Effects of birth weight and sociodemographic variables on mental development of neonatal intensive care unit survivors

Brain Development and Maternal Behavior in Relation to Cognitive and Language Outcomes in Preterm-Born Children

BACKGROUND

Children born very preterm (≤32 weeks gestational age) show poorer cognitive and language development compared with their term-born peers. The importance of supportive maternal responses to the child's cues for promoting neurodevelopment is well established. However, little is known about whether supportive maternal behavior can buffer the association of early brain dysmaturation with cognitive and language performance.

METHODS

Infants born very preterm (N = 226) were recruited from the neonatal intensive care unit for a prospective, observational cohort study. Chart review (e.g., size at birth, postnatal infection) was conducted from birth to discharge. Magnetic resonance imaging, including diffusion tensor imaging, was acquired at approximately 32 weeks postmenstrual age and again at term-equivalent age. Fractional anisotropy, a quantitative measure of brain maturation, was obtained from 11 bilateral regions of interest in the cortical gray matter. At 3 years (n = 187), neurodevelopmental testing (Bayley Scales of Infant and Toddler Development-III) was administered, and parent-child interaction was filmed. Maternal behavior was scored using the Emotional Availability Scale-IV. A total of 146 infants with neonatal brain imaging and follow-up data were included for analysis. Generalized estimating equations were used to examine whether maternal support interacted with mean fractional anisotropy values to predict Cognitive and Language scores at 3 years, accounting for confounding neonatal and maternal factors.

RESULTS

Higher maternal support significantly moderated cortical fractional anisotropy values at term-equivalent age to predict higher Cognitive (interaction term β = 2.01, p = .05) and Language (interaction term β = 1.85, p = .04) scores.

CONCLUSIONS

Findings suggest that supportive maternal behavior following early brain dysmaturation may provide an opportunity to promote optimal neurodevelopment in children born very preterm.

Memories of Infant Pain in the Neonatal Intensive Care Unit Influence Posttraumatic Stress Symptoms in Mothers of Infants Born Preterm

OBJECTIVES

The birth of a preterm infant and witnessing ones' infant in pain is remembered by parents as being one of the most stressful aspects of the neonatal intensive care unit (NICU). Elevated posttraumatic stress symptoms (PTSS) are highly prevalent among mothers of preterm infants, however, little is known about mothers' memories of invasive procedures in the NICU and how these memories may contribute to the development of PTSS. We examined the relationships between number of invasive procedures, mothers' memories of these procedures, and their PTSS at discharge from the NICU.

MATERIALS AND METHODS

Participants included 36 mothers of infants born below 37 weeks gestational age recruited from a tertiary-level NICU. Medical chart review was performed between birth and discharge from the NICU. At discharge, a research nurse conducted a structured memory interview with the mothers to assess their memories of their infants' invasive procedures. Mothers also completed a self-report measure of PTSS (Posttraumatic Stress Disorder Checklist for the DSM-5).

RESULTS

Mothers of infants exposed to greater numbers of invasive procedures had more elevated PTSS at discharge (R=0.37). Moreover, mothers who recalled having greater anxiety about their infant's invasive procedures had greater symptoms of reexperiencing (R=0.34) and avoidance (R=0.28) at discharge from the NICU.

DISCUSSION

Greater neonatal exposure to invasive procedures and mothers' recall of these procedures were related to mothers' posttraumatic stress symptomatology at discharge. Invasive procedures in the NICU represent an important target area for neonatal intervention to reduce maternal distress and improve outcomes.

Resilience priming: Translational models for understanding resiliency and adaptation to early life adversity

Despite the increasing attention to early life adversity and its long-term consequences on health, behavior, and the etiology of neurodevelopmental disorders, our understanding of the adaptations and interventions that promote resiliency and rescue against such insults are underexplored. Specifically, investigations of the perinatal period often focus on negative events/outcomes. In contrast, positive experiences (i.e. enrichment/parental care//healthy nutrition) favorably influence development of the nervous and endocrine systems. Moreover, some stressors result in adaptations and demonstrations of later-life resiliency. This review explores the underlying mechanisms of neuroplasticity that follow some of these early life experiences and translates them into ideas for interventions in pediatric settings. The emerging role of the gut microbiome in mediating stress susceptibility is also discussed. Since many negative outcomes of early experiences are known, it is time to identify mechanisms and mediators that promote resiliency against them. These range from enrichment, quality parental care, dietary interventions and those that target the gut microbiota.

Parent behaviors moderate the relationship between neonatal pain and internalizing behaviors at 18 months corrected age in children born very prematurely

Children born very preterm (≤ 32 weeks gestation) exhibit greater internalizing (anxious/depressed) behaviors compared to term-born peers as early as 2 years corrected age (CA); however, the role of early stress in the etiology of internalizing problems in preterm children remains unknown. Therefore, we examined the relationship between neonatal pain and internalizing behavior at 18 months CA in children born very preterm and examined whether parent behavior and stress moderated this relationship. Participants were 145 children (96 very preterm, 49 full term) assessed at 18 months CA. Neonatal data were obtained from medical and nursing chart review. Neonatal pain was defined as the number of skin-breaking procedures. Cognitive ability was measured with the Bayley Scales of Infant Development II. Parents completed the Parenting Stress Index III, Child Behavior Checklist 1.5-5, and participated in a videotaped play session with their child, which was coded using the Emotional Availability Scale IV. Very preterm children displayed greater Internalizing behaviors compared to full-term control children (P=.02). Parent Sensitivity and Nonhostility moderated the relationship between neonatal pain and Internalizing behavior (all P<.05); higher parent education (P<.03), lower Parenting Stress (P=.001), and fewer children in the home (P<.01) were associated with lower Internalizing behavior in very preterm children, after adjusting for neonatal medical confounders, gender, and child cognitive ability (all P>.05). Parent Emotional Availability and stress were not associated with Internalizing behaviors in full-term control children. Positive parent interaction and lower stress appears to ameliorate negative effects of neonatal pain on stress-sensitive behaviors in this vulnerable population.

Declining cognitive development from 8 to 18 months in preterm children predicts persisting higher parenting stress

BACKGROUND

Higher parenting stress in mothers of children born very preterm may be in part a response to poorer neurobehavioral development, reflecting realistic concerns in addition to adaptation to the trauma of preterm delivery. To our knowledge, there are few longitudinal studies of parenting stress that have addressed child cognitive competence.

AIMS

To examine parenting stress in preterm and full-term children at 8 and 18 months corrected chronological age (CCA), in relation to child cognitive development and behavior.

SUBJECTS

Participants were N=152 children (98 preterm born ≤32 weeks gestation, and 54 full-term) seen at 8 and 18 months CCA, and the primary caregiver parent. STUDY DESIGN/OUTCOME MEASURES: The Parenting Stress Index questionnaire was completed by a parent, child interactive behavior was videotaped, and the Bayley Scales of Infant Development (BSID II, Mental Development Index; MDI) were administered at both ages.

RESULTS

Total Parenting Stress was higher in preterm than full-term children at 8 and 18 months CCA (p<.02), accounted for primarily by the Child domain. Hierarchical regression showed (after controlling for neonatal risk, number of children in the home, child interactive behavior and maternal education) that decreasing Bayley MDI scores from 8 to 18 months CCA predicted higher parenting stress for preterm children. For full-term children, number of children in the home and child interactive behavior predicted parental stress at 18 months.

CONCLUSION

Higher parenting stress persisting to 18 months CCA in preterm children may partly reflect realistic parental concerns with their child's development.

Neonatal pain, parenting stress and interaction, in relation to cognitive and motor development at 8 and 18 months in preterm infants

Procedural pain in the neonatal intensive care unit triggers a cascade of physiological, behavioral and hormonal disruptions which may contribute to altered neurodevelopment in infants born very preterm, who undergo prolonged hospitalization at a time of physiological immaturity and rapid brain development. The aim of this study was to examine relationships between cumulative procedural pain (number of skin-breaking procedures from birth to term, adjusted for early illness severity and overall intravenous morphine exposure), and later cognitive, motor abilities and behavior in very preterm infants at 8 and 18 months corrected chronological age (CCA), and further, to evaluate the extent to which parenting factors modulate these relationships over time. Participants were N=211 infants (n=137 born preterm 32 weeks gestational age [GA] and n=74 full-term controls) followed prospectively since birth. Infants with significant neonatal brain injury (periventricular leucomalacia, grade 3 or 4 intraventricular hemorrhage) and/or major sensori-neural impairments, were excluded. Poorer cognition and motor function were associated with higher number of skin-breaking procedures, independent of early illness severity, overall intravenous morphine, and exposure to postnatal steroids. The number of skin-breaking procedures as a marker of neonatal pain was closely related to days on mechanical ventilation. In general, greater overall exposure to intravenous morphine was associated with poorer motor development at 8 months, but not at 18 months CCA, however, specific protocols for morphine administration were not evaluated. Lower parenting stress modulated effects of neonatal pain, only on cognitive outcome at 18 months.

Difficultés de suivi d'une cohorte d'enfants nés grands prématurés : EPIPAGE Paris–Petite-Couronne

OBJECTIVES

To describe the characteristics of the children of parents who did not respond to a follow-up questionnaire in a cohort of very preterm infants (EPIPAGE study) and to explore the reasons why they did not complete the questionnaires.

METHODS

The non-respondents (N = 176) were the parents who did not return the questionnaires at 1 and 2 years. Contacts were organised by telephone calls and at home visits.

RESULTS

The families of the non-respondents presented more socioeconomic difficulties and their children were born more preterm than those followed up without difficulties. The efforts made to contact the non-respondents revealed that their families were often confronted with major adverse socioeconomic difficulties, had severe illnesses and psychological troubles. Half of the children of the non-respondents were finally examined at the 5-year assessment. They showed lower performances at the cognitive development test and a poorer health status than the children of the respondents.

CONCLUSION

When the follow-up does not include the initial population in its totality, the socioeconomic difficulties are underestimated and probably also the rate of sequelae associated with very preterm delivery.

Birth weight and cognitive development in adolescence: causal relationship or social selection?

Using data from the National Longitudinal Survey of Adolescent Health (Add Health), I investigate the relationship between birth weight and cognitive development among adolescents aged 12-17. Initial OLS regression models reveal a significant, positive relationship between low birth weight and verbal ability. Controlling for demographic, socioeconomic, and other adolescent characteristics modifies, but does not eliminate, this relationship. Additional models that stratify the sample by parental education illustrate the greater importance of other family and adolescent characteristics for cognitive development in adolescence, and a diminished role of birth weight. In the final section of the paper, fixed effects models of non-twin full siblings indicate no significant association between birth weight and verbal ability, suggesting that traditional cross-sectional models overstate the influence of birth weight for cognitive development in adolescence.

A risk assessment screening test for very low birth weight

OBJECTIVES

To develop a risk-assessment screening tool for very low birth weight (VLBW) and to compare our empirically derived tool to the nonempirically derived screening tool used by the State of Florida.

METHODS

Birth records from the State of Florida Vital Statistics between 04/01/92 and 12/07/94 were matched with State Healthy Start prenatal records, reported from 04/01/92 through 03/31/94. Known and additional potentially important risk factors were identified from both sources. Generalized Linear Modeling techniques were used to estimate associations between risk factors and VLBW. A risk assessment system was then developed using the estimated model. The resulting screening test was compared with the one used by the Florida State Department of Health in terms of sensitivity and specificity on an independent validation sample.

RESULTS

The proposed screening tool had comparable specificity to the Healthy Start screening tool but significantly better sensitivity. Both instruments are simple and easy to implement.

CONCLUSIONS

Identification of women at high risk for VLBW would be improved using the model-based screening tool developed in this paper. Public health policy makers should use statistical methods in addition to expert opinion to improve existing risk assessment methods. The actual value of an improved screening instrument is dependent on the availability of effective intervention programs.

[A comparative study of the perceptual and motor performance at school age of preterm and full term children]

The objective of this study was to compare the perceptualmotor performance in school age children who were born preterm and full term. Two groups of children, ages 5 to 7, participated in this study. Group I had 35 children, from low-income families, born up to the 34 week of gestation and/or weight bellow 1500 g. Group II had 35 full-term children, matched by age, gender and socioeconomic status to the children in Group I. Children were tested on the Bender gestalt, the motor accuracy test and on balance and postural responses measures. The preterm group obtained significantly lower scores in the majority of the tests. These besides reinforcing the importance of the follow-up of preterm children up to school age, also indicate the need to stimulate the fine motor and postural control Devment, even among preterm children who do not show evidence of neurological impairment.

Developmental outcome at 18 and 24 months of age in very preterm children: a cohort study from 1996 to 1997

OBJECTIVE

To determine the effect of prematurity (gestational age (GA) < 32 weeks) on developmental outcome at the corrected age of 18 and 24 months in a regionally defined, prospective cohort study.

STUDY DESIGN

The Leiden Follow-Up Project on Prematurity (LFUPP) includes all live-born infants < 32 weeks GA, born in 1996/1997 in three Dutch health regions (n=266). Mental and psychomotor developmental indices (MDI, PDI) were determined with the Bayley Scales of Infant Development I: > or = -1 S.D.: normal, -2 to -1 S.D.: moderate delay and < -2 S.D.: severe delay.

RESULTS

At 18 months 168 (71%) and at 24 months, 151 children (64%) of 235 survivors were assessed. Moderate to severely delayed mental and/or psychomotor development occurred in 40% of the children at both ages. Children lost to follow-up were of lower socioeconomic status and more frequently of non-Dutch origin. Since non-Dutch origin negatively affected the outcome at both test ages, availability of the data of these children would probably have worsened the outcome. Postnatal treatment with dexamethasone was associated with an increased risk of delayed development. Other independent predictors of delayed development were bronchopulmonary dysplasia at 18 months and ethnicity, maternal age at birth, birthweight and gender at 24 months. After adjustment for these other predictors of delayed development, the mean PDI of dexamethasone-treated infants was 16.1 points lower than of non-treated infants at 18 months (p=0.03) and 12.7 points lower at 24 months (p=0.04).

CONCLUSIONS

At 18 and 24 months corrected age, 40% of the very prematurely born children had both delayed mental and/or psychomotor development. Treatment with dexamethasone postnatally was a major risk factor for delayed (psychomotor) development.

Behavioral/environmental intervention improves learning after cerebral hypoxia-ischemia in rats

BACKGROUND AND PURPOSE

In premature infants, many of whom experience ischemic brain insults, the environment of rearing influences cognitive outcome. We developed a model to evaluate the effect of rearing conditions on learning after unilateral cerebral hypoxia-ischemia (HI) in 7-day-old (P7) rats. We hypothesized that neonatal handling would benefit rats recovering from an episode of HI.

METHODS

Seventeen litters of P7 Long-Evans rats underwent either HI (right carotid ligation followed by 1.5 hours in 8% O(2)) or control procedures. From P8 to P14, randomized litters were either handled (15 minutes of separation from dam per day) or nonhandled. After P55, learning was tested in the Morris water maze. To evaluate injury severity, hippocampal, cortical, and striatal volumes were measured.

RESULTS

In water-maze performance, ANCOVA revealed an interaction between handling and severity of hippocampal damage. Among HI rats, handled rats learned faster when hippocampal damage was moderate (P<0.01, repeated-measures ANOVA), with no benefit when damage was mild or severe.

CONCLUSIONS

These observations suggest the beneficial cognitive effect of neonatal handling was limited to animals with moderate damage. Neonatal handling in post-HI rats may be a useful model in which to study mechanisms underlying the benefits of post-HI developmental intervention.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The impact of low birth weight, perinatal conditions, and sociodemographic factors on educational outcome in kindergarten

OBJECTIVE

To assess the relative effects and the impact of perinatal and sociodemographic risk factors on long-term morbidity within a total birth population in Florida.

METHODS

School records for 339 171 children entering kindergarten in Florida public schools in the 1992-1993, 1993-1994, or 1994-1995 academic years were matched with Florida birth records from 1985 to 1990. Effects on long-term morbidity were assessed through a multivariate analysis of an educational outcome variable, defined as placement into 9 mutually exclusive categories in kindergarten. Of those categories, 7 were special education (SE) classifications determined by statewide standardized eligibility criteria, 1 was academic problems, and the reference category was regular classroom. Generalized logistic regression was used to simultaneously estimate the odds of placement in SE and academic problems. The impact of all risk factors was assessed via estimated attributable excess/deficit numbers, based on the multivariate analysis.

RESULTS

Educational outcome was significantly influenced by both perinatal and sociodemographic factors. Perinatal factors had greater adverse effects on the most severe SE types, with birth weight <1000 g having the greatest effect. Sociodemographic predictors had greater effects on the mild educational disabilities. Because of their greater prevalence, the impact attributable to each of the factors (poverty, male gender, low maternal education, or non-white race) was between 5 and 10 times greater than that of low birth weight and >10 times greater than that of very low birth weight, presence of a congenital anomaly, or prenatal care.

CONCLUSIONS

Results are consistent with the hypothesis that adverse perinatal conditions result in severe educational disabilities, whereas less severe outcomes are influenced by sociodemographic factors. Overall, sociodemographic factors have a greater total impact on adverse educational outcomes than perinatal factors.

Educational disabilities of neonatal intensive care graduates

OBJECTIVE

To determine the relationship between perinatal and sociodemographic factors in low birth weight and sick infants hospitalized at regional neonatal intensive care units (NICUs) and subsequent educational disabilities.

METHOD

NICU graduates born between 1980 and 1987 at nine statewide regionalized level III centers were located in Florida elementary schools (kindergarten through third grade) during academic year 1992-1993 (n = 9943). Educational disability was operationalized as placement into eight mutually exclusive types of special education (SE) classifications determined by statewide standardized eligibility criteria: physically impaired, sensory impaired (SI), profoundly mentally handicapped, trainable mentally handicapped, educable mentally handicapped, specific learning disabilities, emotionally handicapped, and speech and language impaired (SLI). Logistic regression was used to estimate the odds of placement in SE for selected perinatal and sociodemographic variables.

RESULTS

Placement into SE ranged from .8% for SI to 9.9% for SLI. Placement was related to four perinatal factors (birth weight, transport, medical conditions [congenital anomalies, seizures or intraventricular hemorrhage] and ventilation), and five sociodemographic factors (child's sex, mother's marital status, mother's race, mother's educational level, and family income). Perinatal factors primarily were associated with placement in physically impaired, SI, profoundly mentally handicapped, and trainable mentally handicapped. Perinatal and sociodemographic factors both were associated with placement in educable mentally handicapped and specific learning disabilities whereas sociodemographic factors primarily were associated with placement in emotionally handicapped and SLI.

CONCLUSIONS

Educational disabilities of NICU graduates are influenced differently by perinatal and sociodemographic variables. Researchers must take into account both sets of these variables to ascertain the long-term risk of educational disability for NICU graduates. Birth weight alone should not be used to assess NICU morbidity outcomes.

Changing trend in perinatal management and outcome of extremely low birthweight (ELBW) infants

Perinatal care of the extremely preterm and low birthweight (ELBW) infant is founded on basic principles of physiology and knowledge about the prevailing pathophysiological mechanisms. New therapies in clinical care are usually introduced non-uniformly, so more often there is a gradual rather than a sudden change in the development of perinatal care, conceivably involving also an important learning process. This was confirmed in an evaluation of respiratory care for ELBW infants (n = 325) over a 9-year period (1986-1994). Although birthweight (mean 815 g) and degree of immaturity at birth (mean 26.7 weeks of gestation) did not change over the years, our trend analysis showed that the survival rate increased from 47% to 70% (p < 0.04) and the percentage of survivors without bronchopulmonary dysplasia and/or major intracranial haemorrhages (ICH grades 3 and 4) increased from 67% to 87% (p < 0.006). We suggest that besides medical treatment per se, refinement and tuning of nursing and medical care procedures will also affect the total outcome of ELBW infants.

Health and social characteristics and children's cognitive functioning: results from a national cohort

OBJECTIVES

The purpose of this study was to examine the associations between cognitive functioning in children and sociodemographic, family, and health characteristics.

METHODS

Data from phase 1 of the third National Health and Nutrition Examination Survey were used to evaluate performance on standardized cognitive tests in a representative sample of 2531 children 6 to 16 years of age. Multivariate analyses were used to assess independent associations between covariates and test performance.

RESULTS

Lower income, minority status, and lower education of an adult reference person (one of the persons in the household who owned or rented the home) were independently associated with poorer performance on all cognitive subtests. To a lesser degree, general health status, history of birth complications, and sex also were independent predictors of performance for some of the subtests.

CONCLUSIONS

These findings illustrate disparities in cognitive functioning across sociodemographic and health characteristics of children in the US population. They suggest the need for public health policies to take a multifaceted approach to optimizing childhood environments in order to overcome the effects of socioeconomic and minority status.

Infant neurodevelopmental outcome in pregnancies complicated by gestational hypertension and intra-uterine growth retardation

The neonatal outcome of 78 consecutive singleton pregnancies complicated by intrauterine growth retardation (IUGR) and gestational hypertension were compared with the outcome of 78 adequately matched pregnancies complicated by idiopathic IUGR. The rate of low (< 5) 1-minute Apgar scores was higher in infants born to hypertensive mothers (12.8% vs 2.6% p = .035). No differences in the prevalence of other perinatal factors such as acidosis, respiratory distress syndrome, hypoglycemia, pneumothorax, bronchopulmonary dysplasia, intracranial hemorrhage, requirement for assisted ventilation or survival were found between cases and controls. After two years' follow-up, the rate of major neurological neonatal handicaps, was 2.8% in the cases and 1.4% in the controls (p = 0.56). Mild neurodevelopmental abnormalities were more frequent in infants born to hypertensive mothers (14.3% vs 2.9% p = .025). After adjustment by multiple logistic regression, to eliminate the effect of confounding factors, the probability of normal neurodevelopmental outcome was reduced by 82% in infants born to hypertensive mothers as compared to controls (Odds Ratio = 0.18; 95% confidence interval 0.05 to 0.82 p = .028). These findings suggest that pregnancies complicated by IUGR and gestational hypertension are associated with a high prevalence of subsequent neurodevelopmental problems among infants.

A random coefficient growth curve analysis of mental development in low-birth-weight infants

In many medical studies, longitudinal data are collected on each of a sample of patients. The objectives of such studies often are: to estimate and test bivariate or multivariate relationships within each of several groups of patients from these repeated measures data; to compare these relationships among groups; and to test for the effects of baseline covariates on the relationships. This paper illustrates the use of statistical methods for growth curve analysis recently proposed by Vonesh and Carter for achieving these goals by relating a measure of preschool cognitive development to age in four race by sex groups of low-birth-weight infants. Significant declines in Bayley's Mental Development Index (MDI) with increasing age were found in all groups. Birth-weight did not significantly influence the rate of decline but did influence the overall level of performance. Even so, in the group most comparable to Bayley's normative population, predicted MDI was near the norm even for extremely low-birth-weight infants (that is, 1000 grams). Although there is some risk of mental deficit associated with prematurity, eventual developmental delays in low-birth-weight infants frequently are acquired with age. The rate of decline in MDI was significantly associated with race and mother's education. Assumptions required for the valid application of these methods are discussed and tested in the setting of this applied problem. The assumptions appeared valid in this application. We conclude with a brief discussion of available alternatives when the assumptions are violated and point to areas for future research.

Eight-year outcome in infants with birth weight of 500 to 999 grams: continuing regional study of 1979 and 1980 births. Victorian Infant Collaborative Study Group

The outcome at a mean age of 8.3 years was determined for 88 of 89 surviving children with birth weights of 500 to 999 gm who were born in Victoria in 1979 and 1980; the condition of the untraced child, severely disabled at 5 years of age, was assumed to be unchanged at 8 years. Principal impairments in the children at 8 years of age were cerebral palsy 8 (9%); bilateral blindness 6 (6.7%) and poor vision in another 4 (4.5%); bilateral deafness requiring amplification 5 (5.6%); and epilepsy 2 (2.2%). The Full Scale score of the Weschler Intelligence Scales for Children--Revised was available for 77 children: 5 scores (6.5%) were less than 71 (low IQ), and 9 (11.7%) were between 71 and 85 (borderline IQ). Severe disability in 16 children (18%) was due to severe cerebral palsy, bilateral blindness, or low IQ. Mild or moderate disability was present in another 18 children (20.2%) with borderline IQ, mild or moderate cerebral palsy, poor vision, deafness, or epilepsy. Significantly more outborn children (10/18, 55.6%) than inborn children (24/71, 33.8%) were disabled. Ten children required special schooling; reading accuracy or comprehension was at least 18 months behind chronologic age in 17 (23%) of 75 children in normal school who were tested. The 2-year assessment correctly estimated the category of disability at 8 years of age in 55 (62%), overestimated it in 24 (27%), and underestimated it in 10 (11%). For the 82 children also seen at 5 years age, the category of disability at 8 years of age was correctly identified in 69 children (84%), overestimated in 4 (5%), and underestimated in 9 (11%). Change in psychologic test scores was the principal reason for reclassifying children. We conclude that the 2-yar assessment was valuable in the early identification of most of the severely disabled children, but developmental delay at 2 years of age did not always portend intellectual impairment at 8 years of age.