.

METHODS

Fifty-six VLBW and 52 normal birthweight (NBW) children were assessed on word decoding, word recognition, and reading comprehension at 9 and 15 years of age.

RESULTS

VLBW children showed deficits in reading skill at 9 years of age, while most differences obtained at 15 years of age did not reach significance. VLBW children improved their reading comprehension between 9 and 15 years of age more than NBW children, and when controlling for individual differences in IQ, VLBW children improved both their reading comprehension and word-recognition skill.

CONCLUSION

The results suggest that VLBW children display positive changes over time in reading skills.

Longitudinal Changes in Family Outcomes of Very Low Birth Weight

OBJECTIVES

Although children with very low birth weight (VLBW, <1500 g) are at high risk for developmental impairments, we know little about the long-term effects of VLBW on families. This study examined long-term family outcomes and their stability over time.

METHODS

Participants were the families of 64 children with <750 g birth weight, 54 with 750-1499 g birth weight, and 66 term-born controls. Family burden and parental distress were assessed annually as part of longitudinal follow-up of the children from mean ages 11-14 years.

RESULTS

Family burden and parental distress were higher in the <750 g group than in the term-born group, but differences varied with the child's age and family environment.

CONCLUSIONS

The findings document long-term effects of VLBW on families that are moderated by the degree of low birth weight, child's age, and family environment.

Learning disabilities in children with very low birthweight: prevalence, neuropsychological correlates, and educational interventions

This study examined achievement, neuropsychological, and intervention outcomes at a mean age of 11 years in children with very low birthweight (VLBW, <1500 g) compared with a term-born control group. To assess the prevalence and correlates of specific learning disabilities (LD), the sample was limited to children without neurosensory disorders who had at least low average IQ. Participants included 31 children with <750 g birthweight, 41 with 750-1499 g birthweight, and 52 controls. The <750 g group obtained lower scores in math, IQ, and perceptual-organizational skills than the term-born group. The < 750 g group also had higher rates of past and present LD than the controls. Despite these differences, the groups did not differ significantly in rates of special education or tutorial/remedial assistance. These findings suggest that children with extremely low birthweight without gross physical or intellectual impairments are at higher risk for LD and cognitive deficiencies than their term-born peers and that further efforts are needed to improve identification and treatment of these learning problems.

Neonatal procedural pain and preterm infant cortisol response to novelty at 8 months

OBJECTIVES

Stress systems may be altered in the long term in preterm infants for multiple reasons, including early exposure to procedural pain in neonatal intensive care. This question has received little attention beyond hospital discharge. Stress responses (cortisol) to visual novelty in preterm infants who were born at extremely low gestational age (ELGA; < or =28 weeks), very low gestational age (VLGA; 29-32 weeks), and term were compared at 8 months of age corrected for prematurity (corrected chronological age [CCA]). In addition, among the preterm infants, we evaluated whether cortisol levels at 8 months were related to neonatal exposure to procedural pain and morphine in the neonatal intensive care unit.

METHODS

Seventy-six infants, 54 preterm (< or =32 weeks' GA at birth) and 22 term-born infants who were seen at 8 months CCA composed the study sample, after excluding those with major sensory, motor, or cognitive impairment. Salivary cortisol was measured before (basal) and 20 minutes after introduction of novel toys (post 1) and after developmental assessment (post 2).

RESULTS

Salivary cortisol was significantly higher in ELGA infants at 8 months, compared with the VLGA and term groups before and after introduction of visual novelty. Term-born and VLGA infants showed a slight decrease in cortisol when playing with novel toys, whereas the ELGA group showed higher basal and sustained levels of cortisol. After controlling for early illness severity and duration of supplemental oxygen, higher basal cortisol levels in preterm infants at 8 months' CCA were associated with higher number of neonatal skin-breaking procedures. In contrast, cortisol responses to novelty were predicted equally well by neonatal pain or GA at birth. No relationship between morphine dosing and cortisol response was demonstrated in these infants.

CONCLUSIONS

ELGA preterm infants show a different pattern of cortisol levels before and after positive stimulation of visual novelty than more maturely born, VLGA preterm and term-born infants. Exposure to high numbers of skin-breaking procedures may contribute to "resetting" basal arousal systems in preterm infants.

Germinal matrix-intraventricular hemorrhage in the premature newborn: management and outcome

Germinal matrix-intraventricular hemorrhage (GMH-IVH) in the premature newborn results from rupture of fragile capillaries in the germinal matrix. Its pathogenesis is multifactorial and relates principally to a pressure-passive cerebral circulation, fluctuations in cerebral blood flow, and derangements of coagulation and fragility of the germinal matrix microvasculature. Several interventions have beneficial effects for prevention of GMH-IVH. Outcome after GMH-IVH relates largely to the severity of hemorrhage, the extent of hemorrhagic and ischemic parenchymal involvement, and complications (e.g., posthemorrhagic hydrocephalus). Even in the absence of neuroimaging abnormalities, VLBW infants have a high incidence of academic and behavioral problems which persist into adolescence and early adulthood.

Special education services and school performance in a regional cohort of low-birthweight infants at age nine

Previous research has shown that low birthweight is a predictor of several adverse educational outcomes, including special educational placement, by middle school age. Most low-birthweight follow-up studies that have extended to school age have focused on very small infants-- < 1500 or < 1000 g; less is known of the school age outcomes for infants with only moderately low birthweight (1500-2000 g). This study examines the prevalence of special educational placement and the relationship of such placement to grade retention, verbal and performance scores on tests of general intelligence, reading and maths achievement scores and classroom hyperactivity among low-birthweight children. In a regional birth cohort of 1105 infants born between 1984 and 1987 and weighing 500-2000 g, 868 children were available for follow-up at age nine. Information on special education placement as well as grade retention, intelligence, academic achievement and classroom behaviour was available on 645 (74% completion rate). Nearly a third of the cohort was classified as needing special education. Special education placement followed a birthweight gradient, occurring among 29.3% of children with birthweights 1500-2000 g, among 32.5% in children 1000-1500 g and 49.4% in children < 1000 g. Among children in special education, a similar birthweight gradient was found for maths achievement and hyperactivity, but not for reading achievement or IQ scores. Among children not in special education, only maths achievement showed such a decline with birthweight. A substantial proportion of low-birthweight children, including those of moderate low birthweight, receive special education services, although the need is greatest among those with the lowest birthweights. Maths achievement declined with birthweight regardless of educational placement. The medical and social risk factors that accompany low birthweight and may account for these findings, require further study.

Management decisions in extremely premature infants

Survival rates in excess of 25% at 23 weeks' gestation and in excess of 50% at 24 weeks' gestation have been reported among live births in the 1990s within tertiary perinatal care centres in the USA and Australia. Decisions about medical management at these gestational ages can no longer be based merely on whether survival is possible. Relevant moral considerations include the primacy of the newborn's best interests, parental autonomy, physicians' duties of beneficence and non-maleficence, and distributive justice. There is significant variability between developed nations in the survival of extremely premature infants among cohorts born within perinatal tertiary care centres. This is, at least to some degree, the result of differences in the aggressiveness of obstetrical and neonatal management at these gestational ages. There is also great variability in the prevalence of major neurodevelopmental disability among survivors. Moreover, the prevalence of major disabilities does not inform quality-of-life considerations adequately. Despite similar gestational age ranges over which the benefit:burden ratio of aggressive obstetric and neonatal care is questioned in developed countries, there is marked variation in the frequency with which it is provided within these ranges. This is understandable given the relevant moral values and the different ways in which competing values will be balanced by different individuals, cultures and societies; the increasing survival of extremely premature infants, but the persistence of high (but widely variable) prevalences of major disabilities reported among survivors and even higher prevalences of mild-to-moderate neurodevelopmental sequelae; our imperfect ability to estimate an individual extremely premature infant's prognosis; and the complexities of estimating the quality of life from the individual's own perspective.

The use of the QNST-II as a measure for the identification of children with perceptual-motor deficits

This study aimed to examine the ability of the Quick Neurological Screening Test QNST II) (Mutti et al., 1998) to discriminate between children with and without perceptual-motor deficits and to further clarify its psychometric characteristics. Ninety-four children aged six to seven years were tested on the QNST-II. Out of this pool of subjects, 63 children had perceptual-motor deficits and 31 were typical controls. The children with perceptual-motor deficits scored significantly lower than the control children on the total score and on each of the subtest' s scores of the QNST II. Inter-rater reliability indicated a high degree of correlation between both evaluators' total scores of the QNST II. In terms of the test' s sensitivity and specificity, QNST II scores correctly classified 97% of the children with perceptual-motor deficits and 84% of the children from the control group. The findings of this study support the capability of the QNST II to discriminate between children with perceptual-motor deficits and typical children; thereby suggesting its usefulness as a screening measure to identify children at risk for difficulties in school performance.

Environmental effects on language development in normal and high-risk child populations

This report describes language development from infancy through 8 years of life for a large sample of very low birth weight (VLBW) (high medical risk, n = 94; low medical risk, n = 132) and term (n = 134) children. Children of high and low medical risk status showed lower levels and slower rates of development compared with term children. Although these children also showed nonverbal cognitive deficits, their language difficulties appeared to be independent of these general cognitive problems. Although lower socioeconomic status (SES) showed strong negative effects on rate of language development, this was comparable across the three risk groups. Within this generally lower SES sample of children, the type of interactive behaviors caregivers used in early childhood showed significant relations to skill growth. Children with faster rates of language growth had mothers who maintained their interests more often and were less likely to use highly directive behaviors.

Beeinträchtigte kognitive und motorische Leistungen bei 8jährigen Kindern mit sehr niedrigem Geburtsgewicht

Zusammenfassung. Theoretischer Hintergrund: Es ist belegt, daß VLBW-Kinder (< 1500g) vermehrt motorische und/oder geistige Behinderungen aufweisen. Dagegen werden subtilere Beeinträchtigungen ohne offensichtliche Behinderung kontrovers diskutiert. Fragestellung: Das kognitive Leistungsprofil und grobmotorische Fertigkeiten von 33 neurologisch unauffälligen 8jährigen VLBW-Kindern werden mit 224 NBW-Kindern (≥ 2500g) verglichen. Methode: Die Daten resultieren aus einer prospektiven Längsschnittstudie mit 362 Kindern mit unterschiedlicher organischer und psychosozialer Risikobelastung. Ergebnisse: Nonverbale Funktionen der VLBW-Gruppe fielen signifikant schlechter als in der NBW-Gruppe aus, während verbale Fähigkeiten unauffällig waren. Unabhängig vom Geburtsgewicht beeinträchtigte eine hohe psychosoziale Belastung ausschließlich sprachliche Leistungen. Intraindividuelle Profilanalysen der VLBW-Gruppe ergaben keine spezifischen Defizite. Schlußfolgerung: Die Ergebnisse unterstützen die Annahme von suboptimalen rechtshemisphärischen Funktionen bei VLBW-Kindern sowie eine additive Verknüpfung von psycho-sozialer Belastung und niedrigem Geburtsgewicht.

Auditory temporal processing deficits in children with periventricular brain injury

The present study investigated whether auditory temporal processing deficits are related to the presence and/or the severity of periventricular brain injury and the reading difficulties experienced by extremely low birthweight (ELBW: birthweight <1000 g) children. Results indicate that ELBW children with mild or severe brain lesions obtained significantly lower scores on a test requiring auditory temporal order judgments than ELBW children without periventricular brain injury or children who were full-term. Structural equation modeling indicated that a model in which auditory temporal processing deficits predicted speech sound discrimination and phonological processing ability provided a better fit for the data than did a second model, which hypothesized that auditory temporal processing deficits are associated with poor reading abilities through a working memory deficit. These findings suggest that an impairment in auditory temporal processing may contribute to the reading difficulties experienced by ELBW children.

An intervention for children with disorders of executive functions

This article describes a cognitive-behavioral approach to teaching metacognitive executive thinking strategies to children with disorders of executive function. The intervention is based on the notion that some children with disorders of executive function have disorders of higher level language, which predispose them to the executive impairments. It is proposed that teaching and reinforcing metacognitive thinking strategies may help advance verbal mediation of complex tasks and self-regulation of behavior. Despite the growing literature on developmental executive disorders, little has been written about interventions that may enable the children to acquire some of the requisite adaptive skills. The ideas expressed herein should be considered an invitation for the initiation of empirical studies of intervention and outcome effects.

The outcome of extreme prematurity

Significant advances in perinatology and neonatology in the last decade have resulted in increased survival of extremely premature infants. Survival rates for infants born in tertiary perinatal and neonatal care centers in the United States in the 1990s increase with each week of gestational age from 22 through 26 weeks. Reported survival rates at 22 weeks range from 0% to 21% in the few reporting studies. Reported survival rates at 23 and 24 weeks range from 5% to 46% and from 40% to 59%, respectively. These may not be the maximum survival rates possible because at these gestational ages information is either insufficient to determine that obstetric and neonatal intensive care strategies to maximize neonatal survival were used or it is specified that such strategies were not used. Reported survival rates at 25 and 26 weeks range from 60% to 82% and from from 75% to 93%, respectively. The literature regarding the prevalence of major neurodevelopmental disabilities among extremely premature survivors in the last 25 years is heteogeneous, and the reported prevalances of major disability vary much more than do survival rates. However, the majority of extremely premature infants who survive will be free of major disability. Overall, approximately one fifth to one quarter of survivors have at least one major disability-impaired mental development, cerebral palsy, blindness, or deafness. Impaired mental development is the most prevalent disability (17%-21% [95% CI] of survivors affected), followed by cerebral palsy (12%-15% of survivors affected). Blindness and deafness are less common (5% to 8% and 3% to 5% of survivors affected, respectively). Approximately one half of disabled survivors have more than one major disability. Based on studies of infants less than 750 to 1,000 grams birth weight, it can be anticipated that approximately another half of all extremely premature survivors will have one or more subtle neurodevelopmental disabilities in the school and teenage years. There is little evidence to suggest that long-term neurodevelopmental outcome has changed from the late 1970s to the early 1990s or with increasing survival. Survival of individual extremely premature infants cannot be accurately predicted in the immediate perinatal period. Major disability cannot be accurately predicted for individual survivors during the course in the newborn intensive care unit.

Academic achievement of low birthweight children at age 11: the role of cognitive abilities at school entry

We examine the extent to which deficits in academic achievement in low birthweight (LBW) children at age 11 are explained by deficits in cognitive abilities at school entry. Data come from a longitudinal study of a stratified sample of LBW and normal birthweight (NBW) children from an innercity and middle class suburbs in the Detroit area. Woodcock-Johnson Psychoeducational Battery-Revised was used to measure reading and math at age 11. WISC-R and specific neuropsychologic tests were administered at age 6. On reading, the LBW-NBW difference was -3.6 points (SE = 1.2). The difference was explained almost entirely by IQ at age 6. On math, the LBW-NBW difference was -6.1 points (SE = 1.1). The difference on math was trivial and not significant, when IQ and neuropsychological tests at age 6 were controlled. Level of LBW was unrelated to reading, but it had a gradient relationship with math, with birthweight < or = 1,500 g associated with a greater deficit than heavier LBW. The results imply that most of the LBW-NBW gap in academic achievement at age 11 could be eliminated by eliminating differences in cognitive abilities at age 6. Interventions to improve academic performance of LBW children should focus on the preschool years.

Aspectos cognitivos e comportamentais na média meninice de crianças nascidas pré-termo e com muito baixo peso

O objetivo deste estudo consiste em avaliar o desenvolvimento cognitivo e o comportamento de 20 crianças de 8 a 10 anos nascidas pré-termo e baixo peso (<= 1500g) no HCFMRP. Na avaliação cognitiva utilizou-se o RAVEN, o WISC e a avaliação assistida e na avaliação do comportamento utilizou-se a Escala de Rutter. Verificou-se que as crianças apresentaram desempenho intelectual na média, tendendo ao rebaixamento cognitivo. Na avaliação cognitiva assistida, a maior parte das crianças foi classificada como "ganhadora" e foram capazes, com a ajuda da examinadora, de implementar e manter estratégias eficientes para a resolução do problema. Quanto ao comportamento, foram detectados índices sugestivos de necessidade de atendimento psicológico para a maioria das crianças. Verificaram-se correlações significativas entre os resultados das avaliações cognitivas entre si e entre estas e a do comportamento. Os resultados apontam para a necessidade de seguimento psicológico longitudinal desse grupo de risco para problemas de desenvolvimento.

School-age consequences of birth weight less than 750 g: a review and update

Recent advances in perinatal care have led to the survival of increasing numbers of children born at the lower limits of viability. Children with very low birth weight (LBW; less than 1,500 g, 3 lb 5 oz) have been studied extensively. Findings document poorer outcomes relative to normal birth weight term-born controls in neurologic and health status, cognitive-neuropsychological skills, school performance, academic achievement, and behavior. This report reviews current knowledge regarding LBW children, with special emphasis on outcomes for children with birth weight less than 750 g (1 lb 10 oz). Results from an ongoing longitudinal study suggest a gradient of sequelae, with poorer outcomes in less than 750 g birth weight children compared to both 750 g to 1,499 g birth weight children and term-born controls. Children with less than 750 g birth weight fail to catch up with their peers over time and may even be at risk for age-related increases in sequelae. Outcomes are highly variable but related to neonatal medical complications of prematurity and social risk factors. Further research is needed to understand the etiology and neuropathological basis of sequelae, the long-term developmental implications of LBW, and treatment needs.

Functional limitations and special health care needs of 10- to 14-year-old children weighing less than 750 grams at birth

OBJECTIVE

To examine the health status, functioning, and special health care needs of children 10 to 14 years old weighing <750 g at birth.

METHODS

We compared outcomes of a regional cohort of 59 children born from 1982 through 1986 weighing <750 g at birth (mean: 665 g; gestational age: 26 weeks) to matched groups of 54 children weighing 750 to 1499 g at birth and 49 children born at term. Assessments of limitations in functioning, compensatory dependence and needs for services above routine, at a mean age of 11 years, were based on responses to maternal questionnaires. Rates of these outcomes were compared between groups using logistic regression analyses that controlled for gender and social risk.

RESULTS

Children weighing <750 g at birth had significantly higher rates of functional limitations, greater compensatory dependence, and need for services above routine than the other 2 groups. Compared with children born at term, the odds ratio for mental or emotional delay was 4.7 (95% confidence interval [CI]: 2.0-11.0), for restrictions in activity, 5.1 (CI: 1.6-16.3) and for blindness or difficulty seeing 3.9 (CI:1.3-11.4). With the exception of 3% of children who were severely impaired, the only compensatory aid that differentiated the children weighing <750 g at birth from the children born at term was the greater need for glasses (odds ratio [OR]: 2.8 [CI: 1.3-6.3]). Increased services above routine included special education (OR: 5.0 [CI: 2.1-11.7]), counseling (OR: 4.8 [CI: 1.0-23.1]) and special arrangements in school (OR: 9.5 [C.I. 2.1-43. 6]).

CONCLUSION

Parents and educators need to be informed of the potential for disability and special health care needs of children weighing <750 g at birth.

Behavior, pain perception, and the extremely low-birth weight survivor

This article explores the literature concerning responses to pain of both premature and term-born newborn infants, the evidence for short-term and long-term effects of pain, and behavioral sequelae in individuals who have experienced repeated early pain in neonatal life as they mature. There is no doubt that pain causes stress in babies and this in turn may adversely affect long-term neurodevelopmental outcome. Although there are methods for assessing dimensions of acute reactivity to pain in an experimental setting, there are no very good measures available at the present time that can be used clinically. In the clinical setting repeated or chronic pain is more likely the norm rather than infrequent discrete noxious stimuli of the sort that can be readily studied. The wind-up phenomenon suggests that, exposed to a cascade of procedures as happens with clustering of care in the clinical setting in an attempt to provide periods of rest for stressed babies, an infant may in fact perceive procedures that are not normally viewed as noxious, as pain. Pain exposure during lifesaving intensive medical care of ELBW neonates may also affect subsequent reactivity to pain in the neonatal period, but behavioral differences are probably not likely to be clinically significant in the long term. Prolonged and repeated untreated pain in the newborn period, however, may produce a relatively permanent shift in basal autonomic arousal related to prior NICU pain experience, which may have long-term sequelae. In the long run, the most significant clinical effects of early pain exposure may be on neurodevelopment, contributing to later attention, learning, and behavior problems in these vulnerable children. Although there is considerable evidence to support a variety of adverse effects of early pain, there is less information about the long-term effects of opiates and benzodiazepines on the developing central nervous system. Current evidence reviewed suggests that judicious use of morphine for adjustment to mechanical ventilation may ameliorate the altered autonomic response. It may be very important, however, to distinguish stress from pain. Animal evidence suggests that the neonatal brain is affected differently when exposed to morphine administered in the absence of pain than in the presence of pain. Pain control may be important for many reasons but overuse of morphine or benzodiazepines may have undesirable long-term effects. This is a rapidly evolving area of knowledge of clear relevance to clinical management likely to affect long-term outcomes of high-risk children.

Follow-up of very low birthweight babies to adolescence

Reports on the school-age outcomes and behavioural difficulties at adolescence of infants who were very low birthweight (VLBW) are only just emerging. Studies which compare VLBW with same age controls consistently show significantly poorer performance, with average scores between 8 and 13 points lower. Even children with no neurological impairments have scores which are significantly lower on cognitive and achievement measures. The extremely low birthweight (ELBW) adolescents fare worse on all measures and perform particularly poorly in mathematics. A high proportion of VLBW adolescents (15%-20%), and an even higher proportion of ELBW adolescents (30%-50%), are receiving remedial assistance and/or have failed a grade. There are conflicting reports on whether the behavioural problems increase or improve with age, but most studies show that at adolescence the problems are still significantly greater in the VLBW cohort than in their peers. Methodologically rigorous studies of the current survivors to school-age should be conducted to determine whether the technological innovations in the 1990s have contributed to a reduction in psychoeducational and behavioural difficulties. Future research should also be directed towards early identification of school difficulties and development of intervention strategies targeted to the most vulnerable infants.

Increased risk of learning disabilities in low birth weight boys at age 11 years

BACKGROUND

Few studies have examined learning disabilities among low birth weight (< or =2500 g) children, and those that have, have focused on very low birth weight children (<1500 g). We tested the hypothesis that low birth weight increases the risk of reading and math disabilities, examined possible sex differences in the effect of low birth weight, and assessed risk across the entire range of low birth weight.

METHODS

Low birth weight and normal birth weight children were randomly selected from the 1983-1985 newborn lists of an urban and a suburban hospital in southeast Michigan. Children with neurological impairments were excluded. Children were evaluated at age 6 years and at age 11 years. Of the 823 children in the initial assessment, 717 (87.1%) participated in the second assessment. The Wechsler Intelligence Scale for Children--Revised and the Woodcock-Johnson Psycho-Educational Battery--Revised were used to identify children with learning disabilities. Learning disabilities were estimated in 574 children with IQs of > or =85.

RESULTS

Low birth weight was associated with increased risk for reading and math disability in male children (odds ratio = 3.3 and odds ratio = 6.5, respectively) but not in female children. The increased risk of learning disabilities among male children applied to the entire range of low birth weight and was observed in both the urban and suburban communities.

CONCLUSIONS

The effect of low birth weight on learning disabilities appears to be specific to male children. Although this sex-specific effect is consistent with previous findings of a greater vulnerability of male children to pregnancy and birth complications, it remains to be replicated and clarified.