Neonatal hyperbilirubinemia at high altitude

A previous retrospective study showed an increased frequency of neonatal hyperbilirubinemia at high altitude in Colorado. In a prospective study we found that 39% of newborns at 3100 m altitude vs 16% at 1600 m exhibited hyperbilirubinemia, defined as a day 3 serum bilirubin level of 205 mumol/L or higher. Increased bilirubin production at 3100 m vs 1600 m was shown by increased levels of corrected carboxyhemoglobin. This finding was supported by increased erythropoietin and bilirubin values in cord blood and increased hematocrit values at day 3 among infants at 3100 m vs 1600 m. The sustained elevation in bilirubin for breast-fed vs formula-fed infants at 1600 m was observed for both feeding types at 3100 m. The findings suggested that there is a hematologic response to decreased oxygen availability at high altitude, resulting in increased bilirubin production accompanied by delayed bilirubin clearance.     

Malnutrition at age 3 years and lower cognitive ability at age 11 years: independence from psychosocial adversity

BACKGROUND: Early malnutrition is linked to poor cognition, but long-term effects have not been extensively examined and psychosocial confounds have not always been controlled. OBJECTIVE: To test the hypothesis that malnutrition at age 3 years will be associated with poorer cognitive ability at age 11 years independent of psychosocial confounds. DESIGN: A prospective, longitudinal study of a birth cohort of 1559 children originally assessed at age 3 years for malnutrition (low hemoglobin level, angular stomatitis, kwashiorkor, and sparse, thin hair) and followed up to age 11 years. SETTING AND PARTICIPANTS: A community sample of 1559 children (51.4% boys and 48.6% girls) born between September 1, 1969, and August 31, 1970, in 2 towns in the island of Mauritius, with 68.7% Indians and 25.7% Creoles (African origin). MAIN OUTCOME MEASURES: Verbal and spatial ability measured at ages 3 and 11 years and reading, scholastic ability, and neuropsychologic performance measured at age 11 years. RESULTS: Malnourished children had poorer cognition at both ages. Deficits were stable across time, applied to all sex and ethnic groups, and remained after controlling for multiple measures of psychosocial adversity. Children with 3 indicators of malnutrition had a 15.3-point deficit in IQ at age 11 years. CONCLUSIONS: Malnutrition at age 3 years is associated with poor cognition at age 11 years independent of psychosocial adversity. Promoting early childhood nutrition could enhance long-term cognitive development and school performance, especially in children with multiple nutritional deficits.     

Breast feeding and cognitive development at age 1 and 5 years

AIM—To examine whether duration of breast feeding has any effect on a child''s cognitive or motor development in a population with favourable environmental conditions and a high prevalence of breast feeding.METHODS—In 345 Scandinavian children, data on breast feeding were prospectively recorded during the first year of life, and neuromotor development was assessed at 1 and 5 years of age. Main outcome measures were Bayley''s Scales of Infant Development at age 13months (Mental Index, MDI; Psychomotor Index, PDI), Wechsler Preschool and Primary Scales of Intelligence (WPPSI-R), and Peabody Developmental Scales at age 5.RESULTS—Children breast fed for less than 3 months had an increased risk, compared to children breast fed for at least 6 months, of a test score below the median value of MDI at 13 months and of WPPSI-R at 5 years. Maternal age, maternal intelligence (Raven score), maternal education, and smoking in pregnancy were significant confounders, but the increased risk of lower MDI and total IQ scores persisted after adjustment for each of these factors. We found no clear association between duration of breast feeding and motor development at 13 months or 5 years of age.CONCLUSION—Our data suggest that a longer duration of breast feeding benefits cognitive development.     

Neonatal meningitis in England and Wales: sequelae at 5 years of age

This study determined the prevalence of serious sequelae among a national cohort of 5-year old children, born in England and Wales in 1996-7, who had had neonatal meningitis. The results were compared with those from two matched control groups. In addition the results from this study were compared with those from a previous 5-year follow-up of children who had had neonatal meningitis in 1985-7. Follow-up questionnaires requesting information about the children's health and development were sent to the general practitioners (GPs) and parents of the index children and controls. Information was collected on 166 of 232 (72%) children who had had meningitis as neonates, 109 general practice controls and 191 hospital controls. At 5 years, 39/166 (23%) index children had a serious disability compared to 2% of GP controls and 7% of hospital controls. There was a 16-fold increase in risk of serious disability compared to GP-matched controls and a 4-fold increase in risk compared to hospital controls. The isolation of bacteria from the CSF was the best single predictor of serious long-term disability. Although there was a 70% fall in acute phase mortality between 1985 (22%) and 1996 (6.6%), the overall incidence of serious disability remained alarmingly high, 25.5% in 1985 compared to 23.5% in 1996. In the present study, however, fewer children had cerebral palsy or seizure disorders. CONCLUSION: Despite the dramatic improvement in acute phase survival following neonatal meningitis, the prevalence of serious sequelae remains alarmingly high.     

Breast feeding and cognitive development at age 1 and 5 years.

AIM: To examine whether duration of breast feeding has any effect on a child's cognitive or motor development in a population with favourable environmental conditions and a high prevalence of breast feeding. METHODS: In 345 Scandinavian children, data on breast feeding were prospectively recorded during the first year of life, and neuromotor development was assessed at 1 and 5 years of age. Main outcome measures were Bayley's Scales of Infant Development at age 13 months (Mental Index, MDI; Psychomotor Index, PDI), Wechsler Preschool and Primary Scales of Intelligence (WPPSI-R), and Peabody Developmental Scales at age 5. RESULTS: Children breast fed for less than 3 months had an increased risk, compared to children breast fed for at least 6 months, of a test score below the median value of MDI at 13 months and of WPPSI-R at 5 years. Maternal age, maternal intelligence (Raven score), maternal education, and smoking in pregnancy were significant confounders, but the increased risk of lower MDI and total IQ scores persisted after adjustment for each of these factors. We found no clear association between duration of breast feeding and motor development at 13 months or 5 years of age. CONCLUSION: Our data suggest that a longer duration of breast feeding benefits cognitive development.     

Whole-body mineral measurements in Swedish adolescents at 17 years compared to 15 years of age

Aim: To provide reference data for bone mineral variables in 15- and 17-y-old adolescents and to analyse the relationships between these variables and measures of bone and body size, gender, puberty, growth, various lifestyle and environmental factors and socioeconomic background.

Methods: In the same 321 randomly selected adolescents (147 boys and 174 girls) living in two different regions of Sweden, the total bone mineral content (TBMC), bone area (BA) and total bone mineral density (TBMD) were assessed by dual-energy X-ray absorptiometry at ages 15 and 17 y. The effects of bone and body size, gender, growth, sexual maturity, physical activity, region of domicile, social conditions, food habits, smoking and alcohol intake on TBMC and TBMD were examined in multivariate analyses.

Results: In the 15-y-old adolescents, BA, height, gender, physical activity, maturity and weight explained 91% and 48%, of the variance in TBMC and TBMD, respectively. In similar analyses in the 17-y-olds, the corresponding figures were 92% and 62%, respectively, when BA, height, growth, physical activity, gender and region emerged as significant in the model. In all these analyses, BA explained most of the variance in TBMC and TBMD. No significant reduction of variance was found when different measures of social conditions, smoking, food habits, alcohol or dietary intakes of energy, calcium or vitamin D were included in the models. The reason why region of domicile had a significant impact on TBMC in the 17-y-olds is not known. The fact that the normal fluoride concentration in drinking water (1.1 mg/L) is 10 times higher in the region where TBMC was higher than in the other region is an interesting observation.

Conclusion: Almost 90% of the variance in TBMC and 50% of that in TBMD was explained by measures of bone and body size and only a few percent by gender, physical activity, Tanner stage, growth and region of domicile.     

Predicting curriculum and test performance at age 11 years from pupil background, baseline skills and phonological awareness at age 5 years

BACKGROUND: Phonological awareness tests are amongst the best predictors of literacy and predict outcomes of Key Stage 1 assessment of the National Curriculum in England at age 7. However, it is unknown whether their ability to predict National Curricular outcomes extends to Key Stage 2 assessments given at age 11, or also whether the predictive power of such tests is independent of letter-knowledge. We explored the unique predictive validity of phonological awareness and early literacy measures, and other pupil background measures taken at age 5 in the prediction of English, Maths, and Science performance at age 11. METHOD: Three hundred and eighty-two children from 21 primary schools in one Local Educational Authority were assessed at age 5 and followed to age 11 (Key Stage 2 assessment). Teaching assistants (TAs) administered phonological awareness tasks and early literacy measures. Baseline and Key Stage 2 performance measures were collected by teachers. RESULTS: Phonological awareness was a significant unique predictor of all nine outcome measures after baseline assessment and pupil background measures were first controlled in regression analyses, and continued to be a significant predictor of reading, maths, and science performance, and teacher assessments after early literacy skill and letter-knowledge was controlled. Gender predicted performance in writing, the English test, and English teacher assessment, with girls outperforming boys. CONCLUSIONS: Phonological awareness is a unique predictor of general curricular attainment independent of pupil background, early reading ability and letter-knowledge. Practically, screening of phonological awareness and basic reading skills by school staff in year 1 significantly enhances the capacity of schools to predict curricular outcomes in year 6.     

Growth and motor performance in preterm children at 8 years of age

At 8 years of age 41 preterm and 24 term children were followed up in a long-term prospective study of 46 unselected infants born before 35 completed weeks of gestation and of 26 term infants. The two groups were comparable in physical growth and there was no significant difference between them in motor performance, as evaluated with the Test of Motor Impairment. Only minor motor problems were found (in 22% of the preterm and 17% of the term group). In the preterm group, motor impairment was correlated to birthweight. The preterm children had less developed postural control and manifested more compensatory movements during the balance tasks than the term children.     

Prenatal drug exposure: effects on cognitive functioning at 5 years of age

The goal of this cross-sectional study was to compare cognitive functioning at age 5 years in prenatal drug-exposed children with nondrug-exposed children from a comparable inner-city environment. Children with prenatal drug exposure scored significantly lower on measures of language, school readiness skills, impulse control, and visual attention span/sequencing than controls matched for age and socioeconomic status. Intelligence, visual-motor, manual dexterity, and sustained attention scores were not significantly different between groups. The total sample scored significantly below the normative mean on standardized measures of intelligence, language, school readiness, visual-motor skills, impulse control, and sustained attention, with 40% scoring at least 1 standard deviation below the mean (IQ < 85) on a measure of intelligence. Findings suggest that children with prenatal drug exposure are at increased risk for learning and attention problems and are in need of close developmental surveillance and possible intervention to support school success and improve behavioral outcome.     

Neurodevelopmental outcome and school performance of very-low-birth-weight infants at 8 years of age

The neurodevelopmental outcome and school performance of 50 appropriate for gestational age (AGA) and 33 small for gestational age (SGA) very-low-birth-weight (VLBW) infants, compared to a control group (41 Term infants) were assessed at 8 years of age. The incidence of major handicaps among AGA and SGA/VLBW infants respectively, was 16% and 6%. No major handicap was found in the control group. The incidence of neurodevelopmental abnormalities (NDA) among AGA's (40%) and SGA's (57.6%) compared with the control group (31.7%) was found to be significantly higher. School failure occurred more frequently among VLBW infants (22.9%) and was related in children with NDA — and more particularly among AGA's — to the presence of language disorders of associated NDA. Evaluation of the consequences of NDA and school problems for later academic and professional achievement now requires further follow-up studies.     

Growth impairment in the very preterm and cognitive and motor performance at 7 years

Background: Infants born of low birth weight often have poor subsequent growth (especially if they were born very preterm), which has been shown to relate to later motor and cognitive development. Aims: To assess a cohort of preterm infants at the age of 7 years for growth, motor, and cognitive measures, and investigate the effects of growth impairment on school performance. Methods: A cohort of 280 children born before 32 completed weeks of gestation were tested, together with 210 term controls. Results: Pretem children were significantly lighter and shorter than term controls and had smaller heads and lower body mass index (BMI). Median centiles for weight, height, head circumference, and BMI were 25, 25, 9, and 50 for boys and 50, 25, 9, and 50 for girls compared with 50, 50, 50, and 75 for controls. They performed significantly less well on all tests with a mean score of 91 (9.2) on the Developmental Test of Visual-Motor Integration, 89 (14.5) on the Wechsler-III IQ test, and 30.7% scoring at or below the 5th centile on the Movement Assessment Battery for Children. In boys, short stature and small heads were the best predictors of poor performance; in girls, a small head alone was a predictor for poor motor and cognitive performance. Conclusion: Poor postnatal growth in preterm infants, especially of the head, is associated with increased levels of motor and cognitive impairment at 7 years of age. This growth restriction appears to occur largely in the postnatal rather than antenatal period and may be amenable to intervention and subsequent improvement in outcome.     

Association of growth in utero with cognitive function at age 6-8 years

BACKGROUND: Size at birth is associated with later cognitive development. The timing of growth faltering in utero may affect developmental consequences. AIM: To determine whether growth in utero is related to cognitive outcomes in childhood. A secondary aim was to determine any associations between maternal nutritional status and cognition. STUDY DESIGN AND SUBJECTS: Subjects were participants in a prospective cohort study of developmental origins of adult disease. Eligible subjects were aged 6-8 years at their next scheduled visit to the study clinic and their mothers had abdominal ultrasound measurements at 14, 25 and 35 weeks gestation. 186 of 264 eligible children attended the clinic and were tested. OUTCOME MEASURES: Raven's Progressive Matrices (reasoning ability), Peabody Picture Vocabulary Test (receptive vocabulary) and Digit Span Forwards (auditory working memory). RESULTS: In multiple regression analyses controlling for children's age and socioeconomic status, head circumference at 14 weeks gestation was significantly associated with reasoning ability. The difference between the lowest and highest quartiles was equivalent to 0.4 S.D. No other significant associations with fetal growth were found. Maternal weight gain was not associated with cognitive scores; however, change in triceps skinfold between 25 and 35 weeks gestation was positively associated with reasoning ability and remained a significant predictor when included in the regression model. CONCLUSIONS: There were few associations between growth in utero and cognition. Growth in head circumference in early gestation and maternal nutrition in late gestation may affect later cognitive ability. Further research in this area is needed to confirm these results.     

Neonatal hyperbilirubinemia: myths and realities]

This paper reproduces the introducing talk of the round table conference on current management of neonatal hyperbilirubinemia held during the Journée d'Actualité Lorraine en Néonatologie (JALON 2002, Nancy, october 5th 2002).