Significance of prenatal, perinatal and postnatal factors in the development of AGA preterm infants at five to seven years

Advances in neonatology. View from a practicing pediatrician

After reviewing the many problems that may be seen by the physician in follow-up care of the preterm infant and family, it is important to take a step back and evaluate the infant as a whole. In the vast majority of instances, the preterm infant will turn out to be normal. In an unfortunate minority, there may be difficult problems that the baby, parents, and caretakers must face. The pediatrician must remain diligent to attend to those problems that are correctable and to assist patients to their full potential.

Personality and behaviour in eight-year-old, non-handicapped children with birth weight under 1500 g

Personality and behavioural characteristics of a population-based cohort of 29 very low-birth-weight (VLBW) infants were compared with those of 29 matched, term controls at eight years of age. The VLBW infants were born to families of lower socioeconomic status (p = 0.04) and had a lower mean IQ (93 versus 104, p = 0.008) and motor abilities (p = 0.028). Based on the questionnaire personality inventory for children, the VLBW children had more learning difficulties and school coping problems, and the VLBW boys had more conduct and emotional problems than the controls. Except for conduct problems, these differences persisted after controlling for socioeconomic status. Generally, there were significant relationships between behaviour, IQ and motor abilities. In conclusion, VLBW may be a risk factor for the development of school coping and behavioural problems independent of socioeconomic status but often coexist with impaired cognitive and neuromotor function.

Qualitative changes in general movements and their prognostic value in preterm infants

Qualitative assessments of general movements have been shown to have considerable power in predicting neurological outcomes in preterm infants with brain damage. In the present study such assessments were made in 35 preterm infants without major neurological problems before term age, born between 27 and 34 weeks gestation, of whom 12 were small-for-gestational-age (SGA). Most infants maintained a normal or (mildly) abnormal quality from 35 weeks postmenstrual age through 6, 12, 18 to 24 weeks corrected age. Seven changed from initially abnormal movements to a normal quality, six of them after 12 weeks. Differences between SGA and appropriate-for-gestational-age infants became less evident with age, particularly after 12 weeks. This was not the case when comparisons were made on the basis of gestational ages below or above 32 weeks. The prediction of neurological and mental outcomes at 1 year also improved after 12 weeks, around which age a major transformation in neural functions occurs. It is concluded that assessments of movement quality are particularly successful in predicting abnormal outcomes in comparison to examinations based on muscle tone and elicited responses.

Neonatal cerebral ultrasound, neonatal neurology and perinatal conditions as predictors of neurodevelopmental outcome in very low birthweight infants

To determine the assessments before discharge from the intensive care unit, that will predict outcome most accurately, a prospective longitudinal study in a cohort of 79 high risk VLBW children was conducted from birth to 3.6 years of age. Birthweight, gestational age, obstetrical and neonatal optimality, neonatal neurological examinations and neonatal cerebral ultrasound were studied in relation to outcome. The best predictor for outcome was a simple cerebral ultrasound classification according to the presence or absence of ventriculomegaly and intraparenchymal damage of any cause. Infants with normal neonatal cerebral scans or abnormal scans without ventriculomegaly almost invariably had a normal neurological outcome. In infants with cerebral lesions with ventriculomegaly the incidence of normal neurological outcome decreased to less than 50%. Intraparenchymal damage was associated with cerebral palsy as well as other (mental and sensori) handicaps in over 85% of the cases. Neonatal neurological examinations at preterm age had additional value in predicting neurological outcome especially in the group with ventriculomegaly. Neither birthweight, nor gestational age, obstetrical or neonatal optimality were independent variables in the prediction of outcome in high risk VLBW children at 3.6 years of age.

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.

Minor neurological dysfunction from birth to 12 years. II: Puberty is related to decreased dysfunction

To determine whether puberty is related to decreased minor neurological dysfunction (MND), 174 children from the Groningen Perinatal Project who had had MND at nine years were re-examined at 12 years. No signs of MND could be demonstrated in 39 of the children, 33 of whom showed at least three signs of puberty. The presence of minor physical anomalies was associated with persisting MND. The authors hypothesise that puberty is related to a decrease in MND, and discuss the role of hormonal changes in relation to the decrease in minor signs. Re-examination at 14 years will be necessary to confirm this hypothesis, since 68 per cent of the children had not yet reached puberty. Children with MND reached puberty no later than those without.

Current developments in the understanding of mental retardation. Part I: Biological and phenomenological perspectives

During the past decade, noteworthy advances have taken place within the field of mental retardation. The application of advanced biological techniques in such areas as molecular genetics and neuroimaging has substantially improved our ability to identify the biological factors that underlie the origin and pathogenesis of an increasing number of mental retardation syndromes. Refined genetic and psychosocial assessments have highlighted the impressive degree of heterogeneity that is present within and across many mental retardation syndromes, stimulating increasing interest and study. This, the first of a two-part review, will focus on recent developments in biological and phenomenological aspects of mental retardation.

The natural history and predictive value of early language delays in very low birth weight infants

A cohort of 28 VLBW (less than or equal to 1500 g) infants was assessed at 1 and 3 years of age for hearing, language development and neurological status. Language delays were detected in 11 (39%) infants at 1 year, and in four (15%) at follow up at 3 years of age (P less than 0.05). Language quotients were significantly associated with perinatal variables at 1 but not at 3 years of age. Infants with neurological abnormalities had significantly lower language quotients at the 3-year follow up. No child with a normal language profile at 1 year exhibited a delay at 3 years of age.

Early fine motor and adaptive development in high-risk appropriate for gestational age preterm and healthy term children

The development of fine motor and adaptive skills during the first 2 years of life is reported in 97 high-risk preterm children and 94 healthy term children. Most stages of fine motor and adaptive development were found to occur at slightly later ages among preterm children. Neurological development was significantly correlated with fine motor and adaptive development in preterm children only. No significant influence of prenatal, perinatal and postnatal variables on fine motor and adaptive development was noted. No significant sex differences were observed in both the term and preterm group. The strongest predictors of later intellectual functioning were fine motor performance at 9 months and fine motor and adaptive skills at 18 to 24 months.

Influence of medical history on assessment of at-risk infants

The influence of knowledge of their medical history on the assessment of at-risk infants was examined. Two at-risk infants, one with a high-risk medical history and one with a low-risk history, were assessed and videotaped using the Movement Assessment of Infants. 41 physical therapists were randomly assigned to assess the videotaped examinations in four groups with different knowledge of the infants' histories (high-risk infant with actual or low-risk history; low-risk infant with actual or high-risk history). The clinical significance of the difference in total risk scores between knowledge conditions of a high-risk history and a low-risk history was greater for the low-risk infant. The higher mean total risk score for the low-risk infant assessed with a high-risk history suggests that false positive results could occur which may alter parents' perceptions and interactions with the infants and consequently influence their development.

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.

Significance of ultrasound appearances in the neurological development and cognitive abilities of preterm infants at 5 years

The developmental outcome at 5 years of age was studied in 93 preterm infants who had been prospectively examined for peri-ventricular leucomalacia (PVL). Standardised neurological examination and developmental assessment, including tests of cognitive function, were carried out. Major sequelae (n = 10) could be ascribed in most cases to the presence of large PVL lesions. Children with normal scans (n = 51), with isolated haemorrhage (n = 15) and with post-haemorrhagic ventricular dilatation (n = 3) had a favourable prognosis. Patients with small focal PVL changes (n = 16) had lower cognitive abilities on the McCarthy scale and presented more abnormal neuromotor signs and more attention deficits when compared to children with normal scans and isolated haemorrhage. Small focal PVL changes seem therefore to interfere with development at 5 years of age and might represent a morphological marker of a more diffuse brain injury. This study demonstrated also the effect of socioeconomic status on outcome at the age of 5 years.

Neurological outcome in high risk weight appropriate for gestational age preterm children at early school age

Neurological development in preterm children with birth weight appropriate for gestational age is reported in two separate groups: a longitudinal study of 97 preterm children and 93 term children as a control group and a cross-sectional study of 249 preterm children. Both preterm groups were regarded as high risk with respect to number of outborns, distribution of gestational age and perinatal risk factors. Neurological outcome at 5-6 years of age in the majority of the preterm children was comparable to that of the term children. However, 15% of boys and 9% of girls in the preterm group were diagnosed as having cerebral palsy. Mild diplegia was most frequently observed; 4% of the children were severely impaired. Fourteen percent of the preterm vs 2% of the term boys and 6-9% of the preterm vs none of the term girls received motor therapy during early school age. There was a small but consistent sex difference in neurological outcome in favour of the term and preterm girls. Effects of drop out rate and of incompleteness of ascertainment are reported in detail.

Intellectual outcome, speech and school performance in high risk preterm children with birth weight appropriate for gestational age

Intellectual development, speech and school performance of preterm infants with birth weight appropriate for gestational age are reported in two separate investigations: a longitudinal study of 97 preterm children and 93 term children as a control group, and a cross-sectional study of 249 preterm children. Both preterm groups were regarded as high risk groups with respect to number of outborns, distribution of gestational age and perinatal risk factors. Intellectual outcome at 5 and 7 years of age in the majority of the preterm children was comparable to that of the term children. However, 8% of the preterm boys and 2% of the preterm girls achieved lower IQ scores than any of the term children. Between 15% and 17% of the preterm boys and 9%-12% of the preterm girls did not attend school at grade level, compared to 4% and 2% in the term group, respectively. Intellectual and neurological development and school performance were higher interrelated in the preterm than in the term children. Articulation defects, stuttering and dysgrammatism occurred more frequently in the preterm than in the term children and in boys more so than in girls.

Predicting developmental outcome at school age from infant tests of normal, at-risk and retarded infants

The predictive validity of developmental testing was investigated in term, preterm and retarded children. Verbal, performance and locomotor development were assessed at various ages and individual development curves constructed. Inter-age correlations between development tests at nine to 24 months and intellectual assessment at seven years revealed a strong effect on prediction for age at testing and level of mental performance. Categorisation by level of mental performance demonstrated that at seven years 98.6 per cent of the children with developmental quotients (DQs) greater than 85 at 24 months achieved IQs greater than 85, while 98.7 per cent of the seven- to eight-year-old children with DQs greater than 85 at nine to 24 months achieved IQs greater than 85. The Griffiths language and performance scores and their combination were the strongest predictors of later intellectual functioning. The social score was of moderate significance, while the locomotor score had no predictive value. Analysis of individual development curves revealed that prediction was hampered in some children by factors not detectable by statistical analysis, such as dissociations in development, organic impairment and major life events. Among the prenatal, perinatal and postnatal variables studied, only socio-economic status was of predictive significance; its effect depended on the level of mental performance and was most marked in term children, but it had no effect on retarded children.