The optimality concept

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.

Outcome studies of low birth weight infants published in the last decade: a metaanalysis

We conducted a metaanalysis and methods review of 80 studies, published in the last decade, that explored the outcome of low birth weight infants; 27% involved infants whose birth weights were less than or equal to 2500 gm (low birth weight), 44% less than or equal to 1500 gm (very low birth weight), and 29% less than or equal to 1000 gm (extremely low birth weight). Problems found in these studies were grouped into three categories: subject and methods issues, environmental factors, and outcome measurement. The combined average intelligence quotient/developmental quotient (IQ/DQ) of all low birth weight groups was 97.77 (SD 6.19); for control subjects the mean IQ/DQ was 103.78 (SD 8.16). This difference was statistically significant but perhaps not clinically significant. No differences in mean IQ/DQ scores were found among the low birth weight, very low birth weight, and extremely low birth weight subgroups. Statistically significant differences among all groups and control subjects were found when categoric data were analyzed, as were differences among the three subgroups; however, the variety of outcome criteria makes interpretation of the categoric analyses difficult.

Follow-up of preterm children. I. Neurological assessment at 4 years of age

In a long-term prospective study, 46 unselected infants born before 35 completed weeks of gestational age were compared with 26 full-term infants. At 4 years of age, 44 preterms and 25 full-terms were available to follow-up. Two preterm children manifested abnormal neurological development, slight spastic diplegia in one case, and psychomotor retardation in the other. Both these cases had already been identified at 18 months of age. Thorough neurological assessment revealed a number of differences between the two groups indicating both delayed neurological maturation and mild dysfunction in the preterms. We drew up a neurological profile to describe these minor neurological signs. The preterms had poorer muscle tone, more spontaneous movements, and were less skilled in certain gross motor functions. They also showed less developed balance reactions, had difficulties in some coordination tests, and asymmetry was more common in neurological functions. In the different subsystems of the neurological profile we also found a greater variation in the preterm group than in the full-term group. There were no significant correlations within the preterm group between the neurological findings at 4 years of age and gestational age, birthweight, and prenatal or perinatal factors.

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

The effects of prenatal, perinatal and postnatal events on developmental outcome at five to seven years of preterm infants with birthweights appropriate for gestational age were investigated in two separate cohorts: one a longitudinal study of 97 infants, the other a cross-sectional study of 249 infants. Among the prenatal variables, the number of minor congenital anomalies was negatively correlated with neurological development, as was the deformation score. The pregnancy optimality score was not significantly related to outcome. Among the perinatal variables, gestational age and birthweight had some significant correlations with development, but birth and neonatal optimality scores were only inconsistently significant in relation to outcome. Socio-economic status was strongly related to language and intellectual development. Infants with gestations of 32 to 36 weeks had a more favourable neurological and intellectual outcome than those born before 32 weeks: however, the former group comprised about 80 per cent of the population studied, so the majority of children with lower function were found in that group.

Correlation of asphyxia and other risk factors with outcome: a contemporary view

The relationships between 14 maternal/prenatal, 24 perinatal and 12 asphyxia-related variables and outcome at 40 weeks, nine, 18 and 36 months were evaluated in a sample of 608 children enrolled in the multi-center National Heart, Lung and Blood Institute Collaborative study. Correlations were weak generally, although they tended to be stronger for perinatal variables and neurological outcome at 36 months. When the maternal/prenatal and perinatal variables (medical/biological), the SES-Composite Index (environmental/psychosocial) and the Early Neuropsychologic Optimality Rating Scale-9 (behavioral/developmental) were used as optimality scales, prediction was enhanced; however, it appeared that the environmental/psychosocial and behavioral/developmental scales were more predictive of 36-month outcome than were medical/biological variable groupings.

The Q-oTc and Q-Tc interval and ionized calcium in newborns

Ionized calcium (CaF), Q-oTc and Q-Tc intervals were determined in 31 full-term healthy newborns, 12 infants subjected to blood exchange transfusion (ET) and 10 infants with verified clinical hypocalcaemia. There was no significant correlation between CaF values and QT intervals. The large fluctuations in CaF during ET did not correspond to any similar change in Q-oTc or Q-Tc intervals. The Q-oTc interval was slightly longer in the hypocalcaemic and the blood exchanged groups compared to controls. The Q-Tc interval was somewhat longer in the ET group. The differences in mean values for QT intervals were fairly small and the ranges wide. ECG findings lack practical implications in diagnosing and following neonatal hypocalcaemia and we therefore recommend the measurement of CaF as a guideline.

Neonatal metatarsus adductus, joint mobility, axis and rotation of the lower extremity in preterm and term children 0-5 years of age

A total of 484 premature children and a control group of 114 healthy term children underwent orthopaedic follow-up from birth to 5 years of age. At birth, metatarsus adductus was found to be more frequent in twins than in single infants (41% vs 16%; P less than 0.01), but occurred with equal frequency in single preterm and term infants (16% vs 12%). By 5 years of age, metatarsus adductus had resolved in all the term but only in 81% of the preterm children (P less than 0.05). In the preterm and term groups, knee axis (mean intermalleolar distance 22.0 mm vs 20.1 mm), tibial torsion (mean angle -1.2 degrees vs + 0.6 degrees) and angle of gait (mean angle + 1.5 degrees vs + 0.7 degrees) at 5 years were statistically insignificant. Hip function at 5 years was similar in normal preterm and term children but significantly decreased in preterm children with cerebral palsy, more so with regard to abduction (56 degrees vs 39 degrees, P less than 0.05) and extension (22 degrees vs 8 degrees, P less than 0.01). The difference between the sexes was insignificant in both the preterm and term groups.

Hemiplegic cerebral palsy. Aetiology and outcome

Hemiplegic cerebral palsy (CP) was studied in a retrospective population-based series of 169 cases from the South-western Swedish health care region covering the birth years 1969-78. The purpose was to analyse the prevalence, aetiology and neuro-developmental outcome in children born preterm and at term, and to correlate pathogenetic periods, aetiological factors and clinical parameters to neuroradiology. The prevalence at the ages 6-15 years was 0.66 per 1000. Postnatally acquired hemiplegia, mainly postinfectious, iatrogenic or posttraumatic, constituted 11%. Among term children with congenital hemiplegia (pre and perinatally derived) the aetiology was considered prenatal, mainly circulatory brain lesions and maldevelopments, in 42%, combined pre and perinatal in 9%, perinatal (cerebral haemorrhage, hypoxia) in 16% and untraceable in 34%. The corresponding distribution among preterm children was 29%, 47%, 25% and 6%, respectively. The rate of preterm birth among congenital cases was 24%. Birth asphyxia was shown to be a poor indicator of pathogenetic period, whereas a cascade of postpartum complications suggested perinatal brain damage. Clinical follow-up of 152 children revealed that 50% had mild, 31% moderate and 19% severe motor dysfunction. Stereognostic sense was impaired in 44% of the children (astereognosia in 20%). Additional impairments (mental retardation, epilepsy, impaired vision, hearing and speech, severe behavioural/perceptual problems) were present in 42%. Term children with congenital hemiplegia tended to be more severely affected than preterm children. The resulting total handicap was considered mild in 40%, moderate in 44% and severe in 16%. The prevalence of severe total handicap was highest among postnatal cases. Computerised tomography (CT), performed in 109 congenital cases, was normal in 26%, showed unilateral ventricular enlargement in 36% and revealed cortical/subcortical cavities in 20%. In the remaining 18% CT findings were classified as "other". With the classification so far used, correlations between CT findings and aetiologies were unsatisfactory and disappointing. In contrast, CT findings showed a strong correlation with clinical degree of severity and magnitude of associated handicap. As a rule, normal CT implied mild disability and unilateral ventricular enlargement moderate, whereas cortical/subcortical cavities were frequently associated with severe handicap, including mental retardation and epilepsy.

Linking prenatal and perinatal adversities with child development

Several professional groups share an interest in the effects of prenatal and perinatal adversities on children's development. The aim is to present a conceptual and methodological framework which will foster multidisciplinary study in this area. Recent evidence and principles about early life adversities, and developmental processes, are reviewed. The limitations of studies which address discrete variables at single points in time are highlighted. The proposal is that reproductive adversities are most effectively conceptualized as perturbations of infants' endogenous and social regulatory systems, which lead to adaptive developmental processes. The origins of maladaptations are to be found not simply in fixed, within-the-child, characteristics but in an understanding of regulatory processes; particularly the regulatory exchange between child and caregivers. A study is used to illustrate the translation of the model into research design.

Obstetrical and neonatal risk factors in very low birth weight infants related to their neurological development

An analysis of pre- and perinatal risks in very low birth weight (VLBW) infants showed that children later suffering from severe neurodevelopmental sequelae were exposed to a significantly higher number of risk factors compared to normally developed VLBW controls. This was not only due to a higher incidence of specific risks, but to the accumulation of risk factors, which consequently made an ischaemic or haemorrhagic brain lesion more likely to occur. This result suggests that brain lesions in VLBW infants are essentially multifactorial. The improved outcome of VLBW infants cared for in the NICU of the Children's Hospital of Tübingen during 1977-1983 was accompanied by a decreasing incidence of obstetrical and neonatal risks. This was mainly due to more frequent transport in utero, earlier obstetrical intervention, and immediate postnatal stabilization of the infant's condition. These changes in perinatal care strategy evidently favoured the postnatal course and thus also improved the neurodevelopmental outcome.

Language development of term and preterm children during the first five years of life

Language development during the first five years is reported for 114 high-risk preterm children (20 with varying degrees of cerebral palsy) and 97 healthy term children. Most stages of language development occurred at slightly later ages among the neurologically unimpaired preterm children than among those born at term. Preterm children with cerebral palsy were more delayed and had more articulation defects compared with neurologically unimpaired preterm children. Girls were more advanced in early language development and showed less articulation defects than boys. The perinatal optimality score was significantly correlated with the ages at which the stages of language development were reached, and with language performance at five years in preterm children, but much less in term children. Birthweight and gestational age were negatively correlated with language development at all ages. Socio-economic status and birth order had an age-related influences on language development, but no correlation was found with the number of minor congenital malformations.

Apgar score, meconium and acidaemia at birth in relation to neonatal neurological morbidity in term infants

The relation between Apgar score, meconium and acidaemia at birth and neonatal neurological morbidity was investigated in 805 vaginally born term infants whose birthweight was appropriate-for-dates (AFD). Presence or absence of meconium stained amniotic fluid was not related to the neonatal neurological condition. The 1-min and 3-min Apgar scores and the umbilical artery pH were related, but the variances explained in neonatal neurological optimality score were very low (0.9 and 0.5% respectively). Combination of Apgar score and pH slightly increased these percentages to 1.5. The highest frequency of neurologically deviant infants was, on the other hand, found in the group with a normal pH but low Apgar score. It is concluded that in AFD term infants nowadays the predictive value of a low Apgar score, acidaemia at birth and/or presence of meconium for the neonatal neurological morbidity is poor. Most neonatal neurological abnormalities must be due to other factors.

Teenage psychoses--epidemiology, classification and reduced optimality in the pre-, peri- and neonatal periods

This is a population-based survey from Göteborg, Sweden, of all youngsters treated as in-patients for operationally defined 'psychotic disorders' during their teens. It was shown that 0.54% of all teenagers in Göteborg had been treated for such disorders at least once during the 13- to 19-year-old age period. Boys and girls were about equally affected, but schizophreniform disorders tended to be much more common among the boys and affective disorders more common among the girls. Child psychiatric services had been consulted much less frequently than adult ones, in spite of the many developmental aspects of the psychotic disorders. Scores for reduced optimality in the pre- and perinatal periods were marginally, though significantly, more common in the psychosis groups than in an age-, sex- and maternity clinic-matched control group.

Early development of locomotion: significance of prematurity, cerebral palsy and sex

Data on the development of locomotion during the first two years of life were collected for 128 preterm infants (21 with varying degrees of cerebral palsy) and for 111 healthy term infants. Most stages of locomotion occurred at slightly later ages among the neurologically unimpaired preterm infants than among those born at term (age corrected for prematurity). There was no difference between preterm and term infants with regard to the number and types of pathways of locomotion, or to age at onset and type of first movements through space. By 9.5 months of age, 95 per cent of term infants and 92 per cent of preterm infants showed some ability to move through space. The infants with severe cerebral palsy had considerable delay in the development of locomotion, but this occurred to only a minor extent when the degree of cerebral palsy was mild or moderate. Most stages of locomotion occurred at slightly earlier ages for boys than for girls, but these differences were not significant at any age. The number and types of pathways of locomotion, and types of first movements, were comparable in both sexes.

Growth and development in preterm infants during the first 18 months

In a long-term prospective study 46 unselected infants born before 35 completed weeks of gestational age were followed up, and compared to 26 fullterm infants. At 9 and 18 months of chronological age their height and weight were still lower than that of fullterms, but the difference disappeared when age was corrected for gestational age at birth. The motor and neurological maturity and language development was delayed in the preterms still at 18 months, which could possibly also be explained by their lower biological age. Ten of the preterm infants showed, at one or several occasions during follow up, definite neurological abnormality. At 18 months of age two of them were handicapped, one with retrolental fibroplasia, nearly blind, and another with cerebral palsy (slight spastic diplegia). Five of them had late psychomotor development, while two were borderline and one normal. We defined pre- and perinatal risk groups, but found that development at 18 months was not correlated to degree of risk. Neither was there any correlation between neurological examination at term and later handicap or psychomotor retardation. We found more illness, mostly due to common infections, during the first 18 months in the preterm group, as measured by the number of visits to a doctor and days spent in hospital.

Fetal responses to vibrotactile stimulation, a possible predictor of fetal and neonatal outcome

This study measured the antenatal fetal heart rate changes in response to a single vibrotactile stimulus. In a group of 11 normal patients, this resulted in a significant change in the fetal heart rate (P less than 0.001). Sixty-eight high risk patients were also tested. In the group of 25 patients whose fetuses showed no response to the stimulus, there were 4 stillbirths and 4 neonatal deaths; 23 of these 25 infants were small for gestational age (SGA) compared to only 15 of the 43 that showed a response to the stimulus. Fetal habituation to a repeated vibrotactile stimulus was measured in a control group of 40 patients who had a normal antepartum and intrapartum course and delivered infants in an optimal condition. The same was done in a study group of 48 patients who delivered infants that were SGA. These infants were assessed at 1 year of age by the Griffiths Mental Developmental Scale (GMDS). Infants that were SGA did not differ significantly from the control group. However, infants who had a normal antenatal habituation pattern had a significantly better performance (P less than 0.01) compared to infants who had an abnormal antenatal habituation pattern.

Handedness in Swedish 10-year-olds. Some background and associated factors

Forty-five left-handed and 46 right-handed 10-year-old children were subjected to a limited set of neurological tests and a square tracing task. 'Pathological' handedness was diagnosed in cases showing poor performance with the non-preferred hand on the squares task. The frequency of left-handedness in the population was estimated at 9.2%. The boy : girl ratio was 1.6:1. 'Pathological' handedness was twice as common among left-handers as among right-handers. Neurological dysfunction was more common in 'pathological' handers, especially left-handers. Reduced pre-. peri- and neonatal optimality was seen in boys with 'pathological handedness'. School achievement problems and behaviour problems were much more common in left-handed boys than in other study groups. The results lend partial support for the extended pathological left-handedness model recently hypothesized by Bishop, but it is suggested that left-handedness in boys is more often a symptom of pathological shift of handedness than is left-handedness in girls.

Factors associated with the intellectual ability of children born to women with high risk pregnancies

The intellectual abilities of 242 children born to women who had been hypertensive during pregnancy were assessed at the age of 7 1/2 years. Associations between 15 maternal, fetal, perinatal, postnatal and environmental factors, and test scores were investigated. After adjustment for confounding variables children in the upper social classes, born to non-smokers, who were first born, breast fed, and with birth weights above the 10th centile had significantly higher scores in some aspects of ability than the rest. Children whose mothers had developed superimposed pre-eclampsia had higher scores than those whose mothers had not suffered preeclampsia; and children delivered by elective caesarean section had lower scores than those delivered spontaneously. In a small subgroup of women with particularly high risk pregnancies perinatal mortality had been 10 times greater than in the rest of the sample. At 7 1/2 years the intellectual ability of the survivors in this subgroup did not differ from that of the rest. These findings do not support the notion that there is a quantitative continuum of "reproductive casualty" from mortality to morbidity.

The prediction of preterm labour by recording spontaneous antenatal uterine activity

The recording of spontaneous antenatal uterine activity was assessed as a predictor of preterm labour in a group of patients considered at high risk on the basis of a past history of preterm delivery. The recording of individual uterine contractions greater than or equal to 15 mmHg between 20 and 28 weeks gestation was found to be useful for the prediction of preterm labour in this high risk group.

Neurological assessment of preterm infants at term conceptional age in comparison with normal full-term infants

In a long-term prospective study 46 unselected infants born before 35 weeks of gestational age were followed up, which included repeated neurological and psychological examination. 40 of them were neurologically evaluated at term conceptional age and compared with 26 full-term newborns, all the infants being considered healthy. There was no difference in mean weight or length between the two groups, but mean head circumference was greater in the preterm group. The preterm infants had lower muscle tone as judged by spontaneous posture of arms and legs, and poor resistance to passive movements and slow arm recoil. In the traction test they had more head lag. The withdrawal and Moro reflexes were weaker, while asymmetric tonic neck reflex (ATNR) was easier to elicit. Head control in the sitting position was better. All infants were evaluated with a prenatal and perinatal optimality score, which was not however significantly correlated with the neurological findings. The preterm infants with only slightly reduced optimality score (low risk group) had approximately the same birth weight and gestational age as the other preterms. They more resembled the full-term infants with good resistance to passive movements, fast arm recoil and good responses concerning the withdrawal and Moro reflexes. However, they had a semiflexed position in supine and thus in this respect were more like the other preterms.

Infantile autism: a total population study of reduced optimality in the pre-, peri-, and neonatal period

Twenty-five autistic children, constituting a total population sample of children with infantile autism, were compared with 25 sex- and maternity-clinic-matched controls for occurrence of reduced optimality in the pre-, peri, and neonatal period, as noted in medical records. Autistic children showed greatly increased scores for reduced optimality, especially with regard to prenatal factors. The findings are at odds with early reports that children with autism had not suffered potential brain injury. The reasons for the discrepancy are discussed.

Visuo-motor behaviour in pre-school children in relation to sex and neurological status: an experimental study on the effect of 'time-pressure'

A detailed analysis was made of the visuo-motor behaviour of 139 pre-school children during a spatial-constructive task with and without time-pressure. The study focused mainly on sex differences and the implications of minor neurological dysfunctions for children's visuo-motor behaviour. Between sexes only minor differences in behavioural organization and efficiency were found. Between neurological groups only differences within the girls were found, those with lower neurological optimality scores showing more signs of 'lack of motor inhibition' and distraction in the prestress condition, seemingly related to differences in motivation. No effect was found for time-pressure for groups with a different neurological status.

The assessment and significance of habituation to a repeated stimulus by the human fetus

Habituation is the progressive decrease in response by an organism when it is stimulated repeatedly. This process is a basic form of learning and a normal pattern may be one indication of intact central nervous system function. This study assessed habituation of a behavioral response by the human fetus to repeated vibrotactile stimuli. Of the 40 normal fetuses studied 37 habituated after 10 to 50 stimuli. The gestational age at which the fetus first responded to the stimulus ranged from 22 to 30 weeks. Female fetuses responded 2 weeks earlier than males. The possible value of this assessment in obstetrical practice is presented.

Fetal habituation in high-risk pregnancies

Habituation is a basic form of learning and probably requires an intact central nervous system. Habituation in the behavioural response to vibration in 40 normal human fetuses was compared with that in a group of high-risk pregnancies with an increased risk of fetal neurological damage. Highly significant differences in habituation patterns between the high-risk groups and normal control subjects were found. This test may offer a method of assessing the integrity of the fetal central nervous system.