Very low birthweight: behavioral sequelae at nine years of age

Prenatal exposure to a natural disaster and early development of psychiatric disorders during the preschool years: stress in pregnancy study

BACKGROUND

Growing evidence shows an association between in utero exposure to natural disasters and child behavioral problems, but we still know little about the development of specific psychopathology in preschool-aged children.

METHODS

Preschool children (n = 163, mean age = 3.19, 85.5% racial and ethnic minorities) and their parents (n = 151) were evaluated annually at ages 2-5 to assess the emergence of psychopathology using the Preschool Age Psychopathological Assessment (PAPA), a parent-report structured diagnostic interview developed for preschool-age children. Sixty-six (40.5%) children were exposed to Sandy Storm (SS) in utero and 97 (59.5%) were not. Survival analysis evaluated patterns of onset and estimated cumulative risks of psychopathology among exposed and unexposed children, in total and by sex. Analyses were controlled for the severity of objective and subjective SS-related stress, concurrent family stress, and demographic and psychosocial confounders, such as maternal age, race, SES, maternal substance use, and normative prenatal stress.

RESULTS

Exposure to SS in utero was associated with a substantial increase in depressive disorders (Hazard Ratio (HR) = 16.9, p = .030), anxiety disorders (HR = 5.1, p < .0001), and attention-deficit/disruptive behavioral disorders (HR = 3.4, p = .02). Diagnostic rates were elevated for generalized anxiety disorder (GAD; HR = 8.5, p = .004), attention-deficit/hyperactivity disorder (ADHD; HR = 5.5, p = .01), oppositional-defiant disorder (ODD; HR = 3.8, p = .05), and separation-anxiety disorder (SAD; HR = 3.5, p = .001). Males had distinctively elevated risks for attention-deficit/disruptive behavioral disorders (HR = 7.8, p = .02), including ADHD, CD, and ODD, whereas females had elevated risks for anxiety disorders (HR = 10.0, p < .0001), phobia (HR = 2.8, p = .02) and depressive disorders (HR = 30.0, p = .03), including SAD, GAD, and dysthymia.

CONCLUSIONS

The findings demonstrate that in utero exposure to a major weather-related disaster (SS) was associated with increased risk for psychopathology in children and provided evidence of distinct psychopathological outcomes as a function of sex. More attention is needed to understand specific parent, child, and environmental factors which account for this increased risk, and to develop mitigation strategies.

Mechanisms of Maternal Diet-Induced Obesity Affecting the Offspring Brain and Development of Affective Disorders

Depression and metabolic disease are common disorders that share a bidirectional relationship and continue to increase in prevalence. Maternal diet and maternal behaviour both profoundly influence the developmental trajectory of offspring during the perinatal period. At an epidemiological level, both maternal depression and obesity during pregnancy have been shown to increase the risk of neuropsychiatric disease in the subsequent generation. Considerable progress has been made to understand the mechanisms by which maternal obesity disrupts the developing offspring gut-brain axis, priming offspring for the development of affective disorders. This review outlines such mechanisms in detail, including altered maternal care, the maternal microbiome, inflammation, breast milk composition, and maternal and placental metabolites. Subsequently, offspring may be prone to developing gut-brain interaction disorders with concomitant changes to brain energy metabolism, neurotransmission, and behaviour, alongside gut dysbiosis. The gut microbiome may act as a key modifiable, and therefore treatable, feature of the relationship between maternal obesity and the offspring brain function. Further studies examining the relationship between maternal nutrition, the maternal microbiome and metabolites, and offspring neurodevelopment are warranted to identify novel therapeutic targets.

The Social Behaviour of 11- to 12-year-old Children Born as Low Birthweight and/or Premature Infants

Two studies (Study 1 and Study 2) were carried out to compare the social behaviour of school-aged children born as premature and/or low birthweight infants, with that of children born as healthy fullterm infants. Participants in Study 1 were 147 11-year-olds of whom 49 (29 females and 20 males) were reported by their parents to have been born prematurely. Participants in Study 2 were 84 11-year-old boys, 28 of whom were born with a birthweight less than 2000 grams. These at-risk subjects were followed for a period of two years. Subgroups within both study groups were matched with control groups using gender, age, and the school environment as common factors. Children in the target classes of Study 1 were classified using the Revised Class Play (Masten, Morison, & Pelligrini, 1985) and the Peer Nomination Inventory (Perry, Kusel, & Perry, 1988). In Study 2, the children completed the Pupil Evaluation Inventory (PEI) (Pekarik, Prinz, Liebert, Weintraub, & Neale, 1976). Findings suggest that aggressive behaviour is not related to birth status and that birth status is not linked to prosocial behaviour associated with sociability and likeability. However, both studies showed that children (boys and girls alike) born as premature or low birthweight infants, expressed greater levels of internalised social behaviour. These findings suggest that infants born premature and/or with a low birthweight may be less socially competent with their peers during their school-age years.

Frontal brain activation in premature infants' response to auditory stimuli in neonatal intensive care unit

The present study was focusing on the very few contacts with the mother's voice that NICU infants have in the womb as well as after birth, we examined whether they can discriminate between their mothers' utterances and those of female nurses in terms of the emotional bonding that is facilitated by prosodic utterances. Twenty-six premature infants were included in this study, and their cerebral blood flows were measured by near-infrared spectroscopy. They were exposed to auditory stimuli in the form of utterances made by their mothers and female nurses. A two (stimulus: mother and nurse) x two (recording site: right frontal area and left frontal area) analysis of variance (ANOVA) for these relative oxy-Hb values was conducted. The ANOVA showed a significant interaction between stimulus and recording site. The mother's and the nurse's voices were activated in the same way in the left frontal area, but showed different reactions in the right frontal area. We presume that the nurse's voice might become associated with pain and stress for premature infants. Our results showed that the premature infants reacted differently to the different voice stimuli. Therefore, we presume that both mothers' and nurses' voices represent positive stimuli for premature infants because both activate the frontal brain. Accordingly, we cannot explain our results only in terms of the state-dependent marker for infantile individual differences, but must also address the stressful trigger of nurses' voices for NICU infants.

Behavioral outcomes of extremely low birth weight children at age 8 years

OBJECTIVE

To describe the prevalence of behavioral problems and symptomatology suggestive of Autism and Asperger's disorders at age 8 years among extremely low birth weight (ELBW, <1 kg) children, born 1992 through 1995.

METHOD

Parent reports of the behavior of 219 ELBW (mean birth weight, 810 g; gestational age 26 weeks) were compared with 176 normal birth weight children of similar maternal sociodemographic status, sex, and age. Behavior was assessed via the Child Symptom Inventory that includes both Symptom Severity Scores and scores meeting DSM-IV criteria for disorders.

RESULTS

ELBW compared with normal birth weight children had significantly higher mean Symptom Severity Scores for the inattentive, hyperactive, and combined types of attention-deficit hyperactivity disorder (all p < .001) as well as higher scores for Generalized Anxiety (p < .01) and Autistic (p < .001) and Asperger's (p < .01) disorders. When DSM-IV criteria were considered, ELBW children also had significantly higher rates of attention-deficit hyperactivity disorder of the inattentive (10% vs 3%, p < .01) and combined (5% vs 0.6%, p < .05) types.

CONCLUSIONS

Attention-deficit hyperactivity disorder, mainly the inattentive type is prevalent among ELBW children. Our findings of an increase in symptoms pertaining to Autistic and Asperger's disorders at school age agree with recent reports of others during early childhood. Early identification and intervention for these problems might improve child functioning and ameliorate parent and child distress.

Prediction of behavior problems in 4-year-olds born prematurely

Longitudinal follow-up data for 69 very low birthweight preterm infants were used to assess the influence of four factors (neonatal medical complications, infant temperament, mother-child relationships, and family environment) on mother and teacher reports of behavior problems at 4 years. The proposed model of such influences being tested assumed that (1) the effects of neonatal medical factors would be indirect, and (2) each of the other three factors would show high stability from 1 to 4 years and would have a direct influence on behavior problem outcomes. Neither neonatal medical data nor infant-mother attachment were good predictors of behavior problems at age 4. With these exceptions, teacher report of behavior problems was predicted in a fashion consistent with the preliminary model. However, mother reports of behavior problems was predicted only by prior mother reports of child temperament. Discussion focuses on reasons for discrepancies in these pathways of influence.

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.

Behavior problems at 3 and 6 years: Prevalence and continuity in full-terms and preterms

Results are reported for a 3-year prospective longitudinal study of behavior problems in a group of children born at very low birthweight (<1,500 g) and a full-term control. Behavior problems were assessed with the Behavior Screening Questionnaire (BSQ) at 3 years and with the Child Behavior Checklist (CBCL) and the hyperactivity index from the Conners parent and teacher scales at 6 years. The findings indicate that the preterms manifested more behavior problems than full-terms at both ages and that the overall prevalence of clinically significant problems increased with age. Although cross-age continuity on parent rating scales was similar and modest for both groups (r = .24–.35), the persistence of significant problems was quite high (50%). Early BSQ scores predicted later externalizing problems, even after the effects of prematurity, socioeconomic status, and family stress were removed, but not later internalizing problems. The latter were more strongly influenced by low SES and family stress. Findings for the full-terms, who had received the CBCL as well as the BSQ at 3 years, suggest that these two instruments may tap somewhat different dimensions of behavior disturbance at age 3.

Weight concerns in male low birth weight adolescents: relation to body mass index, self-esteem, and depression

OBJECTIVE

To compare weight concerns and self-reported body mass index (BMI) of low birth weight (LBW) adolescent boys to those of a normative sample and examine relationships among BMI, weight concerns, self-esteem, and depression in the LBW cohort.

METHODS

LBW boys (n = 260; mean age, 16.0) belong to the Neonatal Brain Hemorrhage Study birth cohort. Normative boys (n = 305; mean age, 16.5) belong to the National Health and Nutrition Examination Survey. Both samples were assessed in 2001-2004 with self-report questionnaires. BMI was calculated from self-reported height and weight. Weight perception and weight dissatisfaction were assessed with the Eating Symptoms Inventory. In LBW boys, self-esteem was measured with the Rosenberg Self-Esteem Scale and depression with the Beck Depression Inventory.

RESULTS

Based on self-reported height and weight, LBW boys were more likely to be healthy weight or underweight and less likely to be overweight than normative boys. Despite having healthier self-reported BMIs, LBW boys reported more weight concerns than the normative sample. A total of 46.9% of LBW boys perceived their weight as abnormal, and 76.5% desired weight change. Weight concerns in LBW boys mostly reflected a perception of being underweight (31.2% of the cohort) and a desire to gain weight (47.5% of the cohort), although only 6.5% were clinically underweight. Weight concerns, but not BMI, were related to clinical depression and lower self-esteem.

CONCLUSIONS

LBW adolescent boys are at high risk of experiencing weight concerns. Weight concerns rather than BMI are associated with emotional problems in LBW boys.

Behavioral outcomes and evidence of psychopathology among very low birth weight infants at age 20 years

OBJECTIVE

Information on the mental health of very low birth weight (VLBW; <1500 g) children in young adulthood is sparse. We thus sought to examine gender-specific behavioral outcomes and evidence of psychopathology in a cohort of VLBW young adults at 20 years of age.

METHODS

We compared a cohort of 241 survivors among VLBW infants who were born between 1977 and 1979 (mean birth weight: 1180 g; mean gestational age at birth: 29.7 weeks), 116 of whom were men and 125 of whom were women, with 233 control subjects from the same population in Cleveland who had normal birth weights (108 men and 124 women). Young adult behavior was assessed at 20 years of age with the Achenbach Young Adult Self-Report and the Young Adult Behavior Checklist for parents. In addition, the young adults and parents completed the ADHD Rating Scale for Adults. Gender-specific outcomes were adjusted for sociodemographic status.

RESULTS

VLBW men reported having significantly fewer delinquent behaviors than normal birth weight (NBW) control subjects, but there were no differences on the Internalizing, Externalizing, or Total Problem Behavior scales. Parents of VLBW men reported significantly more thought problems for their sons than did parents of control subjects. VLBW women reported significantly more withdrawn behaviors and fewer delinquent behavior problems than control subjects. Their rates of internalizing behaviors (which includes anxious/depressed and withdrawn behaviors) above the borderline clinical cutoff were 30% versus 16% (odds ratio: 2.2; 95% confidence interval [CI]: 1.2-4.1). Parents of VLBW women reported significantly higher scores for their daughters on the anxious/depressed, withdrawn, and attention problem subscales compared with control parents. The odds ratios for parent-reported rates above the borderline-clinical cutoff among women for the anxious/depressed subscale was 4.4 (95% CI: 1.4-13.5), for thought problems was 3.7 (95% CI: 1.2-11.6), and for attention problems was 2.4 (95% CI: 1.0-5.5). There were no differences in the young adult self-report of attention-deficit/hyperactivity disorder (ADHD). Parents of VLBW men reported higher mean scores on the attention subtype of ADHD but not higher rates of ADHD.

CONCLUSION

The increase in psychopathology among VLBW survivors in young adulthood indicates a need for anticipatory guidance and early intervention that might help to prevent or ameliorate potential psychopathology.

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

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

Does Maternal Warmth Moderate the Effects of Birth Weight on Twins' Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms and Low IQ?

The moderating effect of maternal warmth on the association between low birth weight and children's attention-deficit/hyperactivity disorder (ADHD) symptoms and low IQ was studied in 2,232 twins. Half of 5-year-old children had low birth weights, below 2,500 g. Maternal warmth, a component of expressed emotion, was coded from mothers' audiotaped descriptions of each child. Both parents and teachers rated children's ADHD symptoms, and the children were administered an IQ test. Results showed a significant interaction between children's birth weight and maternal warmth in predicting mothers' and teachers' ratings of ADHD. The interaction was not significant for IQ. The findings suggest that the effect of children's birth weight on their ADHD symptoms can be moderated by maternal warmth and that enhancing maternal warmth may prevent behavior problems among the increasing population of low-birth- weight children.

Special education services and school performance in a regional cohort of low-birthweight infants at age nine

Previous research has shown that low birthweight is a predictor of several adverse educational outcomes, including special educational placement, by middle school age. Most low-birthweight follow-up studies that have extended to school age have focused on very small infants-- < 1500 or < 1000 g; less is known of the school age outcomes for infants with only moderately low birthweight (1500-2000 g). This study examines the prevalence of special educational placement and the relationship of such placement to grade retention, verbal and performance scores on tests of general intelligence, reading and maths achievement scores and classroom hyperactivity among low-birthweight children. In a regional birth cohort of 1105 infants born between 1984 and 1987 and weighing 500-2000 g, 868 children were available for follow-up at age nine. Information on special education placement as well as grade retention, intelligence, academic achievement and classroom behaviour was available on 645 (74% completion rate). Nearly a third of the cohort was classified as needing special education. Special education placement followed a birthweight gradient, occurring among 29.3% of children with birthweights 1500-2000 g, among 32.5% in children 1000-1500 g and 49.4% in children < 1000 g. Among children in special education, a similar birthweight gradient was found for maths achievement and hyperactivity, but not for reading achievement or IQ scores. Among children not in special education, only maths achievement showed such a decline with birthweight. A substantial proportion of low-birthweight children, including those of moderate low birthweight, receive special education services, although the need is greatest among those with the lowest birthweights. Maths achievement declined with birthweight regardless of educational placement. The medical and social risk factors that accompany low birthweight and may account for these findings, require further study.

Aspects of inattention in low birth weight children

The objective of this study was to explore the nature of impaired attention in low birth weight children. A population-based sample (n = 129) of 11-year-old low birth weight children was compared with a randomized group of normal birth weight children (n = 128). Continuous Performance Test, a Cue-Target Task, and a Stroop Color-Word test were used to assess the following dimensions of attentional function: inattention, impulsivity, vigilance, selected attention, and alternating attention. The attention subscale from the Child Behavior Check List questionnaire was included to assess maternal report of inattention. Low birth weight children had generally slower reaction time than normal birth weight children and manifested impaired vigilance, but this could be attributed to group differences in confounding parental factors. Impairment was not a function of birth weight within the low birth weight group, but low birth weight boys manifested impaired vigilance compared with normal birth weight boys. Every fourth low birth weight child was reported with inattention, but small differences were found between the inattentive and attentive low birth weight children. No specific attentional dysfunction was observed in the low birth weight study group. The nature of reported impaired attention among low birth weight children is still uncertain.

Birth weight and later risk of depression in a national birth cohort

BACKGROUND

Low birth weight increases the risk of childhood behavioural problems, but it is not clear whether poor foetal growth has a long-term influence on susceptibility to depression.

AIMS

To examine the relation between birth weight and risk of psychological distress and depression.

METHOD

At age 16 years 5187 participants in the 1970 British Cohort Study completed the 12-item General Health Questionnaire to assess psychological distress. At age 26 years 8292 participants completed the Malaise Inventory to assess depression and provided information about a history of depression.

RESULTS

Women whose birth weight was </=3 kg had an increased risk of depression at age 26 years (OR=1.3; 95% CI1.0-1.5) compared with those who weighed >3.5 kg. Birth weight was not associated with a reported history of depression or with risk of psychological distress at age 16 years. In men there were no associations between any measurement and the full range of birth weight but, compared with men of normal birth weight, those born weighing </=2.5 kg were more likely to be psychologically distressed at age 16 years (OR=1.6,95% CI1.1-2.5) and to report a history of depression at age 26 years (OR=1.6,95% CI1.1-2.3).

CONCLUSIONS

Impaired neurodevelopment during foetal life may increase susceptibility to depression.

Neonatal behavioral characteristics and later behavioral problems

The purposes of this study were (1) to evaluate the usefulness of the Neonatal Behavioral Assessment Scale (NBAS) as a tool to assess the risk of later behavioral problems, (2) to analyze the relationship between neonatal behavioral characteristics and behavioral problems in childhood. Subjects were 77 very-low-birth-weight infants admitted to the NICU at the Nagasaki University Hospital, Nagasaki, Japan. The results suggest that behavioral characteristics such as poor motor performance, poor state regulation, and poor interaction ability in the neonatal period are risk factors for behavioral problems in childhood. The NBAS could help clinicians to identify neonates at risk of later behavioral problems.

Psychopathology and social competencies of adolescents who were extremely low birth weight

BACKGROUND

We have previously shown that infants who were extremely low birth weight (ELBW) are particularly vulnerable to problems related to inattention and hyperactivity at school age. It is not known whether these problems persist to adolescence.

OBJECTIVE

To explore and compare the levels of psychopathology in a regional cohort of ELBW infants and sociodemographically matched term controls as reported by teens and their parents.

DESIGN/METHODS

Cross-sectional cohort study/geographically defined region.

PARTICIPANTS

TEENS: ELBW 141/169 (83%) and control 122/145 (84%), aged 12 to 16 years. PARENTS: ELBW 143/169 (85%) and control 123/145 (85%). Both cohorts and their parents completed the Ontario Child Health Study-Revised questionnaire with 6 behavioral subsca1es: conduct disorder, oppositional defiant disorder, attention-deficit/hyperactivity disorder (ADHD), overanxious, separation anxiety, and depression.

RESULTS

By teen self-report, there were no significant differences between ELBW and control teens on any of the 6 subscale scores. However, parents of ELBW teens reported significantly higher scores than parents of control for depression and ADHD based on 2-way analysis of variance (group x gender). Comparison within teen/parent dyads showed that both cohorts of teens reported significantly higher scores than their parents. Multivariable analyses on behavioral subscale scores demonstrated a number of variables that were significant predictors by parent report: group (ELBW vs control), gender, family function, developmental quotient, maternal mood, and socioeconomic status; no predictors were significant by teen report. There were no statistically significant interaction effects for any of the models. These models explained a greater percent of the variance in behavioral scores for parents than for teens (12.5%-22.0% vs 3.4%-8.2%). Results were similar when teens with neurosensory impairment were excluded.

CONCLUSIONS

This study is unique in the inclusion of both parent and teen self-report of behaviors. Significant differences were apparent only by parent report for ADHD and depression among ELBW teens. Significant predictors of behavioral scores for parents include group, gender, family function, developmental quotient, maternal mood, and socioeconomic status.

Maternal perinatal events as predictors of educational placement: computation of relative risk ratios

This study examined the relative risk of perinatal complications in special education. The sample consisted of 634 children (normal children and those with mental retardation, learning disabilities, and emotional handicaps) whose mothers completed the Maternal Perinatal Scale (MPS). Seven MPS items significantly contributed to the prediction of the mentally retarded, learning disabled, emotionally handicapped, and regular education groups. The two significant discriminant functions correctly classified some 46% of the students correctly. When the separate disorders were collapsed to form a single group, 11 MPS items significantly contributed to the prediction of the special education and regular education groups. The linear composite from discriminant function analysis (DFA) correctly classified some 89% of the special education students. When MPS items were used as predictors, 90% of the special education students were correctly classified. Seven MPS factors comprised the discriminant function. Relative risk ratios were computed for each perinatal item. An overall relative risk of 6.35 resulted, based on the linear composite of perinatal variables defined by the discriminant function, suggesting that a synergism of perinatal complications makes a child over 6 times more likely to be placed in special education. A second overall relative risk of 3.83 was derived from the linear composite of MPS items. This indicated that children with a perinatal history marked by this particular combination of perinatal complications were nearly 4 times as likely to require special educational services.

Impact of low birth weight on attention-deficit hyperactivity disorder

The objective of the study was to evaluate an association between low birth weight (LBW) and attention-deficit hyperactivity disorder (ADHD) attending to potential family-genetic and environmental confounders. We examined 252 ADHD cases (boys and girls) and 231 non-ADHD controls and their parents. All subjects were extensively assessed with structured diagnostic interviews, cognitive assessments, and structured interviews of prenatal, infancy, and delivery complications. ADHD cases were three times more likely to have been born LBW than were non-ADHD controls, after attending to potential confounders such as prenatal exposure to alcohol and cigarettes, parental ADHD, social class, and comorbid disruptive behavior disorders in parents and offspring. If this association was causal, 13.8% of all ADHD cases could be attributed to LBW. These results converge with prior studies documenting similar associations and indicate that LBW is an independent risk factor for ADHD. Children with LBW, however, make up a relatively small proportion of children with ADHD.

Behavioural problems in children who weigh 1000 g or less at birth in four countries

BACKGROUND

The increased survival chances of extremely low-birthweight (ELBW) infants (weighing <1000 g at birth) has led to concern about their behavioural outcome in childhood. In reports from several countries with different assessments at various ages, investigators have noted a higher frequency of behavioural problems in such infants, but cross-cultural comparisons are lacking. Our aim was to compare behavioural problems in ELBW children of similar ages from four countries.

METHODS

We prospectively studied 408 ELBW children aged 8-10 years, whose parents completed the child behaviour checklist. The children came from the Netherlands, Germany, Canada, and USA. The checklist provides a total problem score consisting of eight narrow-band scales. Of these, two (aggressive and delinquent behaviour) give a broad-band externalising score, three (anxious, somatic, and withdrawn behaviour) give a broad-band internalising score, and three (social, thought, and attention problems) indicate difficulties fitting neither broad-band dimension. For each cohort we analysed scores in ELBW children and those in normal- birthweight controls (two cohorts) or national normative controls (two cohorts). Across countries, we assessed deviations of the ELBW children from normative or control groups.

FINDINGS

ELBW children had higher total problem scores than normative or control children, but this increase was only significant in European countries. Narrow-band scores were raised only for the social, thought, and attention difficulty scales, which were 0.5-1.2 SD higher in ELBW children than in others. Except for the increase in internalising scores recorded for one cohort, ELBW children did not differ from normative or control children on internalising or externalising scales.

INTERPRETATION

Despite cultural differences, types of behavioural problems seen in ELBW children were very similar in the four countries. This finding suggests that biological mechanisms contribute to behavioural problems of ELBW children.

School-age consequences of birth weight less than 750 g: a review and update

Recent advances in perinatal care have led to the survival of increasing numbers of children born at the lower limits of viability. Children with very low birth weight (LBW; less than 1,500 g, 3 lb 5 oz) have been studied extensively. Findings document poorer outcomes relative to normal birth weight term-born controls in neurologic and health status, cognitive-neuropsychological skills, school performance, academic achievement, and behavior. This report reviews current knowledge regarding LBW children, with special emphasis on outcomes for children with birth weight less than 750 g (1 lb 10 oz). Results from an ongoing longitudinal study suggest a gradient of sequelae, with poorer outcomes in less than 750 g birth weight children compared to both 750 g to 1,499 g birth weight children and term-born controls. Children with less than 750 g birth weight fail to catch up with their peers over time and may even be at risk for age-related increases in sequelae. Outcomes are highly variable but related to neonatal medical complications of prematurity and social risk factors. Further research is needed to understand the etiology and neuropathological basis of sequelae, the long-term developmental implications of LBW, and treatment needs.

Birthweight and behavioural problems in children: a modifiable effect?

BACKGROUND

Low birthweight has been shown to predict behavioural problems in children. Less is known about the effect of birthweight, and how this may interact with the social environment in determining behaviour in a general population sample. We have examined the relationship between birthweight and social factors on childhood psychological well-being.

METHODS

Cross-sectional analysis of data on 5181 children aged 4-15 years from a randomly selected household population, the 1997 Health Survey for England. The main outcome measures were behavioural problems as defined by the Strengths and Difficulties Questionnaire (SDQ) in relation to birthweight and social environmental factors.

RESULTS

Birthweight was a significant predictor of total difficulties score (odds ratio [OR] = 1.27, 95% CI : 1.07, 1.49), hyperactivity in boys (OR = 1.25, 95% CI : 1.05, 1.51), and peer problems in girls (OR = 1.24, 95% CI : 0.99, 1.53). There was a strong social class gradient in the prevalence of behavioural problems for all birthweight tertiles. Bivariate analysis showed that high total difficulties score was significantly more common in lower birthweight tertiles for social classes III non-manual and III manual (P:-value for trend 0.05 and 0.03, respectively). There were smaller, non-significant effects of birthweight on the prevalence of behavioural problems in social class I and II, and IV and V. Statistical tests for an interaction between birthweight and social class were not significant.

CONCLUSIONS

Early life factors, such as birthweight and social class have important influences on psychological well-being in children. The birthweight effect is influenced by social factors, with the possibility that an advantaged social environment protects against the development of behavioural problems, and a disadvantaged environment increases the risk of behavioural problems, regardless of birthweight.

Behavioral sequelae of perinatal insults and early family adversity at 8 years of age

OBJECTIVE

This prospective longitudinal study investigated the simultaneous impact of early biological and psychosocial risk factors on behavioral outcome at school age.

METHOD

A cohort of 362 children born between 1986 and 1988 with different biological (perinatal insults) and psychosocial risk factors (family adversity) was followed from birth to school age. When their children were aged 8 years, parents of 89.0% of the initial sample completed the Child Behavior Checklist (CBCL).

RESULTS

More externalizing as well as internalizing problems were found in children born into adverse family backgrounds, whereas no differences at broad-band syndrome level were apparent between groups with varying obstetric complications. Children with family risk factors had higher scores on 5 of the 8 CBCL scales (including attention, delinquent, and aggressive problems), whereas children with perinatal risk factors had more social and attention problems than children in the nonrisk groups. With one exception, no interactions between risk factors emerged, indicating that perinatal and family risk factors contributed independently to outcome. The differences between risk groups applied irrespective of gender.

CONCLUSIONS

The adverse impact of family adversity clearly outweighed the influence of obstetric complications in determining behavioral adjustment at school age.

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.

School difficulties at adolescence in a regional cohort of children who were extremely low birth weight

OBJECTIVES

To compare measures of psychometric assessment and school difficulties in a cohort of extremely low birth weight (ELBW) teenagers and term controls, and to determine whether there is stability in psychometric measures between age 8 and the teen years.

STUDY DESIGN

Longitudinal follow-up; geographically defined region.

PARTICIPANTS

150 of 169 (89%) ELBW survivors born between 1977 and 1982 and 124 of 145 (86%) sociodemographically matched term controls between 12 and 16 years of age. Psychometric measures: Wechsler Intelligence Scale for Children-Revised, Wide Range Achievement Test-Revised, and a validated parent questionnaire.

RESULTS

Neurosensory impairments were present in 28% of ELBW and 1% of controls. The mean Wechsler Intelligence Scale for Children-Revised scores were ELBW: 89 +/- 19 and controls: 102 +/- 13. ELBW children did less well on Wide Range Achievement Test-Revised Reading, Spelling, and Arithmetic measures with mean scores in the range from 75 to 85. ELBW children <750 g were more disadvantaged, compared with those >/=750 g. A significantly higher proportion of ELBW children were receiving special educational assistance and/or had repeated a grade (ELBW: 58%; controls: 13%; odds ratio: 9.0). Paired analysis of within-cohort data at age 8 and teen years showed that for both cohorts Arithmetic scores declined, but there were small improvements in other measures, predominantly in the term children.

CONCLUSIONS

Differences of 13 to 18 points in psychometric measures in ELBW teens compared with controls are both statistically significant and clinically relevant. Decreasing birth weight was associated with increased risk on all measures. The high utilization of special educational resources has economic implications, and the incremental cost attributable to being extremely premature needs to be determined.

Neurologic soft signs and low birthweight: their association and neuropsychiatric implications

BACKGROUND

We examine the relationship between neurologic soft signs and cognitive deficits, learning disorders, and psychiatric problems in low birthweight (LBW) and normal birthweight (NBW) children.

METHODS

Representative samples of LBW and NBW children were selected from the 1983-1985 newborn discharges of two major hospitals in Michigan. Eight hundred-twenty three children (75% of the target sample) were evaluated at ages 6 and 11. A standardized neurologic evaluation was used by neurologists to measure neurologic soft signs at age 6 (children with frank neurologic impairment were excluded). IQ was measured by WISC-R and behavior problem lists were rated by mothers and teachers. Standard tests of academic achievement were used to identify learning disorders. All assessments were blind to LBW status. Using multiple regression analysis, applying generalized estimating equations (GEE), we estimated the effects of soft signs on 3 behavioral domains, based on information from multiple informants and times of assessment.

RESULTS

LBW was associated with a two-fold increased risk for soft signs. Soft signs increased the risk for subnormal IQ and for learning disorders in children with normal IQ. Soft signs were associated with excess internalizing problems in LBW and NBW children, and with attention and externalizing problems in LBW children; the excess in externalizing problems in LBW children was observed only at age 6.

CONCLUSIONS

Soft signs are a marker of high risk for cognitive and psychiatric problems. Of particular concern is their presence in LBW children, in whom they are associated with more severe cognitive deficits and more pervasive psychiatric problems.

Medical and ecological factors in estimating motor outcomes of preschool children

The twofold purpose of this study was to compare motor function in preschool children born with varying degrees of medical risk and to determine the independent contribution to motor function of three domains of ecological influence. One hundred and eighty-four 4-year-old children and their mothers participated. Three predictor sets, proximal, distal, and child, and four motor outcomes were measured by multiple methods. Children born prematurely scored lower on all dimensions of motor function. Prematurity complications had a different effect on motor function. Hierarchical regression models explained 16-40% of motor score variance. Results are discussed in relation to heterogeneity of prematurity and ecological influences on motor outcomes.

Association of maternal, antenatal and perinatal complications with suicide in adolescence and young adulthood

The aim of the present study was to investigate whether maternal, antenatal and perinatal complications are associated with adolescent or young adulthood suicide in offspring. Cases consisted of individuals, aged 15-22 years, born in New York City and committing suicide in New York City between 1985 and 1991 (n = 189). Two controls were selected for each case, constituting the hospital birth immediately preceding and following that of the case, matched with the case with regard to sex and ethnicity. Cases were compared with controls using an index that summed a range of maternal, antenatal and perinatal complications and also with regard to the frequency of individual complications. In the total sample, cases and controls did not differ either in the mean number of all complications combined or in the proportions with specific complications. This lack of association between complications and outcome also obtained in separate analyses by sex, ethnicity, socio-economic status and age at suicide. These results fail to replicate the findings of two previous reports implicating maternal, antenatal and perinatal complications in risk of youth suicide. At present, epidemiological evidence that adverse reproductive events increase the risk for suicide in offspring remains inconclusive.

Acute-phase neurologic complications of Haemophilus influenzae type b meningitis: association with developmental problems at school age

The purposes of this study were to describe the incidence of acute-phase neurologic complications in a sample of 126 children with Haemophilus influenzae type b meningitis, and to determine if these complications were associated with higher rates of learning and behavior problems at school age. Risks were assessed by comparing rates of adverse psychoeducational outcomes in the 53 children in the sample with complications to corresponding outcome rates in the 67 children who were free of neurologic complications and who did not have abnormal electroencephalograms (EEGs) or computed tomographic (CT) scans. Comparisons were made by means of logistic regression analysis. Twenty-nine children (23% of the sample) had seizures, 16 (13%) were comatose or obtunded, 15 (12%) had sensorineural hearing loss, 8 (6%) had hemiparesis, and 7 (6%) had cranial nerve deficits other than hearing loss. Relative to children without complications, those with complications had higher rates of grade repetition and substandard performance on neuropsychological and achievement testing. Adverse outcomes, however, consisted primarily of more subtle cognitive and learning problems; only two of the children in the sample obtained prorated IQ scores below 70. Sequelae were associated with persistent neurologic deficits and bilateral hearing loss, as well as with transient symptoms including seizures, coma, and hemiparesis. While study findings argue against adverse consequences for the vast majority of children treated for this disease, the results clarify learning and behavior outcomes and indicate which children are at greatest risk.

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.

Behavioral effects of prematurity

This report reviews the evidence for an increased incidence of behavior and social problems in infants and children born prematurely. The contribution of biological and social factors to the development of behavior problems in this population is also examined. The available evidence indicates that preterms more often than full-terms exhibit negative temperament characteristics, symptoms of Attention-Deficit Hyperactivity Disorder, and lower levels of social competence. The risk for these problems appears to be limited to those infants with a birth weight of less than 1,500 g. Adverse social conditions also impact the expression of these problems. Preterms do not appear to be at as much risk for emotional or conduct problems or abnormal attachment to their mothers. Both the experience of a preterm birth and the characteristics of the infant can alter the perceptions and behavior of parents. Appropriate interventions should involve the child, the parents, and the school.

Effects of medical risk and socioeconomic status on the rate of change in cognitive and social development for low birth weight children

Using Hierarchical Linear Models (HLM) analysis, this study evaluated the effects of medical risk at birth and socioeconomic status (SES) on the rate of change in cognitive and social development over the first three years of life in premature children with low birth weight (LBW). Children with LBW (n = 79) with both high (HR) (n = 37) and low (LR) (n = 42) medical risk were compared to healthy full-term (FT) (n = 49) children. Children were assessed longitudinally at 6, 12, 24, and 36 months for cognitive development with the Bayley Scales of Infant Development and the McCarthy Scales for Children's Abilities, and for social initiative and responsiveness with observational measures. The HR LBW group had slower rates of increases in cognitive scores than did the LR LBW and FT groups and showed more deceleration in cognitive development by 36 months of age. Children with LBW, regardless of medical risk, had lower social initiating scores and slower rates of increase in initiating across the first 36 months than did FT children. As predicted, the groups did not show different rates of change for measures of social responsiveness. Higher SES was predictive of better cognitive and social development for all children. The difficulties encountered by children with LR and HR LBW in developing social initiating skills are discussed in relation to the link between learning to take initiative and early executive function skills.

Behavioural adjustment in school of very low birthweight children

The school-based behavioural adjustment at 7-8 years of a cohort of 243 prematurely born, very low birthweight (< 1501 g) children and their normal birthweight controls is reported. The findings indicate that the children born preterm (both male and female) were rated by their teachers as expressing more behaviour problems than their controls, and were less well adjusted to the school environment. The deficits noted in the preterms applied across the social classes, with no amelioration noted in preterms of higher social class. It is speculated that the problem behaviours reflect a failure in self-regulatory functions.

School performance of ELBW children: a controlled study

This paper examines the prevalence of learning difficulty in reading, spelling, mathematics and writing and the prevalence of attention deficit disorder (ADD) in extremely low-birthweight (ELBW) children at school compared to their peers. Parents of 87 eligible ELBW children completed an educational questionnaire and questionnaire for ADD. Teachers of the ELBW children completed a detailed educational and ADD questionnaire for the study child and two control children in the same class, matched for age and nearest in birth date to the study child. Parents reported that 4% of the ELBW children born between 1977 and 1986 were in a special education unit, 46% received remedial help and 21% repeated a grade. Teacher assessment of six aspects of reading and spelling and five aspects of mathematics and writing skills indicated that the ELBW children experienced marked problems in all areas compared to control children and were approximately 3 times more likely to be delayed by more than a year in all areas. Prevalence of ADD was not increased in the ELBW children compared to the control group, though males in both groups had a higher prevalence of symptoms. Early intervention and special education resources must be available for ELBW children attending school.

Behavioral problems in low-birthweight preschoolers

Preschool behavior of a population-based sample of 144 5-year-old children with birthweights less than 2000g (LBW) was compared with a random sample of 163 normal-birthweight term controls. The Personality Inventory for Children and the Yale Children's Inventory were completed by the mothers, and child behavior during psychometric testing was assessed. Nineteen per cent of the LBW children compared to 4% of controls had behavioral problems as defined by abnormal scores on more than three behavioral measures. The LBW children were more often socially insecure, anxious and difficult to manage, but inattention and hyperactivity were not prominent. The LBW children were not more sensitive to the negative impact of parental risk factors than normal-birthweight children.

Low birth weight and neurocognitive status at six years of age

We examined the relationship between low birth weight (LBW) (< or = 2500 g) and specific neurocognitive abilities at 6 years of age in a large-scale nonconcurrent prospective study. In 1990-1992, we randomly selected and evaluated LBW and normal birth weight (NBW) children from the 1983-1985 newborn lists of two major hospitals in southeast Michigan, one serving an urban and the other a suburban population. LBW children (n = 473) scored significantly lower than NBW children (n = 350) on tests measuring language, spatial, fine motor, tactile, and attention abilities, controlling for population site, race, maternal IQ, and education. Gradient relationships were observed across levels of LBW with language, spatial, tactile, and attention tests. Exploratory analysis, using general additive models, revealed that test performance varied within birth weight levels and that performance continued to improve with increased birth weight well above 3000 g. Follow-up assessments as the children mature will shed light on the persistence of these associations and their implications for learning disorders.

Twin sibling differences in parental reports of ADHD, speech, reading and behaviour problems

Differences between twins and siblings in behaviour problems were investigated in a non-selected sample of 1938 families with children aged 4-12 years. Families were sent a questionnaire based on DSM-III-R criteria for Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), Conduct Disorder (CD) and Separation Anxiety (SA), which was validated by formal clinical interview. The questionnaire also included measures of speech and reading problems. There were significant differences between twins and siblings for ADHD symptoms, but not for symptoms of ODD, CD or SA. Twins and siblings differed significantly for gestational age, birth weight, speech and reading problems. While there was little evidence for birth weight or gestational age contributing to the difference in ADHD symptoms, there was a strong association between ADHD symptoms and speech and reading problems.

Genetic influence on parent-reported attention-related problems in a Norwegian general population twin sample

OBJECTIVE

To assess the genetic and environmental influences on attention problems in a general population twin sample and to investigate whether there are changes in the relative genetic influence on attention problems with increasing severity.

METHOD

Parental ratings of the Child Behavior Checklist were collected from five Norwegian national cohorts of same-sex twins. The sample comprises 526 identical and 389 fraternal pairs.

RESULTS

Considerable genetic influence on attention problems was found for both sexes and across age groups (aged 5 to 9 years and 12 to 15 years). A two-parameter model with additive genetic influence and nonshared environment showed a good fit, with heritability ranging from .73 in boys aged 5 to 9 years, to .76 in girls aged 5 to 9 years. There was no change in the relative genetic influence across severity after accounting for the influence of cerebral palsy, epilepsy, and low birth weight.

CONCLUSION

The results indicate a substantial genetic influence on attention problems across sex, age, and severity.

Long-term behavioral sequelae of prematurity

OBJECTIVE

Longitudinal evaluation of the competence and the prevalence of behavior problems in preterm children with serious neonatal complications.

METHOD

Prospective follow-up of nonhandicapped preterm children who had been hospitalized in a neonatal intensive care unit (n = 177). The follow-up extended from early school age to early adolescence and was conducted with the help of the Child Behavior Checklist (CBCL) (parent form).

RESULTS

The preterm children had lower scores on the Social and School Competence scales than did controls (n = 276). They also were more likely to attend special schools than were children in the general population. With regard to behavior problems, the preterm children had more social problems. The very preterm children and the children who were small for gestational age (SGA) were the ones who contributed to the significant findings. The children who were appropriate for gestational age did not differ from controls. No differential changes in CBCL ratings were found between the preterm and control children. The stability with regard to internalizing problems, attention problems, and social problems was high among the very preterm children and SGA children.

CONCLUSION

Very preterm and preterm SGA children are at increased risk of problems in social functioning and functioning at school. These problems persist with age.

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.

Parental ratings of behaviour problems: a twin and general population comparison

Generalization from twin studies relies on the assumption that liability to develop the disorder which is studied is influenced by similar factors in twins and singletons. The present study examines the impact of pre- and perinatal factors on parental reports of behaviour problems in 1832 twins, and compares level of attention problems, internalizing and externalizing behaviour in the twins with 723 children and adolescents from a general population sample. The modest influence of relative birth weight and birth order on level of attention problems in twins did not contribute to significant differences between twins and the general population sample. The levels of attention problems and externalizing behaviour was similar and there was a modest age dependent difference in internalizing behaviour. An increased variance was found for externalizing behaviour in twins.