Extremely low-birth-weight children and their peers. A comparison of school-age outcomes

Antenatal magnesium sulfate for fetal neuroprotection: a critical appraisal and systematic review of clinical practice guidelines

Background Magnesium sulfate is an accepted intervention for fetal neuroprotection. There are some perceived differences in the international recommendations on the use magnesium sulfate for fetal neuroprotection in preterm labor. Content This systematic review analyses the available clinical guidelines for the use of magnesium sulfate for fetal neuroprotection and compares the recommendations, and assesses the quality of guidelines. This provides the consensus, differences and explores the areas for future collaborative research. We searched databases of PUBMED, EMBASE, COCHRANE, Web of Science, LILACS; and included the national and the international clinical practice guidelines. We included seven guidelines out of 227 search results. We evaluated the methodological quality of guidelines using the Appraisal of Guidelines Research and Evaluation (AGREE II) tool and systematically extracted guideline characters, recommendation and supporting evidence base. Summary Five guidelines were of high quality and two were of moderate quality. One guideline achieved more than an 80% score in all the domains of AGREE II tool. All guidelines recommend use of magnesium sulfate for fetal neuroprotection. However, there are differences in other recommendations such as upper gestational age, dose, duration, repeating treatment and use of additional tocolytics. Outlook Future guidelines should include recommendations on all aspects of magnesium sulfate therapy for fetal neuroprotection. Future research and international collaboration should focus on areas where there are no international consensual recommendations.

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.

The Relationship Between Motor Delays and Language Development in Very Low Birthweight Premature Children at 18 Months Corrected Age

PURPOSE

The aim of this study is to determine if there is a specific association between motor delays and receptive and expressive language function, respectively, in prematurely born children.

METHOD

Retrospective data review: 126 premature children ≤ 1,250-g birthweight from English-speaking families were evaluated on motor development (normal, mild delay, and moderate-severe delay) and the cognitive and language scales of the Bayley Scales of Infant and Toddler Development-Third Edition (Bayley, 2006) at 18 months corrected age. Cognitive scores were categorized as normal, suspect, and abnormal. Gender, demographic, and perinatal variables were recorded and analyzed with respect to motor category.

RESULTS

Lower birthweight, chronic need for oxygen, severe intraventricular hemorrhage, and intestinal infection/inflammation were related to poorer motor development. On receptive language, the normal motor group attained significantly higher scores than the moderate-severe motor group but did not differ significantly from the mild delay motor group. On expressive language, the normal motor group had significantly higher scores than both the mild and moderate-severe groups. Girls performed better than boys on receptive and expressive language, but there was no significant interaction between gender and motor category on any of the Bayley scores. Cognitive, but not motor, category significantly contributed to variance of receptive language scores; cognitive and motor category each independently contributed to the variance in expressive language.

CONCLUSION

Findings suggest that motor control areas of the brain may be implicated in expressive language development of premature children. Further research is needed to determine the underlying factors for the association between motor and expressive language function.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Prevalence and neonatal factors associated with autism spectrum disorders in preterm infants

OBJECTIVES

To determine the prevalence of autism spectrum disorders (ASD) across gestational age, examine the risk of ASD by gestational age controlling for other risk factors, and identify potential risk factors in the neonatal intensive care unit.

STUDY DESIGN

A retrospective cohort of infants born at ≥ 24 weeks between January 1, 2000, and December 31, 2007 at 11 Kaiser Permanente Northern California hospitals (n = 195,021). ASD cases were defined by a diagnosis made at a Kaiser Permanente ASD evaluation center, by a clinical specialist, or by a pediatrician. Cox proportional hazards regression models were used to evaluate the association between gestational age and ASD as well as potential risk factors in the neonatal intensive care unit and ASD.

RESULTS

The prevalence of ASD in infants <37 weeks was 1.78% compared with 1.22% in infants born ≥ 37 weeks (P < .001). Compared with term infants, infants born at 24-26 weeks had an adjusted hazard ratio (HR) for a diagnosis of ASD of 2.7 (95% CI 1.5-5.0). Infants born at 27-33 weeks (adjusted HR 1.4, 95% CI 1.1-1.8) and 34-36 weeks (adjusted HR 1.3, 95% CI 1.1-1.4) were also at increased risk. High frequency ventilation and intracranial hemorrhage were associated with ASD in infants < 34 weeks.

CONCLUSIONS

ASD was ~ 3 times more prevalent in infants <27 weeks compared with term infants. Each week of shorter gestation was associated with an increased risk of ASD. High frequency ventilation and intracranial hemorrhage were associated with ASD among infants <34 weeks.

Spectrum of short- and long-term brain pathology and long-term behavioral deficits in male repeated hypoxic rats closely resembling human extreme prematurity

Brain injury in the premature infant is associated with a high risk of neurodevelopmental disability. Previous small-animal models of brain injury attributable to extreme prematurity typically fail to generate a spectrum of pathology and behavior that closely resembles that observed in humans, although they provide initial answers to numerous cellular, molecular, and therapeutic questions. We tested the hypothesis that exposure of rats to repeated hypoxia from postnatal day 1 (P1) to P3 models the characteristic white matter neuropathological injury, gray matter volume loss, and memory deficits seen in children born extremely prematurely. Male Sprague Dawley rats were exposed to repeated hypoxia or repeated normoxia from P1 to P3. The absolute number of pre-oligodendrocytes and mature oligodendrocytes, the surface area and g-ratio of myelin, the absolute volume of cerebral white and gray matter, and the absolute number of cerebral neurons were quantified stereologically. Spatial memory was investigated on a radial arm maze. Rats exposed to repeated hypoxia had a significant loss of (1) pre-oligodendrocytes at P4, (2) cerebral white matter volume and myelin at P14, (3) cerebral cortical and striatal gray matter volume without neuronal loss at P14, and (4) cerebral myelin and memory deficits in adulthood. Decreased myelin was correlated with increased attention deficit hyperactivity disorder-like hyperactivity. This new small-animal model of extreme prematurity generates a spectrum of short- and long-term pathology and behavior that closely resembles that observed in humans. This new rat model provides a clinically relevant tool to investigate numerous cellular, molecular, and therapeutic questions on brain injury attributable to extreme prematurity.

Oligodendroglial alterations and the role of microglia in white matter injury: relevance to schizophrenia

Schizophrenia is a chronic and debilitating mental illness characterized by a broad range of abnormal behaviors, including delusions and hallucinations, impaired cognitive function, as well as mood disturbances and social withdrawal. Due to the heterogeneous nature of the disease, the causes of schizophrenia are very complex; its etiology is believed to involve multiple brain regions and the connections between them, and includes alterations in both gray and white matter regions. The onset of symptoms varies with age and severity, and there is some debate over a degenerative or developmental etiology. Longitudinal magnetic resonance imaging studies have detected progressive gray matter loss in the first years of disease, suggesting neurodegeneration; but there is also increasing recognition of a temporal association between clinical complications at birth and disease onset that supports a neurodevelopmental origin. Presently, neuronal abnormalities in schizophrenia are better understood than alterations in myelin-producing cells of the brain, the oligodendrocytes, which are the predominant constituents of white matter structures. Proper white matter development and its structural integrity critically impacts brain connectivity, which affects sensorimotor coordination and cognitive ability. Evidence of defective white matter growth and compromised white matter integrity has been found in individuals at high risk of psychosis, and decreased numbers of mature oligodendrocytes are detected in schizophrenia patients. Inflammatory markers, including proinflammatory cytokines and chemokines, are also associated with psychosis. A relationship between risk of psychosis, white matter defects and prenatal inflammation is being established. Animal models of perinatal brain injury are successful in producing white matter damage in the brain, typified by hypomyelination and/or dysmyelination, impaired motor coordination and prepulse inhibition of the acoustic startle reflex, recapitulating structural and functional characteristics observed in schizophrenia. In addition, elevated expression of inflammation-related genes in brain tissue and increased production of cytokines by blood cells from patients with schizophrenia indicate immunological dysfunction and abnormal inflammatory responses, which are also important underlying features in experimental models. Microglia, resident immune defenders of the central nervous system, play important roles in the development and protection of neural cells, but can contribute to injury under pathological conditions. This article discusses oligodendroglial changes in schizophrenia and focuses on microglial activity in the context of the disease, in neonatal brain injury and in various experimental models of white matter damage. These include disorders associated with premature birth, and animal models of perinatal bacterial and viral infection, oxygen deprivation (hypoxia) and excess (hyperoxia), and elevated systemic proinflammatory cytokine levels. We briefly review the effects of treatment with antipsychotic and anti-inflammatory agents in models of perinatal brain injury, and comment on the therapeutic potential of these strategies. By understanding the neurobiological basis of oligodendroglial abnormalities in schizophrenia, it is hoped that patients will benefit from the availability of targeted and more efficacious treatment options.

[Autism and prematurity: state of the art]

Research has shown a high rate of autism spectrum disorders among very low birth weight children over the past decade. This paper proposes a literature review on this topic. Two generations of research have followed one another. The first retrospective studies found a high rate of ASD among premature babies. The second generation of prospective studies underlined and relativized this risk. Prospective research using screening tools (M-CHAT) have found around 20 % ASD, whereas 2 studies assessing the actual diagnosis found 5 % and 8 % ASD, 10 to 12 times more than in the general population. A number of hypotheses have been put forward to explain these high rates of ASD: sensory impairment associated with prematurity, white matter abnormalities, and cerebellar impairment. The authors propose complex models that take into account neurological deficits and the effects of perinatal events on interactive dynamics between infants and their caregivers. These models aim to allow suitable prevention and care for premature children with autism, a heavy additional handicap.

Language functions in preterm-born children: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Preterm-born children (<37 weeks' gestation) have higher rates of language function problems compared with term-born children. It is unknown whether these problems decrease, deteriorate, or remain stable over time. The goal of this research was to determine the developmental course of language functions in preterm-born children from 3 to 12 years of age.

METHODS

Computerized databases Embase, PubMed, Web of Knowledge, and PsycInfo were searched for studies published between January 1995 and March 2011 reporting language functions in preterm-born children. Outcome measures were simple language function assessed by using the Peabody Picture Vocabulary Test and complex language function assessed by using the Clinical Evaluation of Language Fundamentals. Pooled effect sizes (in terms of Cohen's d) and 95% confidence intervals (CI) for simple and complex language functions were calculated by using random-effects models. Meta-regression was conducted with mean difference of effect size as the outcome variable and assessment age as the explanatory variable.

RESULTS

Preterm-born children scored significantly lower compared with term-born children on simple (d = -0.45 [95% CI: -0.59 to -0.30]; P < .001) and on complex (d = -0.62 [95% CI: -0.82 to -0.43]; P < .001) language function tests, even in the absence of major disabilities and independent of social economic status. For complex language function (but not for simple language function), group differences between preterm- and term-born children increased significantly from 3 to 12 years of age (slope = -0.05; P = .03).

CONCLUSIONS

While growing up, preterm-born children have increasing difficulties with complex language function.

Visual perception and visual-motor integration in very preterm and/or very low birth weight children: a meta-analysis

A range of neurobehavioral impairments, including impaired visual perception and visual-motor integration, are found in very preterm born children, but reported findings show great variability. We aimed to aggregate the existing literature using meta-analysis, in order to provide robust estimates of the effect of very preterm birth on visual perceptive and visual-motor integration abilities. Very preterm born children showed deficits in visual-spatial abilities (medium to large effect sizes) but not in visual closure perception. Tests reporting broad visual perceptive indices showed inconclusive results. In addition, impaired visual-motor integration was found (medium effect size), particularly in boys compared to girls. The observed visual-spatial and visual-motor integration deficits may arise from affected occipital-parietal-frontal neural circuitries.

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.

Risk factors affecting school readiness in premature infants with respiratory distress syndrome

OBJECTIVE

With advances in neonatal care, more children born prematurely are successfully reaching school age. It is unknown how many will be ready for school and what factors affect school readiness. Our objective was to assess readiness of children born prematurely for entry into public school, and determine risk factors associated with lack of school readiness in this population.

METHODS

This was a single-center prospective cohort study. Follow- up data were collected for 135 of 167 (81%) surviving premature infants with RDS requiring surfactant-replacement therapy. The children were seen between July 2005 and September 2006 (average age: 5.7 +/- 1.0 years) and underwent standardized neurodevelopmental and health assessments and socioeconomic status classification. A 4-level school-readiness score was constructed by using each child's standardized scores on assessments of basic concepts (Bracken School-Readiness Assessment), perceptual skills (Visual-Motor Integration Test), receptive vocabulary (Peabody Picture Vocabulary Test, Third Edition), daily living functional skills (Pediatric Functional Independence Measure), and presence of sensory impairments or autism. Proportional odds models were used to identify risk factors predicting lower school-readiness levels.

RESULTS

Mean birth weight was 1016 +/- 391 g, and mean gestational age was 27.5 +/- 2.6 weeks. Ninety-one (67%) children were school-ready. Using multivariate analysis, male gender, chronic lung disease, and severe intraventricular hemorrhage or periventricular leukomalacia were associated with lower school-readiness levels. However, the most powerful factor determining school-readiness level was low socioeconomic status.

CONCLUSION

Interventions targeting neonatal morbidities may be much less effective at improving overall performance at school age compared with the effect of the impoverished social environment.

Neurodevelopmental outcome of the premature infant

Advances in antenatal medicine and neonatal intensive care have successfully resulted in improved survival rates of preterm infants. These improvements have been most dramatic in infants born extremely low birth weight (ELBW, <or=1000 g) and at the limits of viability (22 to 25 weeks). But improvements in survival have not been accompanied by proportional reductions in the incidence of disability in this population. Thus, survival is not an adequate measure of success in these infants who remain at high risk for neurodevelopmental and behavioral morbidities. There is now increasing evidence of sustained adverse outcomes into school age and adolescence, not only for ELBW infants but for infants born late preterm.

Stability of neuromotor outcomes at 18 and 30 months of age after extremely low birth weight status

BACKGROUND

Extremely low birth weight (< or =1000 g) children have increased rates of cerebral palsy and other abnormal neurologic findings.

OBJECTIVE

To investigate the stability of neuromotor findings between 18 and 30 months' adjusted age in extremely low birth weight infants. METHODS. Seven hundred nineteen extremely low birth weight infants with assessments at 18 and 30 months' adjusted age were included in this analysis. At each visit a neurologic examination, the modified gross motor function classification system, and the Bayley Scales of Infant Development II were administered. Logistic regression models were constructed to assess neonatal factors and neuromotor function at 18 months of age associated with stability in neuromotor function.

RESULTS

Eighty-four percent of the children had agreement in neurologic/motor function at both visits. However, classification changed from normal to abnormal in 6% and from abnormal to normal in 10%. Diagnosis of cerebral palsy was consistent for 91% of the children, and the gross motor function classification system score was consistent for 83%. In multivariate models, factors associated with decreased severity or absence of cerebral palsy diagnosis at 30 months of age were higher gestational age, no periventricular leukomalacia or severe intraventricular hemorrhage, and a gross motor function classification system score of 0 (normal) at the 18-month visit, whereas factors associated with a new cerebral palsy diagnosis at 30 months of age were postnatal steroid use, periventricular leukomalacia or severe intraventricular hemorrhage, a gross motor function classification system score of > or =1 at 18 months of age, and asymmetrical limb movement at 18 months of age.

CONCLUSIONS

Stability of neurologic diagnosis in 84% and cerebral palsy in 91% of the children is reassuring. However, for a significant percentage of children, the neurologic diagnosis changes between 18 and 30 months of age. The diagnosis of cerebral palsy may be delayed in some infants until an older adjusted age.

Positive screening on the Modified Checklist for Autism in Toddlers (M-CHAT) in extremely low gestational age newborns

OBJECTIVE

To test the hypothesis that children born preterm are more likely to screen positive on the M-CHAT for an autism spectrum disorder.

STUDY DESIGN

We compared the M-CHAT positive rate of those with cerebral palsy, cognitive impairment, and vision and hearing impairments to those without such deficits.

RESULTS

Relative to children who could walk, the odds for screening positive on the M-CHAT were increased 23-fold for those unable to sit or stand independently and more than 7-fold for those requiring assistance to walk. Compared with children without a diagnosis of cerebral palsy, those with quadriparesis were 13 times more likely to screen positive, and those with hemiparesis were 4 times more likely to screen positive. Children with major vision or hearing impairments were 8 times more likely to screen positive than those without such impairments. Relative to those with a Mental Development Index (MDI) of >70, the odds for screening positive were increased 13-fold for those with an MDI of <55 and more than 4-fold for those with an MDI of 55 to 69.

CONCLUSIONS

Major motor, cognitive, visual, and hearing impairments appear to account for more than half of the positive M-CHAT screens in extremely low gestational age newborns. Even after those with such impairments were eliminated, 10% of children--nearly double the expected rate--screened positive.

Community supports after surviving extremely low-birth-weight, extremely preterm birth: special outpatient services in early childhood

OBJECTIVE

To determine special outpatient services (SOS) use, need, associated factors, and neurodevelopmental and functional outcomes among extremely preterm infants at 18 to 22 months' corrected age.

DESIGN

Retrospective analysis.

SETTING

National Institute of Child Health and Human Development (NICHD) Neonatal Research Network.

PARTICIPANTS

Infants younger than 28 weeks' gestational age who had been born weighing less than 1000 g at an NICHD Neonatal Research Network center from January 1, 1997, to December 31, 2000, and who were receiving follow-up at 18 to 22 months' corrected age.

INTERVENTIONS

Questionnaires were administered at the 18- to 22-month follow-up visit regarding SOS use since hospital discharge and the current need for SOS (social work, visiting nurse, medical specialty, early intervention, speech and language services, occupational therapy and physical therapy, and neurodevelopmental and behavioral services).

MAIN OUTCOME MEASURES

The use of and need for SOS were analyzed by gestational age. Logistic regression analysis identified factors independently associated with the use of more than 5 services and with the need for any services.

RESULTS

Of 2315 infants, 54.7% used more than 3 SOS by 18 to 22 months, and 19.1% used 6 to 7 SOS. The need for any SOS was reported by approximately 37%. The following variables that were commonly associated with adverse neurodevelopmental outcomes were also associated with the use of more than 5 SOS: sepsis, birth weight, postnatal corticosteroid use, bronchopulmonary dysplasia, and cystic periventricular leukomalacia or grade 3 or 4 intraventricular hemorrhage. Male sex was associated with the need for any SOS. Although high SOS use was more likely among children with adverse neurodevelopmental outcomes, a reported need for SOS was common even among those with mild developmental impairment (39.7%) and mild cerebral palsy (42.2%).

CONCLUSIONS

High SOS use is common, has identifiable neonatal risk factors, and is associated with neurodevelopmental impairment. Extremely preterm survivors have substantial need for community supports regardless of their impairment level. Efforts to improve comprehensive delivery of family-centered community-based services are urgently needed.

Communication and Academic Challenges in Early Adolescence for Children Who Have Been Adopted From the Former Soviet Union

Purpose

This was a Time II survey of outcomes for children, now ages 9 to 13 years, who were almost 4 years old on average when they were adopted from the former Soviet Union.

Method

As part of a larger study (see T. McGuinness, R. Ryan, & C. Broadus Robinson, 2005), parents of 55 children ( M age = 11 years) were surveyed regarding their children’s speech-language, behavior, and eligibility for special education. The children’s mean length of institutionalization was 36 months.

Results

A total of 45, or 82%, of the children had at least one special education label. The most frequent was communication disorder, which was reported for 34 children, or 62%. The frequency of attention deficit hyperactivity disorder (ADHD) was high, 42%. The ratio of boys to girls for communication disorders and ADHD was 1.5:1. Girls who were adopted after 36 months of age were 4 times more likely than girls who were adopted before 36 months to be labeled ADHD, and children with low birth weight exhibited learning disabilities twice as often as children with normal birth weight.

Conclusion

Speech-language, learning, and attention deficits for late-adopted, early adolescent children were higher than expected. These children from the former Soviet Union experienced substantial preadoption adversity associated with lengthy orphanage stays and poor care. Gender and low birth weight were also factors.

Behaviour difficulties and cognitive function in children born very prematurely

Children born very prematurely are at risk of low average IQ and behaviour difficulties throughout childhood and adolescence. Associations among preterm birth, IQ and behaviour have been reported; however, the nature of the relationship among these outcomes is not fully understood. Some studies have proposed that the consequences of preterm birth, such as low average IQ, mediate the association between preterm birth and later behaviour difficulties. The aim of this study was to investigate the relationship among preterm birth, IQ and childhood behaviour problems, by testing mediation and moderation models. We assessed a UK sample of 69 very preterm (< 32 weeks gestational age) and 70 term born children aged between 6 and 12 years on an abbreviated IQ test. Parental behaviour ratings were obtained using the Strengths and Difficulties Questionnaire. Mediation and moderation models were tested using hierarchical regression analyses. The findings indicate that IQ mediates the relationship between birth status and emotional behaviour problems. Furthermore, the results indicate that birth status moderates the relationship between IQ and behavioural difficulties, i.e., that the relationship between low IQ and behaviour problems is most pronounced for the preterm children. The findings highlight the importance of considering indirect effects in the study of outcome after very preterm birth.

Children with learning disabilities

Children with learning disabilities can present numerous challenges in the acute hospital setting. This review article examines the causes and presentations of learning disability, and considers some of the management strategies employed when these children present for surgery.

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.

The effect of pre-employment factors on job control, job strain and psychological distress: a 31-year longitudinal study

This study examined the role of pre-employment factors, such as maternal antenatal depression, low birth weight, childhood socioeconomic position, early adolescence health risk behaviours and academic performance, in the relationship between work characteristics (low job control and high job demands, or job strain) and psychological distress at age 31. The data of 2062 women and 2231 men was derived from the prospective unselected population-based Northern Finland 1966 Birth Cohort study. Results of linear regression models showed that being female, father's low socioeconomic position, and poor academic achievement in adolescence were linked to low control and high job strain jobs at age 31, and that low control and high job strain were associated with psychological distress at age 31. Although having lower school grades, high absence rate from school, and moderate alcohol consumption at age 14 were significant predictors of psychological distress at age 31, the associations between job control, job strain and psychological distress remained after controlling for these and other pre-employment effects. As such, pre-employment factors do seem to link people to risky work environments, which in turn seem to relate strongly to psychological distress. However, the relationship between pre-employment factors and later psychological distress in adulthood is not completely explained by job environment.

ADHD-like hyperactivity, with no attention deficit, in adult rats after repeated hypoxia during the equivalent of extreme prematurity

The most common behavioural disorder seen in children and adolescents born extremely prematurely is attention deficit hyperactivity disorder (ADHD). The hyperactive/impulsive sub-type of ADHD or the inattentive sub-type or the hyperactive/impulsive/inattentive sub-type can be evident. These sub-types of ADHD can persist into adulthood. The aim of this study was to investigate the relevance of a new immature rat model of repeated hypoxic exposure to these behavioural characteristics of extreme prematurity. More specifically, this study aimed to measure ADHD-like hyperactivity in response to delayed reward, and inattention, in repeated hypoxic versus repeated normoxic rats. Sprague-Dawley rats were exposed to either repeated hypoxia or repeated normoxia during postnatal days (PN) 1-3. The rat brain during PN1-3 is generally considered to be developmentally equivalent to the human brain during extreme prematurity. The rats were then behaviourally tested at 16 months-of-age on a multiple component fixed interval-extinction test. This test detects ADHD-like hyperactivity in response to delayed reward, as well as inattention. It was found that the repeated hypoxic rats exhibited ADHD-like hyperactivity in response to delayed reward, but no attention deficit, when compared to repeated normoxic rats. These findings provide a new animal model to investigate the biological mechanisms and treatment of ADHD-like hyperactivity due to repeated hypoxia during the equivalent of extreme prematurity.

Intellectual development in a Danish cohort of prematurely born preschool children: specific or general difficulties?

A national cohort of extremely low birth weight (ELBW) and/or extremely preterm (EPT) children and a term control group was followed up at the age of 5 years. The primary objective was to investigate whether premature birth had a global impact on cognitive functions or affected specific functions only. Assessment tools were Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), Movement Assessment Battery for Children (M-ABC), and subtests from the Neuropsychological Assessment 4-7 years (NEPSY). The mean Full Scale IQ (FSIQ) and M-ABC score of the index children were 1.1 and 1.2 SDs lower than that of the control children (p <.001). Most WPPSI-R subtests showed medium to large differences between index and control children, suggesting a global impact of premature birth on cognitive functions. For both unadjusted and FSIQ adjusted means, no significant group differences on tests of memory or executive function were observed (p >.1), suggesting little impact of premature birth on these specific functions. In this sample, cognitive difficulties in 5-year-old ELBW and/or EPT children tended to be associated with general intellectual difficulties rather than with specific dysfunctions; however, the implications of this finding are ambiguous due to substantial attrition on the NEPSY subtests.

Physical outcome and school performance of very-low-birthweight infants treated with minimal handling and early nasal CPAP

AIM

To describe physical outcome and school performance in a cohort of very-low-birthweight infants treated with early nasal continuous positive airway pressure (NCPAP)/minimal handling regimen with permissive hypercapnia, in comparison to siblings of normal birthweight.

MATERIAL AND METHODS

Neonatal and follow-up data from 213 very-low-birthweight infants from 1983-1988 were registered and a questionnaire concerning school achievements was sent to the families of survivors and siblings attending school.

RESULTS

Mortality was 22%. Of the survivors, 4% had moderate-severe and 9% mild sequelae. Eighty-seven per cent of VLBW children and 95% of their siblings attended regular school. Average or above-average achievement was accomplished by 33 (65%) of the VLBW children and 34 (74%) of the siblings in mathematics, and 35 (69%) and 32 (68%), respectively, in reading/spelling. None of these differences reached statistical significance. However, the performance ratings correlated significantly with socio-economic conditions.

CONCLUSION

In this study of infants treated with a regimen of early NCPAP/minimal handling, we found a relatively low incidence of handicaps and impairments. Nearly 90% attended ordinary schools, with near-average performances in mathematics and reading/spelling, which were not statistically different to their siblings. The overall results indicate that these infants fare at least as well as survivors after conventional treatment.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Ensuring accurate knowledge of prematurity outcomes for prenatal counseling

OBJECTIVES

To determine the accuracy of knowledge of different health care providers regarding survival and long-term morbidity rates for very premature infants and to examine whether a focused educational intervention improves the accuracy of this knowledge and influences health care decisions.

METHODS

Using hypothetical case scenarios with infants at < or =28 weeks of gestation, we surveyed a variety of caregivers involved in perinatal communication and decision-making processes at a tertiary center that provides intensive care for neonates. We asked physicians from the pediatrics and obstetrics services and nurses and nurse practitioners from the NICU and obstetrics ward for their best estimates of survival and major long-term disability rates and for their opinions regarding the appropriateness of resuscitation and life support at each week of gestation of <29 weeks. After the survey, we educated all providers about current data on survival and long-term disability rates for preterm infants and gave them pocket-sized cards summarizing this information for reference during prenatal counseling. One month after the educational intervention and complete dissemination of the cards, a questionnaire with questions identical to those in the first survey was mailed to the same individuals.

RESULTS

Fifty-one health care providers were involved in the baseline survey. The response rates for the postintervention survey were 100% for physicians (20 of 20 subjects) and nurses (20 of 20 subjects) and 91% (10 of 11 subjects) for the nurse practitioners. In the baseline survey, statistically significant underestimates of survival rates were seen for physicians and nurses at 23 to 28 weeks of gestation and for nurse practitioners at 23 to 27 weeks of gestation. Statistically significant overestimates of disability rates were seen for physicians and nurse practitioners at < or =26 weeks of gestation and for nurses at < or =28 weeks of gestation. After the intervention, respondents demonstrated significant improvements in the accuracy of survival and disability estimates at many, but not all, gestational ages. Although underestimation of survival rates and overestimation of disability rates decreased after the intervention, it persisted to some degree. After the intervention, a larger proportion of physicians (53% vs 21%) and a smaller proportion of nurses (10% vs 37%) were likely to recommend resuscitation for infants born at 23 weeks of gestation.

CONCLUSIONS

Physicians, nurses, and nurse practitioners underestimated survival rates and overestimated long-term disability rates for very premature infants. After education, their estimates of survival and long-term disability rates for these infants improved significantly. More accurate estimates of survival and disability rates affected physicians' and nurses' theoretical decision-making regarding the appropriateness of resuscitation at 23 weeks of gestation.

Current concepts in intrauterine growth restriction

Regulation of fetal growth is multifactorial and complex. Diverse factors, including intrinsic fetal conditions as well as maternal and environmental factors, can lead to intrauterine growth restriction (IUGR). The interaction of these factors governs the partitioning of nutrients and rate of fetal cellular proliferation and maturation. Although IUGR is probably a physiologic adaptive response to various stimuli, it is associated with distinct short- and long-term morbidities. Immediate morbidities include those associated with prematurity and inadequate nutrient reserve, while childhood morbidities relate to impaired maturation and disrupted organ development. Potential long-term effects of IUGR are debated and explained by the fetal programming hypothesis. In formulating a comprehensive approach to the management and follow-up of the growth-restricted fetus and infant, physicians should take into consideration the etiology, timing, and severity of IUGR. In addition, they should be cognizant of the immediate perinatal response of the growth-restricted infant as well as the childhood and long-term associated morbidities. A multi disciplinary approach is imperative, including early recognition and obstetrical management of IUGR, assessment of the growth-restricted newborn in the delivery room, possible monitoring in the neonatal intensive care unit, and appropriate pediatric follow-up. Future research is necessary to establish effective preventive, diagnostic, and therapeutic strategies for IUGR, perhaps affecting the health of future generations.

Les troubles du développement des enfants grands prématurés mesurés à l’âge scolaire

Advances in perinatal care have lead to the survival of an increasing number of children born very premature. The purpose of this review is to discuss findings in the literature regarding long term developmental outcome of infants born prematurely especially for studies with children at least 5 years old, born in the 80's or after, in a context of care with increased use of antenatal corticoids, in utero transfer, and surfactant therapy. Developmental sequelae, which are seen in children older than those presenting severe deficiencies, concerns a greater number of very premature children. They have poorer outcomes than term children or normal birth weight controls for cognitive-neuropsychological skills, school performances and behavior. Long term follow up of these children shows that consequences are still present for adolescents or young adults. There is a gradient of developmental sequelae in children that is inversely related to decreasing gestational age or birth weight. Developmental sequelae are related to neonatal medical complications and social risks factors. Research should be conducted in order to better understand etiology and neuropathological basis of sequelae, and the long term developmental implication of being born very premature and the type of care or intervention which could improve their development. An early and regular follow up by a team specialized in child development should be proposed in order to detect developmental sequelae and propose early intervention.

Psychiatric symptoms and disorders in adolescents with low birth weight

OBJECTIVE

To evaluate the prevalence of psychiatric symptoms and disorders associated with low birth weight.Design/study groups: A population based follow up study of 56 very low birthweight (VLBW: birth weight < or = 1500 g), 60 term small for gestational age (SGA: birth weight < 10th centile), and 83 term control (birth weight > or = 10th centile) children at 14 years of age.

OUTCOME MEASURES

Schedule for affective disorders and schizophrenia for school aged children, attention deficit/hyperactivity disorder (ADHD) rating scale IV, autism spectrum screening questionnaire, and children's global assessment scale.

RESULTS

VLBW adolescents had a higher prevalence of psychiatric symptoms (46%) than controls (13%) (odds ratio (OR) 5.7, 95% confidence interval (CI) 2.5 to 13.0) and more psychiatric disorders (25%) than controls (7%) (OR 4.3, 95%CI 1.5 to 12.0), especially anxiety disorders. Although 25% of the VLBW adolescents had attention problems, ADHD was diagnosed in only 7%. Four VLBW adolescents had symptoms of Asperger's disorder, and the VLBW group had a higher sum score than controls on the autism spectrum screening questionnaire. Although more SGA adolescents had psychiatric symptoms than controls (23% v 13%), the difference was not statistically significant. Results remained essentially the same when adolescents with low estimated intelligence quotient were excluded, and persisted after possible psychosocial confounders had been controlled for.

CONCLUSION

VLBW, but not SGA adolescents, have a high risk of developing psychiatric symptoms and disorders by the age of 14, especially attention deficit, anxiety symptoms, and relational problems.

Preschool outcome of less than 801-gram preterm infants compared with full-term siblings

OBJECTIVE

Extremely low birth weight (ELBW) infants are at greater risk for neurodevelopmental delay than full-term infants. Outcomes may be compromised secondary to abnormal brain development associated with complications of prematurity. Long-term cognitive outcome has also been reported to be significantly influenced by postnatal factors. The objective of this study was to clarify the effects of prematurity separate from environmental factors on growth and neurodevelopmental outcomes by comparing ELBW children with their full-term siblings.

METHODS

The study consisted of 25 ELBW children, a subset selected from a larger population of infants who were <801 g birth weight and enrolled in a longitudinal follow-up project from birth and their 25 full-term, full-weight siblings. Twenty-three sets of siblings were evaluated at 5 years of age and 2 sets at 3 years of age with standardized medical, social, cognitive, motor, and language testing. Physical and neurodevelopmental outcomes were compared between groups, controlling for gender and socioeconomic status (SES).

RESULTS

At follow-up, ELBW children were lighter, were shorter, and had smaller head circumference. The ELBW children had lower Stanford-Binet IQs (85 +/- 12 [mean +/- SD] and 95 +/- 11), with lower Stanford-Binet subtests except short-term memory and quantitative reasoning, lower spelling scores on the Wide Range Achievement Test, and lower Peabody motor quotients (79 +/- 11 and 92 +/- 17). Preschool Language Scale quotients were not different, but other receptive language measures were lower for ELBW children. High SES seemed to modify the impact of preterm status on cognitive and language but not motor scores. The mean IQ for high-SES ELBW children was equivalent to that of the low-SES term siblings.

CONCLUSIONS

Preschool-age cognitive and language functioning in ELBW children seemed to be affected by both prenatal and birth influences (preterm status) and postnatal influences (SES variables). Motor scores were significantly related to preterm status but not to SES.

Educational and social competencies at 8 years in children with threshold retinopathy of prematurity in the CRYO-ROP multicenter study

OBJECTIVE

To describe the educational status and special education services at 8 years among children who had threshold retinopathy of prematurity (ROP).

METHODS

A prospective study was conducted of a cohort of children who had birth weight of <1251 g and threshold ROP in the Cryotherapy for Retinopathy of Prematurity multicenter study. At age 5.5 years, visual status, functional skills, and social information were obtained. At 8 years, special education classes, developmental disabilities, rehabilitation therapies, and academic and social competencies were determined by questionnaire. Visual status was considered favorable/unfavorable on the basis of the better eye.

RESULTS

Of 255 survivors, 216 (85%) were evaluated at both 5.5 and 8 years. Major impairments were significantly more prevalent in children with unfavorable versus favorable visual status: cerebral palsy (39% vs 16%), developmental disability (57% vs 22%), autism (9% vs 1%), and epilepsy (23% vs 3%). Special education services (63% vs 27%), below-grade-level academic performance (84% vs 48%), and school-based rehabilitation services were significantly less common in children with favorable visual status. Favorable visual status, favorable functional ratings at 5.5 years, markers of higher socioeconomic status, and nonblack race were associated with significantly lower rates of both special education placement and below-grade-level academic performance at age 8. On multivariate logistic regression, only favorable visual status and functional status remained significant predictors for decreasing special education placement.

CONCLUSION

Threshold ROP is associated with high rates of developmental, educational, and social challenges in middle childhood; preserved vision was associated with a clear advantage, with more than half of the children with favorable visual status performing at grade level.

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.

Continuing care of NICU graduates

After a prolonged and complicated hospital stay, the NICU graduate enters the world with unique and complex medical problems. A well-coordinated multidisciplinary approach is essential in the follow-up care of these infants. The crucial issues for the pediatrician who cares for these infants are assisting in the catch-up growth and the ongoing healing process with good nutritional supplementation, while preventing further problems by detecting and treating illness early. Timely inclusion of other appropriate health care personnel and facilities in the care may be crucial and rewarding. The role of the pediatrician in helping these infants attain their full physical, neurodevelopmental, emotional, and psychosocial potential by providing optimal care is invaluable. With appropriate support most NICU graduates will become productive and well-adjusted adults. The pediatrician plays a major role in completing this process and contributes to the eventual success of the neonatal intensive care that these infants are subjected to at the very beginning of their lives.

Preterm outcomes research: a critical component of neonatal intensive care

While early preterm outcome studies described the lives of preterm survivors to justify the efforts required to save them, subsequent studies demonstrated their increased incidence of cerebral palsy, mental retardation, sensory impairments, minor neuromotor dysfunction, language delays, visual-perceptual disorders, learning disability and behavior problems compared to fullterm controls. Because infants born at the lower limit of viability require the most resources and have the highest incidence of neurodevelopmental disability, there is concern that resources have gone primarily to neonatal intensive care and are not available for meeting the followup, health, educational and emotional needs of these fragile infants and their families. Despite many methodological concerns, preterm outcome studies have provided insight into risk factors for and causes of CNS injury in preterm infants. Nevertheless, it remains difficult to predict neurodevelopmental outcome for individual preterm infants. Perinatal and neonatal risk factors are inadequate proxies for neurodevelopmental disability. Recent randomized controlled trials with one to five year neurodevelopmental followup have provided valuable information about perinatal and neonatal treatments. Recognizing adverse longterm neurodevelopmental effects of pharmacological doses of postnatal steroids is a sobering reminder of the need for longterm neurodevelopmental followup in all neonatal randomized controlled trials. Ongoing longterm preterm neurodevelopmental studies, analysis of changes in outcomes over time and among centers, and evaluation of the longterm safety, efficacy and effectiveness of many perinatal and neonatal management strategies and proposed neuroprotective agents are all necessary for further medical and technological advances in neonatal intensive care.

Macropremies: underprivileged newborns

The focus of neonatal intensive care has been on very low birthweight infants, who comprise only 1.4% of neonates. Too little attention is paid to moderately preterm infants that we call macropremies or moderately low birthweight infants (MLBW, with birthweights 1500-2500 grams). Admitting over half MLBW infants to normal nurseries presumes that they have few needs and an excellent prognosis similar to fullterm newborns. It does not take into account the macropremie's vulnerability to complications of prematurity due to immature organ systems. Obstetricians are increasingly willing to deliver these infants prematurely for signs of fetal distress. As many as 25% of children with cerebral palsy referred to a disability clinic in Paris were MLBW, with hypoxic-ischemic-inflammatory associated disorders in one-third. The majority of MLBW infants who required neonatal intensive care at a tertiary care center in Baltimore had complications of prematurity: 47% had respiratory problems, 20% had feeding intolerance and 9% had hypoglycemia. MLBW infants comprise 5-7% of the neonatal population but account for 14% of neonatal deaths, 18-37% of children with cerebral palsy and 7-12% of children with mental retardation. Increasing the level of neonatal care for the macropremie's transition to extrauterine life would be economically feasible if it prevented as few as 30% of cases of major disability. A change in attitude towards this low risk (but not risk free) group of MLBW infants will both reduce morbidity and improve their health and neurodevelopmental outcome. It includes: 1) Providing an intermediate level of neonatal care for a short duration, with close monitoring and prompt intervention as needed, and 2) Neonatal neurodevelopmental screening to allow focused neurodevelopmental followup of MLBW infants with abnormalities.

Cognitive and neuropsychological outcomes: more than IQ scores

Improved survival in preterm infants has broadened interest in cognitive and neuropsychological outcomes. The incidence of major disabilities (moderate/severe mental retardation, neurosensory disorders, epilepsy, cerebral palsy) has remained consistent, but high prevalence/low severity dysfunctions (learning disabilities, ADHD, borderline mental retardation, specific neuropsychological deficits, behavioral disorders) have increased. The follow-up literature contains methodologic problems that make generalizations regarding outcome difficult, and these are discussed. Although mean IQs of former VLBW infants generally are in the low average range and are 3-9 points below normal birth weight peers, these scores mask subtle deficits in: visual-motor and visual-perceptual abilities, complex language functions, academics (reading, mathematics, spelling and writing), and attentional skills. There is an increased incidence of non-verbal learning disabilities, need for special educational assistance, and behavioral disorders in children born prematurely. Males have more problems, and there is a trend for worsening outcome over time, due to emergence of more subtle deficits in response to increased performance demands. In addition to IQ and achievement testing in follow-up, there should be evaluation of executive functions and attention, language, sensorimotor functions, visuospatial processes, memory and learning, and behavioral adjustment.

Longitudinal, 15-year follow-up of children born at less than 29 weeks' gestation after introduction of surfactant therapy into a region: neurologic, cognitive, and educational outcomes

OBJECTIVE

To measure the primary and secondary school-age neurologic, cognitive, and educational outcomes in a cohort of extremely premature infants born after the introduction of exogenous surfactant therapy in a circumscribed region.

METHODS

Two hundred thirteen infants born at <29 weeks' gestation were cared for at a regional referral center during 1985-1987. At primary school age, neurologic and cognitive outcomes, educational achievement, school placement, health status, and socioeconomic status were determined by follow-up visit. At secondary school age, school placement and health status were evaluated by telephone interview.

RESULTS

One hundred thirty-two infants survived to school age, of whom 127 (96%) were evaluated in 1992-1995 and 126 (95%) were evaluated in 2000. Mean ages were 7.0 years at first follow-up and 14.1 years at second follow-up. At primary-school age follow-up, 19 children (15%) had cerebral palsy, 24 (19%) had a general cognitive index <70, and 41 (32%) were placed in a self-contained, special classroom. Thirty-nine children (31%) had no physical or educational impairment, whereas 27 (21%) had at least 1 severe disability. At secondary school age, cerebral palsy incidence remained unchanged, whereas 36 children (29%) were placed in a special classroom. Fifty-one children (41%) had no physical or educational impairment, whereas 24 (19%) had at least 1 severe disability. Neonatal intraventricular hemorrhage and low socioeconomic status were the strongest predictors of adverse outcomes.

CONCLUSIONS

Premature infants born in the surfactant era remain at high risk of neurodevelopmental compromise. Although many of these children do well, a significant minority will require intensive special educational services through secondary school age.

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.

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.

Comprehensive primary care follow-up for premature infants

Advances in perinatal and neonatal care have led to an increased incidence of survival of premature infants. Although most premature infants have normal outcomes, they are at increased risk for morbidity and mortality and require comprehensive primary care follow-up after they are discharged from the hospital. This article will review guidelines for general follow-up of premature infants and the associated problems related to prematurity. General follow-up is performed by the pediatric nurse practitioner, with subspecialty consultant referrals as needed. Knowledge of the problems of prematurity and treatment regimes will assist the pediatric nurse practitioner in providing high-quality care to these high-risk infants.

Biology versus environment in the extremely low-birth weight infant

This article examines the role of biologic and environmental factors in determining the long-term outcomes of extremely low-birth weight infants. Research focusing on follow-up to at least 4 years of age is reviewed. Methodologic issues related to sampling, the use of control groups, and diagnostic criteria are also discussed. The use of cumulative models of risk for examining the relative contribution of environmental and biologic factors is presented.

Neurodevelopmental and functional outcomes of extremely low birth weight infants in the National Institute of Child Health and Human Development Neonatal Research Network, 1993-1994

OBJECTIVES

The purposes of this study were to report the neurodevelopmental, neurosensory, and functional outcomes of 1151 extremely low birth weight (401-1000 g) survivors cared for in the 12 participating centers of the National Institute of Child Health and Human Development Neonatal Research Network, and to identify medical, social, and environmental factors associated with these outcomes.

STUDY DESIGN

A multicenter cohort study in which surviving extremely low birth weight infants born in 1993 and 1994 underwent neurodevelopmental, neurosensory, and functional assessment at 18 to 22 months' corrected age. Data regarding pregnancy and neonatal outcome were collected prospectively. Socioeconomic status and a detailed interim medical history were obtained at the time of the assessment. Logistic regression models were used to identify maternal and neonatal risk factors for poor neurodevelopmental outcome.

RESULTS

Of the 1480 infants alive at 18 months of age, 1151 (78%) were evaluated. Study characteristics included a mean birth weight of 796 +/- 135 g, mean gestation (best obstetric dates) 26 +/- 2 weeks, and 47% male. Birth weight distributions of infants included 15 infants at 401 to 500 g; 94 at 501 to 600 g; 208 at 601 to 700 g; 237 at 701 to 800 g; 290 at 801 to 900 g; and 307 at 901 to 1000 g. Twenty-five percent of the children had an abnormal neurologic examination, 37% had a Bayley II Mental Developmental Index <70, 29% had a Psychomotor Developmental Index <70, 9% had vision impairment, and 11% had hearing impairment. Neurologic, developmental, neurosensory, and functional morbidities increased with decreasing birth weight. Factors significantly associated with increased neurodevelopmental morbidity included chronic lung disease, grades 3 to 4 intraventricular hemorrhage/periventricular leukomalacia, steroids for chronic lung disease, necrotizing enterocolitis, and male gender. Factors significantly associated with decreased morbidity included increased birth weight, female gender, higher maternal education, and white race.

CONCLUSION

ELBW infants are at significant risk of neurologic abnormalities, developmental delays, and functional delays at 18 to 22 months' corrected age.

Developmental problems and interactions between mothers and prematurely born children

This study explored how the developmental status of 49 3-year-old prematurely born children related to the interactions between these children and their mothers. Two 2-hour observations of mother-child interactions, the Home Observation for Measurement of the Environment (HOME) inventory, a developmental assessment, and Nursing Child Assessment Teaching Scale (NCATS) were scored when the child was 3 years corrected age. The effects of specific developmental problems (cognitive, language, and attention) were examined by comparing subgroups with and without these problems. Children with normal IQs spent less time not playing and scored higher on the NCATS than children with low IQs. Mothers of children with normal IQs scored higher on provision of play materials on the HOME. The mothers of children with language concerns interacted less, talked less, were more negative, and scored lower on the HOME and NCATS than mothers of the children with normal language abilities. Children with attention problems were more active than children with normal attention spans. These findings suggest that mother-child interactions might be useful for identifying children at risk for developmental delay and that interventions with preschool children with developmental delays will probably be more effective if their mothers are helped to provide a more appropriate social environment.