Outcome at school age of children with birthweights of 1000 grams or less

The Impact of Low-risk Prematurity on Maternal Behaviour and Toddler Outcomes

This short-term longitudinal research project was designed to compare the maternal behaviour of mothers whose toddlers had been born preterm with the maternal behaviour of mothers whose toddlers had been born at term; the outcomes for the toddlers were also assessed. Twenty-one toddlers who had been born preterm with low medical risk (1460-2420 grams) were compared with 21 term toddlers who were matched in terms of social class. The heightened maternal responsiveness that had been observed during the first year with preterm infants had disappeared by 12 months, and by 20 months it was the mothers whose infants had been born at term who were more vocally responsive. During the second year, the mothers of preterm toddlers were characterised by more maternal control behaviour than were the mothers of term toddlers. Assessments of cognitive and language performance at the gestationally corrected ages of 12 and 20 months did not differentiate the toddlers who had been born preterm and term. In terms of play skills, reflected during interaction with their mothers at 12 and 20 months, the preterm toddlers were more actively involved than were the term toddlers. Despite the successful adjustment of these low-risk preterm toddlers, maternal behaviour was affected by the circumstances of preterm birth, even after 20 months.

Cortical neuronal loss after chronic prenatal hypoxia: a comparative laboratory study

Objective

The purpose of this study was to investigate the prenatal hypoxic effect on the fetal brain development.

Methods

We used the guinea pig chronic placental insufficiency model to investigate the effect of hypoxia on fetal brain development. We ligated unilateral uterine artery at 30-32 days of gestation (dg : with term defined as -67 dg). At 50 dg, 60 dg, fetuses were sacrificed and assigned to either the growth-restricted (GR) or control (no ligation) group. After fixation, dissection, and sectioning of cerebral tissue from these animals, immunohistochemistry was performed with NeuN antibody, which is a mature neuronal marker in the cerebral cortex.

Results

The number of NeuN-immunoreactive (IR) cells in the cerebral cortex did not differ between the GR and control groups at 50 dg. However, the number of NeuN-IR cells was lesser in GR fetuses than in controls at 60 dg (p<0.05).

Conclusion

These findings show that chronic prenatal hypoxia affect the number of neuron in the cerebral cortex of guinea pig fetus at 60 dg. The approach used in this study is helpful for extending our understanding of neurogenesis in the cerebral cortex, and the findings may be useful for elucidating the brain injury caused by prenatal hypoxia.

Psychopathology and adaptive functioning among extremely low birthweight children at eight years of age

The objective of this study was to explore the relationship among extremely low birthweight (ELBW), psychopathology, and impairments in adaptive functioning in a regional cohort of 7–8-year-old children with a birthweight of 501–1,000 g compared to a sample of full-term controls. One-hundred twenty-nine of 143 (90%) ELBW survivors and 145 controls, born between 1977 and 1981, agreed to participate in the study. The children were assessed at a mean, unadjusted age of 7.8 years. Results showed that parents of ELBW children were more likely than parents of controls to report specifically problems of attention-deficit hyperactivity disorder (ADHD). There were few differences between the groups in terms of impairments in adaptive functioning. Further analyses showed that the relationship between ELBW and ADHD could not be explained by confounding psychosocial risk factors, nor were ELBW children from disadvantaged environments more likely to have ADHD problems than ELBW children from nondisadvantaged environments. The relationships between ELBW and ADHD problems appeared to be associated with the lower IQ of the ELBW subjects.

Low birth weight, prematurity, and paternal social status: impact on the basic competence test in Taiwanese adolescents

OBJECTIVE

To investigate whether birth weight and paternal education may have independent and interactive effects on the learning achievement of adolescents.

STUDY DESIGN

We linked birth weights, gestational ages (term or preterm) and paternal education of a 4-year birth cohort to the Basic Competence Test (BCT) scores in Mandarin, mathematics and science for junior high school students age 15 to 16 years. The study groups comprised infants with term low birth weight (TLBW; n = 33 507), preterm normal birth weight (PNBW; n =19 905), and preterm low birth weight (PLBW; n = 25 840), as well as randomly selected term infants with normal birth weight (TNBW; n = 83 756). Paternal education levels were categorized.

RESULTS

Compared with the TNBW adolescents, the TLBW adolescents consistently showed larger deficits in mean scores for Mandarin (beta = -2.36), mathematics (beta = -2.89), and science (beta = -2.11). The corresponding significant deficit scores for the PLBW adolescents were -1.93, -2.80, and -1.92. The deficit scores were very small for the PNBW adolescents. Paternal education was inversely associated with scores of all 3 groups. Lower paternal education level tended to worsen the negative impact of low birth weight on BCT scores.

CONCLUSIONS

Both lower birth weight and lower paternal education exert an independent and interactive effect on adolescent learning achievement.

Different types of nutritional deficiencies affect different domains of spatial memory function checked in a radial arm maze

Several studies using animal models have suggested that the effects of nutritional insult on the developing brain are long-lasting and lead to permanent deficits in learning and behavior. Malnutrition can refer to the availability of all the nutrients but in insufficient quantities or it may imply that one or more of essential nutrients is either missing or is present, but in the wrong proportions in the diet. The hypothesis addressed in this study is that different domains of cognitive functioning can be affected by malnutrition and this can be related to the type of nutritional deficiency that the brain has been exposed to during development. To study the effect of nutritional deprivation during brain development, a paradigm of maternal malnutrition during the period of gestation and lactation was used and its effects were studied on the F1 offspring using Swiss albino mice. Three different types of malnutrition were used, that involve, caloric restriction, inadequate amount of protein in the diet and condition of low iron content. Our results show that the domain of spatial memory affected in the F1 generation depended on the kind of malnutrition that the mother was subjected to. Further our study shows that although hippocampal volume was reduced in all F1 pups, hippocampal subregions of the F1 animals were differentially vulnerable depending on type of malnutrition that the mother was subjected to. These results highlight the importance of qualifying the kind of malnutrition that is suffered by the mother during the period of gestation and lactation as it has consequences for the cognitive domain affected in the offspring. Awareness of this should inform prevention strategies in trying to reverse the effects of adverse maternal nutrition during critical periods in brain development.

Cognitive and educational outcomes in early adulthood for infants weighing 1000 grams or less at birth

AIM

To assess the intelligence quotient (IQ) and academic achievement in early adulthood of a cohort of extremely-low-birthweight (ELBW 1000 g) subjects.

METHODS

All 82 ELBW survivors consecutively born in or referred to a single tertiary center in 1976-1981 were traced at a mean age of 18 y. Three disabled children had died. Fifty-nine subjects (75%) had their IQ tested and 69 (87%) responded to a questionnaire. They were compared to 44 term, normal birthweight (NBW) matched controls. Outcome measures were: IQ (Wechsler Adult Intelligence Scale) and educational outcome. The main outcome variables were compared between groups and analyzed for neonatal and demographic data and in the ELBW group for childhood data.

RESULTS

There was a strong relationship (r2=0.55, p<0.0001) between childhood and adult IQ for the 41 ELBW subjects tested at both ages (6.1+/-1.3 and 18.4+/-1.9 y). Differences were significant between ELBW and NBW groups: in mean full-scale IQ (94+/-12 vs 108+/-14), verbal IQ (93+/-12 vs 106+/-14) and performance IQ (97+/-14 vs 109+/-16) (p<0.0001). Differences between ELBW and NBW groups in prevalence of IQ<85 (19 vs 2%, p=0.012), of schooling in a regular curriculum for age (36 vs 68%, p=0.0011), of requirement for special classes or schools (33 vs 9%, p=0.0032), and of obtainment of secondary school diploma for those 18 y or older (56 vs 85%, p=0.018) were largely due to fathers' socio-economic score.

CONCLUSION

ELBW subjects had a mean adult IQ in the normal range; however, it was one standard deviation below that of NBW subjects and they had more school failures. Despite this, more than half of ELBW subjects aged 18 y or more had obtained their secondary school diploma.

A “deficient environment” in prenatal life may compromise systems important for cognitive function by affecting BDNF in the hippocampus

The intrauterine environment has the capacity to mold the prenatal nervous system. Particularly, recent findings show that an adverse prenatal environment produces structural defects of the hippocampus, a critical area sub-serving learning and memory functions. These structural changes are accompanied by a disruption in the normal expression pattern of brain-derived neurotrophic factor (BDNF) and its cognate tyrosine kinase B (TrkB) receptor. The important role that the BDNF system plays in neural modeling and learning and memory processes suggests that fetal exposure to unfavorable intrauterine conditions may compromise proper cognitive function in adult life. These findings have implications for disorders that involve a dysfunction in the BDNF system and are accompanied by cognitive deficits.

Maternal antihypertensive therapy with beta-blockers associated with poor outcome in very-low birthweight infants

The progress of 36 very-low birthweight (less than or equal to 1500 g) infants born to mothers with pregnancy-induced hypertonia or pre-eclampsia was studied. During the first year of life, 7 out of 19 infants died when the mothers' antihypertensive regimen included beta-blockers. Four of the deaths occurred within 15 days. There were no deaths in 16 infants whose mothers were treated with other antihypertensive treatment (P = 0.006). These results suggest that maternal beta-blocker therapy may have adverse effects on the very-low birthweight infants.

Patterns of motor disability in very preterm children

Motor development in very preterm children differs in several important ways from that of children born at full term. Variability is common, although the anatomic and physiologic bases for that variability are often poorly understood. Motor patterns over the first postnatal year may depend on behaviours learned during often long periods of neonatal intensive care. The normal pattern of development may be modified by disturbances of brain function caused both by the interruption of normal brain maturation ex-utero and the superimposition of focal brain injuries following very preterm birth. Abnormal patterns of development over the first year may evolve into clear neuromotor patterns of cerebral palsy or resolve, as "transient dystonias." Cerebral palsy is associated with identified patterns of brain injury secondary to ischaemic or haemorrhagic lesions, perhaps modified by activation of inflammatory cytokines. Cerebral palsy rates have not fallen as might be expected over the past 10 years as survival has improved, perhaps because of increasing survival at low gestations, which is associated with the highest prevalence of cerebral palsy. Children who escape cerebral palsy are also at risk of motor impairments during the school years. The relationship of these impairments to perinatal factors or to neurological progress over the first postnatal year is debated. Neuromotor abnormalities are the most frequent of the "hidden disabilities" among ex-preterm children and are thus frequently associated with poorer cognitive ability and attention deficit disorders. Interventions to prevent cerebral palsy or to reduce these late disabilities in very preterm children are needed.

Dendritic morphology is altered in hippocampal neurons following prenatal compromise

Chronic placental insufficiency (CPI), a known cause of intrauterine growth restriction, can lead to structural alterations in the developing brain that might underlie postnatal neurological deficits. We have previously demonstrated significant reductions in the volumes of hippocampal neuropil layers in fetal guinea pig brains following experimentally induced growth restriction. To determine the components of the neuropil affected in the brains of growth restricted (GR) fetuses, the dendritic morphology of CA1 pyramidal neurons and dentate granule cells was examined. CPI was induced by unilateral uterine artery ligation in pregnant guinea pigs at midgestation (term approximately 67 days). Hippocampi from control and GR fetuses were stained using the Rapid Golgi technique and the growth and branching of the dendritic arbors were quantified using the Sholl method. In addition, the density of dendritic spines was determined on the apical arbors of each population. In GR brains (n = 7) compared to controls (n = 7), there was a reduction in dendritic elongation (p < 0.005) and an alteration in the branch point distribution in CA1 basal arbors, and a reduction both in the outgrowth (p < 0.05) and branch point number (p < 0.05) of CA1 apical arbors. Dentate granule cells from GR brains also demonstrated reduced dendritic outgrowth (p < 0.05). There was an increase in dendritic spine density in both neuronal populations; this might be due either to altered synaptic pruning or as a compensatory mechanism for reduced dendritic length. These findings demonstrate that a chronic prenatal insult causes selective changes in the morphology of hippocampal cell dendrites and may lead to alterations in hippocampal function in the postnatal period.

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.

Visual-motor function of very low birth weight and full-term children at 3 1/2 to 4 years of age

Improvements in perinatal and neonatal management have not only led to a higher survival rate of very low birth weight infants (VLBW; < or = 1,500 g or < 32 weeks gestational age), but also to a better outcome of these children. However the percentage of VLBW children who need special education because of later school problems remains high even in children considered neurologically normal during infancy. We assessed 40 VLBW children and 83 healthy full-term children at age 3 to 4 years by means of a simple and short test for visual-motor deficits. The test included the copying and cutting-out of geometric shapes, the building of models, the recognition of colours and the observation of the concentration and cooperation during the test. All VLBW children had had a good perinatal outcome and had been considered neurologically normal at one year of age. Most VLBW children scored within 1 standard deviation (S.D.) of the test mean, but on average the VLBW children scored significantly lower than the full-term infants in the copying of figures, the cutting-out of geometric forms, the building of models and in the overall concentration and cooperation during the test. Children who attended a nursery school achieved significantly better test results. Girls tended to have better results, but this was not statistically significant. Social factors and age had a significantly greater impact on results than perinatal factors. In summary, VLBW children scored significantly less in almost every test item compared to their term peers. Our test battery could serve as a short introductory test to screen for deficits in visual-motor skills, especially in VLBW children.

Indicated versus spontaneous preterm delivery: An evaluation of neonatal morbidity among infants weighing </=1000 grams at birth

OBJECTIVE

The aim of the study was to determine whether infants weighing </=1000 g after birth who are born to women who undergo indicated preterm delivery have different neonatal outcomes than do those born as a result of either spontaneous preterm labor or preterm premature rupture of membranes.

STUDY DESIGN

In a 1-year observational study (1992-1993) the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network collected outcome data for 799 infants whose birth weights were </=1000 g. Only singleton infants with gestational age >20 weeks who were not produced as the result of an induced abortion were included. Our analysis was further limited to infants without major congenital anomalies who survived >2 days, were deemed potentially viable by the obstetrician, and would have undergone a cesarean delivery for fetal indications (N = 411). The primary reason for delivery was categorized as indicated delivery, spontaneous preterm labor, or spontaneous preterm premature rupture of membranes. Selected neonatal outcomes were evaluated among infants born to women in each of these groups. Logistic regression analyses were used to control for the effects of other potentially confounding variables.

RESULTS

A total of 156 of the 411 infants were born to women who underwent an indicated preterm delivery, whereas 160 were born after spontaneous preterm labor and 95 were delivered after preterm premature rupture of membranes. Univariate analyses revealed significantly lower incidences of grade III or IV intraventricular hemorrhage, grade III or IV retinopathy of prematurity, and seizure activity among infants born in an indicated preterm delivery than among those born after spontaneous preterm labor or preterm premature rupture of membranes. However, infants of women who underwent indicated preterm delivery had a more advanced mean gestational age at birth than did those born after spontaneous preterm labor or preterm premature rupture of membranes (28 +/- 2 weeks, 26 +/- 2 weeks, and 26 +/- 1 weeks, respectively, P <.001). Multiple logistic regression analysis was therefore used to control for the disparity in gestational age. Multivariate analyses did not confirm the apparent improvement in neonatal outcome in the indicated delivery group.

CONCLUSION

In this population of infants weighing </=1000 g, selected neonatal outcomes did not differ according to birth by indicated preterm delivery, spontaneous preterm labor, or preterm premature rupture of membranes.

Neuropsychological analysis of the visuomotor problems in children born preterm at < or = 32 weeks of gestation: a 5-year prospective follow-up

Forty-six intellectually normal children born preterm (< or =32 weeks of gestation) without major neurological disabilities and a control group of term children matched for age, sex, and parental educational and occupational status were assessed at the age of 5 years using neuropsychological tests emphasizing perceptual and visuomotor functions. The results show that in terms of cognitive functions these preterm children are a very heterogenous group, but many of them still have problems in visuospatial and sensorimotor functions. The preterm children achieved lower mean scores in tests where coordination and voluntary control of hands in combination with tactile, kinaesthetic, and visuospatial perception were needed. They had most difficulty with drawing directions of lines and in integrating two or more forms. They also had problems with 3-dimensional constructions as well as visual perception of rotated shapes or slopes of lines.

Biological predictors and co-morbidity of attention deficit and hyperactivity disorder in extremely low birthweight infants at school

OBJECTIVE

To examine biological predictors and co-morbidity of Attention Deficit Hyperactivity Disorder (ADHD) and associated academic and social impairment in a cohort of extremely low birthweight of (ELBW) children attending school.

METHODOLOGY

Eight seven (70%) of 125 ELBW children born between 1977 and 1986 were followed prospectively. Neonatal and biological data including cranial ultrasound for 62% of children, formal developmental assessment at 4 or 6 years of age, teacher and parent ADHD questionnaire, parental rating of health status and social impairment and school teacher rating of academic performance was recorded.

RESULTS

Apart from grades 3 or 4 intraventricular haemorrhage in a minority of children, there was no evidence to suggest an association between ADHD and perinatal adversity in ELBW children. Social impairment, academic difficulty and atopic symptoms were significantly related to ADHD.

CONCLUSIONS

Extremely low birthweight children presenting with symptoms of ADHD are likely to suffer social and learning impairment and these, rather than perinatal risk factors, should be the focus of clinical attention.

Longitudinal study of neuropsychological outcome in blind extremely-low-birthweight children

This study evaluated neurological and psychological development in 10 blind children over a 4-year period. Five of the children were born preterm with an extremely low birthweight (ELBW) and a diagnosis of retinopathy, whereas the other five were term. All children received their first neurological examination at a mean age of 10 months and then annual follow ups. In addition, the Bielefeld Developmental Test for Blind Infants and Preschoolers (BDTB) was administered every 6 months (from the ages of 18 to 48 months) to assess developmental outcome in different domains (e.g. cognition, language, gross motor abilities). Results showed a higher number of peri- and neonatal complications in blind ELBW children as well as a significantly higher number of neurological symptoms over the 4-year period. At the mean age of 4 years 10 months, blind ELBW children had a significantly lower body weight, body height, head circumference, and body-mass index compared with the term children. Findings on psychological development revealed that blind ELBW children also had significantly lower scores on all domains covered by the BDTB. Finally, the overall score on the BDTB correlated significantly with gestational age, birthweight, duration of mechanical respiration, and days spent in hospital after delivery.

Neurophysiological assessment of brain function and maturation: I. A measure of brain adaptation in high risk infants

Neurophysiologic assessments using EEG/polysomnographic studies permit the clinician to recognize expected patterns of brain maturation in the healthy neonate. By comparison, one can detect encephalopathic behaviors of newborns who are medically at risk. Severe physiologic expressions of encephalopathy are associated with neuropathologic lesions on postmortem examinations, brain lesions documented on neuroimaging studies, and major neurodevelopmental sequelae of survivors. However, such patterns are observed for only a minority of high risk neonates; less severe encephalopathies occur more frequently in neonates without evidence of brain lesions on imaging studies who either recover from medical illness or who manifest no findings of neurological dysfunction. These subtle and persistent brain disorders are obviously more difficult to detect and grade. This is specifically relevant for preterm infants in whom various degrees of encephalopathy may exist, but whose physiologic behaviors must be distinguished form expected behavioral and neurophysiologic patterns of prematurity. Neonates may express brain dysfunction as altered rates of brain maturation, as compared with expected patterns for a given conceptional age. Neurophysiologic expressions of brain dysmaturity, either from prenatal and/or postnatal stresses, may actually occur in a substantially larger segment of the high risk neonatal population than has been anticipated. EEG-sleep studies can serve as a noninvasive neurophysiologic probe of brain organization and maturation to extend clinical observations to assess the severity and persistence of brain dysfunction in a neonate who may be at risk for later neurodevelopmental compromise.

Intelligence and Learning Disabilities in 6- to 8-year-old Children Weighing under 1000 Grams at Birth

Intellectual ability and learning disabilities (LD) were assessed in a cohort of 33 extremely low-birthweight (1000 grams) children at 6-8 years of age with a psychometric test battery. The children were classified into the following three groups: a LD-suspected group of 9 boys (27.3%), a mentally delayed group of 3 boys and 3 girls (18.2%), and a typically developing group of 6 boys and 11 girls (51.5%). No correlation was found between birthweight and intelligence quotient (IQ) at 6-8 years of age. A negative correlation was found between IQ and gestational age (GA) at a nearly significant level. The mean verbal IQ for the 11 small for gestational age (SGA) children was significantly lower than that of the appropriate for gestational age (AGA) children. The LD-suspected group was characterised by lower scores on spatial relationships and rapid but inaccurate solving of the visuo-motor integration tasks on the Frostig test.

School attainment, cognitive ability and motor function in a total Scottish very-low-birthweight population at eight years: a controlled study

The prevalence of learning problems and of cognitive and motor impairment in a total geographically based very-low-birthweight population (N = 324) was compared at eight years of age with that in a population comprising two classroom peers, matched for gender and age (N = 590). 15 per cent of those with birthweights less than 1000g and 6 per cent of those weighing 1000 to 1499 g attended special schools. Index children in main-stream schools performed significantly less well in tests of neuromotor function than their comparison groups. Their mean IQs were 90.4 and 93.7 for those below and above 1000 g, respectively, while their comparison groups' IQs were 102.5 and 101.2. In all cognitive subscales apart from that testing short-term auditory sequential memory, both index groups were less competent. They were also less able in Word Reading and Basic Number Skills. These children placed heavy demands on mainstream schools, with 52 per cent and 37 per cent of the index groups, respectively, requiring learning support compared with 16 per cent in both comparison groups.

Quality of life among young adults born with very low birthweights

Quality of life (QoL) was assessed in 85 young adults, born in 1971-1974 with birthweights < 1500 g (VLBW) and admitted to the neonatal intensive care unit of the State University Hospital in Copenhagen, Denmark. Their QoL was compared to that of 85 subjects with birthweights > 2500 g (NBW) born in the same period at the State University Hospital. The subjects were interviewed by telephone on the basis of the well-defined theories on QoL by Anton Aggernaes. Quality of life was assessed both in objective terms and as judged by the interviewed person. Subjects born with VLBWs and free of handicaps had QoL scores (both objective and subjective) fully comparable with the NBW group. VLBW subjects reporting various physical and mental handicaps had objective as well as subjective QoL scores significantly lower than the NBW group.

Extremely low birth weight and control infants at 2 years corrected age: a comparison of intellectual abilities, motor performance, growth and health

A 2-year cohort of 63 surviving extremely low birth weight (ELBW) infants was prospectively studied and 60 of these infants, together with 44 normal birth weight control infants, were assessed at 2 years of age for intellectual abilities, motor skills, growth and health. The total ELBW group differed significantly from controls on overall Griffiths developmental quotient (99.3 vs. 103.8 P = 0.02) and in the personal/social subscale (100.7 vs. 106.7 P = 0.01). A subset of 43 of the ELBW infants was identified as low risk at discharge. No statistically significant differences were present between the low risk ELBW subset and controls in intellectual abilities though both the total ELBW group and the low risk ELBW subset differed from controls in fine and gross motor abilities, and in weight at 2 years. The total ELBW group also experienced more frequent ill health and hospital readmission.

[Handicaps in the perinatal period. I. Perinatal pathology and difficulties in school]

BACKGROUND

Major handicaps are closely related to perinatal events. However, relationship of these events with other moderate disabilities such as school problems are still unclear.

POPULATION AND METHODS

A representative sample of 1,408 children at school age and born in Lorraine in 1984 was studied. Two hundred and fifty children with problems were compared with 602 controls without school problems, using a multivariate analysis.

RESULTS

The incidence of school difficulties among 6-year old children (in the last year of nursery school) is 17.8%. Children are at higher risk of school problems if their parents are not (odds ratio [OR] = 7.9) or are poor school graduate (OR = 2.7), if they are boys (OR = 2.0), if they are born at the end of the year (OR = 1.1) and also if they are preterm (OR = 2.7) or small for gestational age (OR = 2.5). Preterm delivery and intra-uterine growth retardation accounted for 9.6% of school difficulties.

CONCLUSION

The relationship between perinatal events and school difficulties warrants to continue with prevention during pregnancy, especially among groups with multiple risk factors.

Clinical and subclinical deficits at 8 years in a geographically defined cohort of low birthweight infants

OBJECTIVE

To determine the prevalence of subclinical deficits in cognitive and motor function in low birthweight infants.

DESIGN

Children of birth weight < or = 2000 g born to mothers resident in Merseyside in 1980-1 assessed using the Wechsler Intelligence Scale for Children (WISC), the Neale analysis of reading ability, and the Stott-Moyes-Henderson test of motor impairment (TOMI). Children attending normal schools assessed with controls matched for age, sex, and class in school. Children attending special schools were assessed unmatched.

SUBJECTS

233 matched index case-control pairs attending normal primary schools and 46 unmatched children attending special schools.

SETTING

Primary and special schools.

MAIN OUTCOME MEASURES

IQ score, reading age in months, and TOMI score.

RESULTS

Index cases when compared with controls had a lower WISC score (mean IQ difference 8.8; 95% confidence interval (CI) 6.8 to 10.7), a lower reading age (mean difference 6.5 months; 95% CI 4.0 to 9.0), and poorer motor performance as shown by the TOMI score (mean difference 1.4; 95% CI 1.1 to 1.8). Of the children attending special schools, 23/46 (50%) had a WISC score < or = 50.

CONCLUSIONS

Low birthweight children have significant subclinical deficits of cognitive and motor function and extra resources, especially in education, may be required to meet their needs.

High-risk preterm infants at 3 years of age: parental response to the presence of developmental problems

In this article we describe developmental status at 3 years and family utilization of early intervention services of 24 children who were born prematurely and weighed less than 1,500 g or who required mechanical ventilation at birth. Findings indicated (a) a low rate of major disabling conditions; (b) a high rate of developmental, mild cognitive, and behavioral concerns; and (c) a lack of family follow-through on referrals for early intervention services for potentially responsive children, even though the concerns put the children at risk for school difficulties.

Neurodevelopmental profile at five years of children born at < or = 32 weeks gestation

Sixty children born preterm (gestational age < or = 32 weeks) and 60 control children matched by sex, and socio-economic and educational status of the parents were followed prospectively to the age of five years. Neurodevelopmental problems were surveyed by a detailed neurological and neuropsychological test battery, and by ophthalmological and hearing examinations. All except one of the preterm children with major disability had motor, visual-spatial and visual problems. The most frequent neurodevelopmental abnormalities encountered among preterm children without major disability were motor problems--emerging as gross and fine motor and/or visual-motor difficulties--and visual-spatial problems. Language difficulties were not associated with hearing problems. Among those without major disability, visual-spatial difficulties and ophthalmological problems seldom emerged simultaneously.

Outcome of infants born preterm, with special emphasis on extremely low birthweight infants

The outcome of extremely low birthweight (ELBW) infants has been reviewed from published articles and up-to-date data from Japan. The mortality rate of these infants declined significantly from over 90% to below 50% after the introduction of intensive care in the 1970s, but the incidence of major neurological sequelae remained steady at around 20%. Similarly, the incidence of major neurological sequelae did not increase along with the decrement of birthweight, although the mortality rate increased significantly. Long-term follow-up of ELBW children until school age has revealed poor school performance in spite of the absence of major neurological sequelae and the attainment of average intelligence quotient scores. Physical growth is retarded initially but generally catches up by the age of 8-9 years. In Japan, the neonatal mortality rate of ELBW infants declined from 56% in 1981 to 25% in 1989 with an increased birth rate of ELBW infants. In ELBW infants cared for at Tokyo Women's Medical College during 1984-90, the survival rate was 112 out of 134 (84%) and the incidence of major neurological sequelae was 15 out of 87 (17%) at 1-8 years old. The viability limit of ELBW infants has been discussed based on recent data. As a result of the rapid progress of medical care of ELBW infants, their viability limit as defined in the Eugenic Protection Law in Japan was amended from 24 completed weeks of gestation to 22 completed weeks in 1991.

Generation differences in hospital inpatient care of children aged 1 to 5 years

STUDY OBJECTIVE

To describe differences in childhood hospital admissions at ages 1 to 5 years in two generations, and to compare the intergenerational differences in risks of admission.

DESIGN

Information was taken from a longitudinal birth cohort study of a national sample and their firstborn offspring.

SETTING

England, Wales, and Scotland.

SUBJECTS

the 5022 birth cohort members for whom information is available from ages 1 to 5 years and their 2205 firstborn offspring.

MEASUREMENTS AND MAIN RESULTS

Data comprised reports of hospital admissions, which were checked with hospitals. Mean numbers of days spent in hospital were fewer in the offspring generation than in their parents, but the proportion ever admitted fell by only 1%. Low birth weight babies (< 2500 g), who comprised 6% of cohort births and 7% of the following generation, used a high proportion of all inpatient time in the offspring population, rising from 3% to 14% of all days of admission.

CONCLUSIONS

Compared with the early years of the NHS, published statistics show that the effectiveness of paediatric care has improved greatly, and that childhood mortality and the risk of serious illness have decreased significantly. This study reports intergenerational changes in the reasons for hospital admission and shows, with the benefit of good denominator data, that although there was only a small intergenerational decrease in the proportion of children treated in hospital, there was a large reduction in the time spent in hospital and an increase in admissions of children of low birth weight.

Outcome at 8 years for children with birth weights of 1250 g or less

The educational, motor, and behavioural performance of a hospital based cohort of 51 children aged 8 years with birth weights of 1250 g or less is reported, as part of a longitudinal study. Compared with age, race and sex matched classmates, who were examined at school at the same visit, the very low birthweight (VLBW) group performed less well on the basic mathematics test A, the Schonell spelling test, and the test of motor impairment. Reading performance was also poorer in this group. Twenty three (45%) VLBW children were having difficulty with one or more school subjects compared with 11 (19%) controls, and 15 (26%) had difficulties in two or more areas, compared with three (5%) controls. Parents of VLBW children reported a similar frequency of behavioural problems to controls but teachers identified characteristics typical of emotional disorders and overactivity more frequently among the VLBW group. Motor testing at 6 years of age was the best predictor of school problems at 8 years, correctly identifying 15/16 children with multiple problems with a low (33%) positive predictive value but a high (98%) negative predictive value. Children with birth weights of 1250 g or less and no major impairment have a high frequency of learning difficulties that become more apparent with advancing age. Such problems may be predicted at an earlier age by detailed motor testing.

The relationship between psychosocial factors and developmental outcome for very low and extremely low birthweight infants: a review

Over the last quarter century, the improved survival rate of very low birthweight infants has sharpened questions about their residual disabilities. Longitudinal studies have devoted attention to the cognitive and neurodevelopmental outcome of these infants, but much less is known about their long-term social and emotional development. Psychiatrists consulting to neonatal intensive care units and assessing these infants in their families, will be assisted by a better understanding of the developmental and psychological outcomes of such infants. This paper reviews the state of knowledge in both of these areas. It argues the paramount importance of psychosocial factors to the infants' developmental outcome, and the importance of longitudinal research in further clarifying the predictive value of these factors. In a subsequent paper, we consider the efficacy of interventions with this group.

Extremely low-birth-weight infants less than 901 g. Growth and development after one year of life

In a long-term prospective control study, 20 extremely low-birth-weight infants with birth weights between 500 and 900 g (mean 755 +/- 109 g) and gestational ages between 24 and 30 weeks (mean 26.2 +/- 1.8 weeks) were compared with 20 full-term infants, after the first year of life for growth, development and continuing morbidity after discharge from the intensive care unit. The total rate of neurological abnormalities was 17%; the rate of infantile post-hemorrhagic hydrocephalus requiring shunt operations was 8.7%, while 13% had retinopathy of prematurity with vision deficit, but none was blind. The hospital readmission rate was 70%, but for most infants only one or a few readmissions were needed whereas three infants with chronic lung disorders required frequent hospital readmissions, mainly for respiratory infections. Apart from 4 infants with major cerebral neonatal complications, 16 of 20 extremely low-birth-weight infants (80%) showed development within the normal range at one year of age, although with delay in some areas in comparison with full-term control infants. Follow-up into preschool and school age is in progress. We cautiously suggest that the results at the one year follow-up do indicate a possible favourable long-term outcome for many of these extremely low-birth-weight infants with normal cognitive development and with no major neurological sequelae.

Extremely low birth weight infants less than 901 g. Impact on the family during the first year

In a longterm prospective study 20 extremely low birth weight (ELBW) infants with birth weight between 500 and 900 g (mean 755 +/- 109 g) and gestational age between 24 and 30 weeks (mean 26.2 +/- 1.8 w) were compared with 20 fullterm infants. This part of the study focuses on the impact on the family. Structured parental interviews were conducted in the postnatal period and at the end of the first year concerning the pregnancy, the delivery and the infant's health and behaviour during the first year of life. Questions about the parents' and siblings' reactions, physical symptoms and the strains on the husband-wife relationship were also asked. It was found that the mothers of the ELBW infants had more fertility problems, more physical symptoms during the pregnancy and the infant's first year of life. The birth of an ELBW infant caused crisis reactions in 85% of the mothers and 65% of the fathers. Fifty-eight per cent of the ELBW parents and 21% of the parents in the control group reported that the stress during the infant's first year had led to strains on the husband-wife relationship. It is evident that the birth of an ELBW infant had an impact on the whole family. However, we found no relationship between permanent neurological injuries in the infant and strong reactions in the family members. On the other hand, the parental relationship in the perinatal period seems to be of significance, as does the length of time the infant was hospitalized during its first year of life.

Evaluation of care for the preterm infant: review of literature on follow-up of preterm and low birthweight infants. Report from the collaborative Project on Preterm and Small for Gestational Age Infants (POPS) in The Netherlands

Since the introduction of neonatal intensive care in the 1960s, mortality in very preterm and very low birthweight infants has been decreasing steadily. Consequently, interest in the outcome of surviving infants is growing. Restriction of health care resources has stressed the need for information concerning the effect of individual treatment components on mortality and morbidity. Concern about the quality in apparently normal survivors has been increasing as well. The current flood of papers on these subjects illustrates the interest in these issues. The first part of this paper reviews the methodology used in follow-up studies in the past decades. It aims at methodological problems that hamper comparison between studies and preclude unequivocal conclusions. New treatment techniques seldom were but should be evaluated by randomised trials. To monitor the combined effects of changing obstetric and neonatal techniques on perinatal outcome, studies in geographically defined populations are recommended using data from early pregnancy until at least preschool age. Comparability of outcomes could be enhanced by international agreement on standardisation of assessment methods and outcome measures. In the second part the results concerning gestational age- and birthweight-specific mortality, impairments and disabilities and the risk factors for such disorders are discussed. Increased survival of even the tiniest infants is clearly established. This increase in survival has not yet been accompanied by an apparent increase in major morbidity. However, many minor impairments are reported, occurring often in combination and predisposing these children to deviations of normal development. Important changes in the manifestation of brain damage appear to occur during development. These findings stress the importance of long-term follow-up studies.

Improving health status in extremely low birthweight children between two and five years

The 5-year outcome of 101 extremely low birthweight (ELBW, < 1000 g) children discharged from the Neonatal Intensive Care Unit was reported. Over this period, there were four post-discharge deaths. The neurodevelopmental impairment rate was 18% overall: cerebral palsy 7%, blindness 3%, deafness 3% and developmental delay 10%. Seventy-one percent of children were readmitted to hospital. The mean number of admissions was 2.4 per child and the mean duration of total hospital stay was 11.3 days per child in the 5-year period. A trend was observed in a reduction in the readmission rate and hospital days in the 2-5-year period compared to the period between discharge and 2 years, though the differences were not statistically significant. The most common reason for readmission was for surgical procedures, primarily aural ventilation tube insertion and tonsillectomy and adenoidectomy. Significant health problems included recurrent wheezing episodes, stridor and croup in the period up to 2 years and otitis media and tonsillitis between 2 and 5 years. There was some catch-up growth, especially in height, between 2 and 5 years. Children with < 800 g birthweight had similar rates of neurodevelopmental impairment and hospital readmission to those of 800-999 g birthweight. However, they experienced more otitis media and pneumonia, had more ear, nose and throat operations, and at 5 years of age, more were below the 3rd centile for weight. This study showed that the health status of ELBW children had improved between 2 and 5 years, but they continued to experience recurrent health problems and hospital readmissions which would have resulted in added financial and emotional burdens to their families.

Regional cerebral glucose metabolism in clinical subtypes of cerebral palsy

Twenty-three children with 4 clinical subtypes of cerebral palsy were studied using 2-deoxy-2(18F)fluoro-D-glucose (FDG) and positron emission tomography (PET). Subtypes included spastic quadriparesis (N = 6), spastic diplegia (N = 4), infantile hemiplegia (N = 8), and choreoathetosis (N = 5). FDG-PET images were correlated with magnetic resonance imaging or computed tomography. Although the location of glucose metabolic abnormalities corresponded, in general, to abnormalities of brain structure demonstrated by structural imaging studies, the distribution of metabolic impairment almost invariably extended beyond the region of anatomic involvement. The following observations in specific subtypes of cerebral palsy were determined with FDG-PET: (1) In spastic diplegic patients, PET revealed focal areas of cortical hypometabolism in the absence of apparent structural abnormality; (2) A relatively normal pattern of cortical metabolism was observed in most patients with choreoathetoid cerebral palsy, despite marked hypometabolism in the thalamus and lenticular nuclei; and (3) In patients with infantile hemiplegia, FDG-PET disclosed symmetric cerebellar glucose metabolism with absence of crossed cerebellar hypometabolism (diaschisis). This finding is contrary to the typical persistence of crossed cerebellar diaschisis in adult patients with acquired cerebral lesions and suggests metabolic recovery due to developmental plasticity. The possibility that FDG-PET may be clinically useful in identifying the cerebral palsy patient with potential learning handicap and in the study of functional recovery or sparing following brain injury should be explored further.

Inguinal hernia in very low birthweight children: a continuing risk to age 8 years

The prevalence of inguinal hernia repair up to 8 years of age was determined in 205 inborn children of birthweight less than 1500 g who had survived to the age of 8 years; 37 (18.0%) of the children required surgery for inguinal hernia, significantly more frequently for boys than girls (32.0% and 3.9% respectively). The cumulative percentage of inguinal hernia operations in boys was 8.7% during primary hospitalization, 20.4% by 2 years, 30.1% by 5 years and 32.0% by 8 years; 36.4% (12 of 33) hernias in boys occurred beyond 2 years of age. The risk of hernia in boys was only marginally higher in those who required assisted ventilation and in those of birthweight less than 1000 g. Very low birthweight infants, particularly boys, are at risk of developing an inguinal hernia not only in infancy but also to at least 8 years of age.

Neonatal follow-up of very low birthweight/extremely low birthweight infants to school age: a critical overview

Neonatal follow-up studies of school age children, published in the last decade, were critically reviewed. Nine studies examined extremely low birthweight infants (less than or equal to 1000 g) and 16 involved very low birthweight infants (less than or equal to 1500 g). The majority of children had age appropriate I.Q. scores, however, there was a greater variability of test scores. There was an increased need for special education or remedial therapy. Visual-motor integration deficits were frequently reported. Behavioural difficulties were described. Fine and gross motor incoordination was identified. There was no conclusive correlation between perinatal course and school outcome. Gender did appear to influence outcome, in the small percent of studies which examined this variable, with females generally faring better. Low socioeconomic status was the most frequently reported predictor of poor outcome. Identified methodological limitations included heterogeneous samples, lack of control groups, high attrition, variable diagnostic criteria and lack of consensus regarding correction for prematurity.

Neurodevelopmental, health, and growth status at age 6 years of children with birth weights less than 1001 grams

The neurodevelopmental, health, and growth outcomes for 28 six-year-old extremely low birth weight (ELBW) (birth weight less than 1001 gm) children were compared with those of 26 control children born at term. The two groups did not differ in mean weight or height, but the ELBW group had smaller head circumferences (p = 0.015). Kaufman mental processing scores correlated with head circumference (p = 0.0003). Significantly more of the ELBW children (61%) had mild or moderate to severe neurologic problems compared with control children (23%) (p = 0.003). Three ELBW children had mild spastic diplegia; one was blind. Eighteen (64%) of the ELBW children had required rehospitalization versus five (20%) of the comparison group. The mean Kaufman Mental Processing Composite was lower for the ELBW group, but when the data were analyzed by maternal education, only those children whose mothers had a twelfth-grade education had significantly lower scores (p = 0.0001). A similar pattern of group differences was seen for scores on visual-motor function (p = 0.0045), visual-perceptual abilities (p = 0.003), and attention span (p = 0.0001). No group differences were seen regarding hyperactivity or parental stress. Overall functional disability among the ELBW children was considered absent in 46%, mild in 36%, and moderate to severe in 18%. There was a significant association (p = 0.029) between classification of handicap at 12 to 34 months and classification at 6 years. No neonatal factors correlated with 6-year outcome. A significant proportion of ELBW children had no severe disabilities, but many had dysfunctions likely to affect learning and behavior in school.

Specific learning disorders: the possible role of brain damage

The causes of many of the more subtle disorders of cerebral function are often obscure. Are they due to impaired development of the brain or to damage to the brain? Particularly if there is no definite evidence of the latter, and when talking to parents, it is better to use such terms as "minimal cerebral dysfunction". However this must not lesson in any way the constant search for the etiology of these disorders. There is no doubt about their frequency, and in one form or another, about one in ten children have special educational needs. There is therefore a major medical contribution to be made to the problems of these children, especially in terms of prevention. A review of the literature shows, among other causes, how often episodes during pregnancy and birth can lead to learning problems during school life. In the future the development of new neuroradiological, and other techniques, will help to explain these common disabilities.

Cognitive abilities and school performance of extremely low birth weight children and matched term control children at age 8 years: a regional study

The intellectual, psychoeducational, and functional status of a regional cohort of extremely low birth weight (ELBW) survivors who weighed 501 to 1000 gm at birth (n = 143) and who were born between 1977 and 1981 was compared with that of control children born at term (n = 145) who were matched for gender, age, and social class. One hundred twenty-nine ELBW survivors (90%) were available; their mean birth weight was 839 +/- 124 gm and mean gestational age 27 +/- 2.1 weeks, and 48 of them weighed less than or equal to 800 gm at birth. Both ELBW and control groups were tested at a mean unadjusted age of 8 years; 113 of 129 ELBW children completed the full test battery, eight blind children had other tests, and eight were not testable. The mean Full Scale IQ (Wechsler Intelligence Scale for Children--Revised) was 91 +/- 16 for ELBW children and 104 +/- 12 for control children (p less than 0.0001). Between 8% and 12% of the ELBW group scored in the "abnormal" range (less than or equal to -2 SD) on the Wechsler IQ and subtests, compared with 1% to 2% of the control group. The ELBW group did less well on the reading, spelling, and mathematics tests (Wide Range Achievement Test--Revised less than or equal to -2 SD: ELBW = 20% to 28%; control = 3% to 10%). The motor performance of the ELBW group (Bruininks-Oseretsky Test of Motor Proficiency less than or equal to -2 SD: ELBW = 20%; control = 1%) and their visual-motor integration (Beery Developmental Test of Visual-Motor Integration less than or equal to -2 SD: ELBW = 21%; control = 6%) were also poorer. Exclusion of 19 ELBW children with neurologic impairments or an IQ less than or equal to 70 or both did not result in significant improvement in Wechsler or achievement measures. Approximately 15% of the ELBW cohort performed in the abnormal range on the Vineland Adaptive Behavior Scales, compared with none of the control group. Although approximately two thirds of the ELBW group were performing in the normal range on intellectual measures, comparison with the control group suggests that, as a group, ELBW children were significantly disadvantaged on every measure tested.

Intellectual and functional status at school entry of children who weighed 1000 grams or less at birth: a regional perspective of births in the 1980s

The intellectual and functional status of a regional cohort of children who weighed 501 to 1000 gm when born between 1980 and 1982 was evaluated at a mean age of 5 1/2 years by standard psychometric tests. Of 90 long-term survivors (survival rate 49%), 78 children (87%) had the full test battery, 5 children (6%) had other tests (4 were blind), and one child was untestable. Most of the mean scores were within 1 SD of the test norms; the lowest scores were in the McCarthy Motor scale and in the Beery Test of Visual-Motor Integration. Children without neurologic impairments and those with an IQ greater than or equal to 68 (n = 60) had higher overall scores but still performed poorly on the Motor subscale and the Beery test. Children who weighed less than 800 gm at birth (n = 28) were similar to those who weighed greater than 800 gm (n = 50), except in the Memory and Motor subscales, in which they performed significantly less well. At a functional level, determined by the Vineland Adaptive Behaviour Scales, two thirds of the children were performing in the adequate range and the remainder in the moderately low to low range. Of the 43 children with no neurosensory impairments and an IQ greater than or equal to 84, 49% were identified (by the Florida Kindergarten Screening Battery) to be at mild to high risk for future learning disabilities. The data from this unselected population provide an unbiased estimate of the prevalence of intellectual and functional problems in children who weighed less than or equal to 1000 gm at birth.

Normative data and the effect of correction for prematurity on test scores in the psychomotor development of extremely low birthweight infants

This study was concerned with the problem how we should allow for gestational age at birth when evaluating psychomotor development in extremely low birthweight (ELBW) infants. The consequences of the use of corrected and uncorrected developmental test scores as to the degree of prematurity were studied in 27 consecutive ELBW children who had been categorized as being normal on neurological and psychological testing at 5 1/2 years. The present study provides evidence that the overall trend of psychomotor development in normal ELBW children is not accelerated, but is guided by maturation of the central nervous system. This study also suggests that there are no significant differences in the predictive value of corrected and uncorrected DQ scores after 2 years of age with respect to IQ scores at 5 1/2 years.

Infants weighing 1,000 g or less at birth. Outcome at 8-11 years of age

34 long-term survivors of a five-year period (1977-1981) weighing 1,000 g or less at birth were followed-up at 8-11 years of age. Three (8.8%) children had severe functional handicap, 7 (20.6%) had moderate impairments with the need of special schooling. Twenty-four (70.6%) attended normal school but 7 (20.6%) with need of special help. The rate of survival was 30% at the single regional intensive centre where this cohort of infants were cared for. Handicapped infants differed significantly from infants with good prognosis in their neonatal requirements for oxygen therapy and in pathological conditions such as birth asphyxia and recurrent apneic spells but no differences in birthweight, gestational age, route of delivery, maternal age, social class, proportions below the tenth percentile and sex were found.

The changing panorama of infantile hydrocephalus and cerebral palsy over forty years--a Swedish survey

The time trends and background of infantile hydrocephalus (IH) and cerebral palsy (CP) are surveyed. The changes in live birth prevalence, disability patterns, associated neuroimpairments and distribution of etiologies are analysed. Both the risk of IH and that of CP sharply increase with decreasing birth weight and gestational age. It is concluded that the remarkably enhanced survival of particularly very preterm infants, those at the highest risk of long-term morbidity, implies an increasing number of impaired children as long as the outcome of survivors is not drastically improved. The data presented are thought to be of relevance as to reconsideration of the effectiveness of perinatal care for preterm babies.