Sex differences in weight in infancy. Published centile charts for weights have been updated

The influence of birth weight amongst 33-35 weeks gestational age (wGA) infants on the risk of respiratory syncytial virus (RSV) hospitalisation: a pooled analysis

OBJECTIVE

To investigate the association between birth weight and respiratory syncytial virus (RSV) hospitalisation during the first year of life in 33°-35⁶ weeks' gestational age (wGA) infants.

STUDY DESIGN

Pooled analysis of data (n = 1218) from Spain, Germany, France and Italy.

RESULT

RSV hospitalised infants overall had a significantly higher birth weight than non-hospitalised infants (2.24 versus 2.14 kg; p < 0.001) for both males (2.25 versus 2.18 kg; p = 0.049) and females (2.22 versus 2.11 kg, p = 0.007). The effect was significant only in 34 wGA infants (33 wGA: hospitalised 1.95 kg versus non-hospitalised 1.95 kg, p = 0.976; 34 wGA: 2.26 versus 2.14 kg, p = 0.007; 35 wGA: 2.37 versus 2.29 kg, p = 0.070), particularly female 34 wGA infants (female: 2.24 versus 2.08 kg, p = 0.019; male: 2.27 versus 2.20, p = 0.191). Birth weight was shown to be an independent risk factor for RSV hospitalisation.

CONCLUSIONS

In 33-35 wGA infants, a higher birth weight appeared independently associated with an increased risk of RSV hospitalisation.

Troponin T and pro-B-type natriuretic Peptide in fetuses of type 1 diabetic mothers

OBJECTIVE

Cardiomyopathy is noted in up to 40% of infants of diabetic mothers, and the exact mechanisms are unknown. The aim of this study was to determine whether fetal serum markers of cardiac function differ between normal and type 1 diabetic pregnancies and to examine the relationship between these markers and fetal cardiac structure and function.

RESEARCH DESIGN AND METHODS

This was a prospective observational study of 45 type 1 diabetic pregnancies and 39 normal pregnancies. All participants had concentrations of fetal pro-B-type natriuretic peptide (proBNP) and troponin-T (TnT) measured at the time of delivery. All patients with type 1 diabetes had Doppler evaluation of the umbilical artery, middle cerebral artery, and ductus venosus in the third trimester, and a subset (n = 21) had detailed fetal echocardiograms performed in each trimester.

RESULTS

Fetal proBNP and TnT concentrations were higher in the diabetic cohort than in the normal cohort (P < 0.05). ProBNP correlated positively with interventricular septum thickness (P < 0.05) but not with cardiac function indexes in the third trimester. In patients with poor glycemic control, there was a significant positive correlation (P < 0.05) between fetal TnT and the third trimester umbilical artery pulsatility index. There were also increased levels of fetal TnT in infants with poor perinatal outcome (P < 0.05).

CONCLUSIONS

Biochemical markers of cardiac dysfunction are elevated in infants of diabetic mothers, especially those with cardiomyopathy or poor perinatal outcome. Hyperglycemia in early pregnancy may affect myocardial and placental development, thus contributing to the susceptibility to hypoxia seen in these infants.

Food and nutrient intakes of 9-month-old infants in Adelaide, Australia

OBJECTIVE

To describe the food and nutrient intakes of 9-month-old infants.

DESIGN

A survey undertaken as part of a longitudinal study of child growth and development. Infant diet was characterised through a structured interview in which consumption frequency and portion size of foods were obtained. This method was compared with a 4 d diary and had adequate relative validity.

SETTING

Adelaide, Australia.

SUBJECTS

Three hundred and forty-one infants for whom dietary data were plausible according to pre-specified criteria.

RESULTS

At 9 months of age, the median body weights for 161 girls and 180 boys were 8.8 and 9.6 kg, respectively. Differences in intakes between boys and girls largely reflected differences in size. Median daily energy intake was 3541 kJ and median contributions of protein, fat and carbohydrate to total energy were 13 %, 36 % and 50 %. Using published Estimated Average Requirements, Zn intake was inadequate for <1 % of children not breast-fed at this age while Fe intake was inadequate for 9 %. Infants who were still breast-fed (35 %) had more diversity in the foods that provided additional energy, compared with those not receiving breast milk, and were less likely to consume nutrient-displacing drinks such as juice or cordial. Cow's milk was the main drink for 5 % of infants.

CONCLUSIONS

In a group of Australian-born children, an important proportion had weaning diets that were low in Fe. Fat intake of many children was below current recommendations and cow's milk was the main milk source for a small minority.

Correlation models for monitoring child growth

Growth measurements of children, such as weight and height, are monitored regularly, particularly in infancy, to assess whether or not a child's growth is normal when compared with a reference population of the same age and sex. Here, after a suitable power transformation to normality of the reference population, we model temporal evolution of the standardized deviation (Z-score) of the transformed measurement of a normal child from the reference population as a Gaussian process with zero mean and unit variance. This paper concentrates on modelling and fitting the serial correlation structure of the process, with the benefit that monitoring growth at specific ages is not crucial, statistically. Exploratory analysis of various observed correlation matrices has suggested that a particular two-parameter Markovian form is a good representation of the correlation function in infancy. The main implication for growth monitoring is that we only need to condition on the most recent Z-score to inform a clinician's judgement about a child's growth based on its current Z-score. Inferences about the correlation parameters derive from likelihood methods based either on observed Z-scores or, if raw data are unavailable, on an observed correlation matrix. The Markov model is compared with a previously studied six-parameter correlation model. Data from major child growth studies in Newcastle and Cambridge are used to illustrate the methods and compare predictions from the two models. We argue that the Markov model serves as a pragmatic choice for growth monitoring in infancy.

High-energy and -protein diet increases brain and corticospinal tract growth in term and preterm infants after perinatal brain injury

OBJECTIVE

Our hypothesis was that infants with perinatal brain injury fail to thrive in the first postnatal year because of increased energy and protein requirements from deficits that accumulated during neonatal intensive care. Our aim was to assess whether dietary energy and protein input was a rate-limiting factor in brain and body growth in the first year after birth.

METHODS

We conducted a prospective, double-blind and randomized, 2-stage group sequential study and controlled for gestation, gender, and brain lesion. Neonates with perinatal brain damage were randomly allocated to receive either a high- (120% recommended average intake) or average (100% recommended average intake) energy and protein diet. The study began at term and continued for 12 months. Three-day dietary diaries estimated energy and protein intake. The primary outcome measure was growth of occipitofrontal circumference. Other measures were growth of axonal diameters in the corticospinal tract, which were estimated by using transcranial magnetic stimulation, weight gain, and length.

RESULTS

The study was terminated at the first analysis when the 16 subjects had completed the protocol, because the predetermined stopping criterion of >1 SD difference in occipitofrontal circumference at 12 months' corrected age in those receiving the higher-energy and -protein diet had been demonstrated. Axonal diameters in the corticospinal tract, length, and weight were also significantly increased.

CONCLUSIONS

These data support our hypothesis that infants with significant perinatal brain damage have increased nutritional requirements in the first postnatal year and suggest that decreased postnatal brain growth may exacerbate their impairment. There are no measures of cognitive ability at 12 months of age, and whether there will be any improvement in the status of these children, therefore, remains to be shown.

Milk intake and feeding behavior in the first week of life and its relationship to cord blood ghrelin, leptin, and insulin concentrations

Our aim was to study the feeding behavior of healthy term infants in the first week of life and determine whether this was related to cord blood leptin, ghrelin, and insulin. A total of 100 healthy bottle-fed infants were studied by weighing bottles of milk before and after feeds. Leptin, total ghrelin, and insulin concentrations were measured in cord blood. Mean (SD) birth weight was 3.46 (0.43) kg. Mean milk intake increased from 196.7 (83.0) g on d 1 to 585.0 (128.4) g on d 7. Milk intake over the first 6 d was significantly associated with weight gain to d 7. There was no relationship between cord ghrelin or leptin and milk intake or feed frequency. Cord blood insulin was inversely related to the mean daily number of feeds over the first 6 d (r = -0.21, p < 0.05). Birth weight and milk intake are the major determinants of weight gain in the first week of life in healthy bottle-fed infants. Total cord ghrelin and leptin are not directly related to milk intake or feed frequency in the first week of life. Circulating insulin concentrations may have a role in the initiation of feeding behavior.

Breast-feeding in a UK urban context: who breast-feeds, for how long and does it matter?

Objective

To investigate what factors relate most strongly to breast-feeding duration in order to successfully support breast-feeding mothers.

Design

Prospective birth cohort study using questionnaires, routinely collected weights and health check at age 13 months.

Setting

Gateshead, UK.

Subjects

Parents of 923 term infants born in a defined geographical area and recruited shortly after birth, 50% of whom were breast-feeding initially.

Results

Only 225 (24%) infants were still breast-fed at 6 weeks, although 136 (15%) continued beyond 4 months. Infants in the most affluent quintile were three times more likely to be initially breast-fed (P < 0.001) and five times more likely to still be feeding at 4 months (P = 0.001) compared with infants in the most deprived quintile. A third of breast-fed infants were given supplementary feeds in the maternity unit and this was associated with a 10-fold increase in odds of giving up breast-feeding by discharge (P = 0.001). Frequent feeding was reported as a reason for giving up in 70% of mothers at 6 weeks and 55% at 4 months. Those infants who stopped breast-feeding earliest showed the most rapid weight gain and were tallest at age 13 months. Non-breast-fed infants had 50% more family doctor contacts up to age 4 months (P = 0.005).

Conclusions

Initiation of breast-feeding in urban Britain remains strongly determined by socio-economic background and early cessation seems to be related to frequent feeding and rapid growth as well as a continuing failure to eradicate health practices that undermine breast-feeding. Those infants not receiving breast milk suffered increased morbidity, but the apparent association between breast-feeding duration and growth probably reflects reverse causation.

Altered gene expression patterns in intrauterine growth restriction: potential role of hypoxia

OBJECTIVE

Placental insufficiency is a primary cause of intrauterine growth restriction (IUGR). In our study, microarray technology was used to identify genes, which may impair placentation resulting in IUGR.

STUDY DESIGN

The RNA was isolated from both IUGR term placentas and normal term placentas. Microarray experiments were used to identify differentially expressed genes between the 2 cohorts. Real-time quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry were used in follow-up experiments.

RESULTS

Microarray experiments identified increased expression of certain genes including leptin, soluble vascular endothelial growth factor receptor, human chorionic gonadotropin, follistatin-like 3, and hypoxia-inducible factor 2alpha in the IUGR. Real-time quantitative polymerase chain reaction confirmed these results.

CONCLUSION

The upregulation of soluble vascular endothelial growth factor receptor and hypoxia-inducible factor 2alpha at this period in pregnancy indicate that placental angiogenesis is altered in IUGR and that hypoxia is a major contributor to maldevelopment of the placental vasculature.

The relationship between birthweight, weight gain in infancy, and educational attainment in childhood

Previous studies have examined the relationship between low weight gain (failure to thrive) in infancy and later cognitive ability, but no study to date appears to have examined the relationship between weight gain in infancy across the 'normal' range and later cognitive ability. We report results for a large prospective birth cohort of the relationship between weight gain in infancy and educational attainment at age 10. Routinely recorded weights from child health clinic records for an annual birth cohort of 3418 children born with gestation >36 weeks were collected, as well as gestation in weeks, birthweight and the postcode, for which the Townsend Deprivation Score was identified. At 10 years of age, those attending schools within the Newcastle Education Authority were given a picture vocabulary and a non-verbal ability test, and tests of educational attainment in maths and reading. These were successfully linked to the infant weight data for 2294 (63%) of the children, and complete growth data were available for 1724 (47%) of the children who had completed at least one educational test. There was a significant positive relationship between weight gain in infancy and picture vocabulary, adjusted for economic deprivation, gestational age and birthweight, but not with any of the other outcomes. There was a statistically significant association between birthweight and all four outcomes, which was positive up to about one SD above average birthweight, and negative above. In this population, the association between early growth and cognitive outcomes is stronger for growth before birth, postnatal weight gain having a relatively minor impact.

Body mass index has risen more steeply in tall than in short 3-year olds: serial cross-sectional surveys 1988–2003

OBJECTIVE

To monitor the changing relationship between body mass index (BMI) and height in young children.

DESIGN

Annual cross-sectional surveys using health-visitor-collected routine data 1988-2003.

SETTING

Wirral, England.

PARTICIPANTS

Fifty thousand four hundred and fifty-five children (49% female) each measured once at the age of 3 years.

MAIN OUTCOME MEASURES

Weight, height and derived BMI (weight/height(2)) adjusted for age and sex (British 1990 revised reference) using standard deviation scores.

RESULTS

From 1988 to 2003, mean BMI increased by 0.7 kg/m(2), whereas mean height fell by 0.5 cm. Over the same period, the weight-height correlation rose from 0.59 to 0.71 (P<0.0001) owing to BMI increasing faster in the taller than the shorter children. Among the shortest 10% of children, mean BMI rose by 0.12 (95% confidence interval: -0.05-0.28) kg/m(2) as against 1.38 (1.19-1.56) kg/m(2) among the tallest 10%, a 12-fold difference. Adjustment for age, sex, seasonality, birth-weight and deprivation did not alter the findings.

CONCLUSIONS

Among 3-year-old children in Wirral, where BMI has been rising for 16 years, the largest increase in BMI has occurred in the tallest children, whereas in the shortest BMI has hardly changed. Tall stature has, therefore, become important for child obesity. It suggests a drive to increasing adiposity in young children that involves both growth and appetite, with fast growing and hungrier children now more exposed to the 'obesogenic' environment.

Physical and emotional development, appetite and body image in adolescents who failed to thrive as infants

BACKGROUND

Previous studies suggest that failure to thrive in infancy may be associated with adverse sequelae in childhood. Although cognitive abilities have been extensively investigated, little systematic research is available on other aspects of development.

METHODS

Eighty-nine children who failed to thrive as infants and 91 controls were followed up when twelve years old and examined using anthropometric measurement, self-ratings of appetite and body image, the Dutch Eating Behaviour Questionnaire, the Self-perception Profile for Children, The Revised Children's Manifest Anxiety Scale, the parent and child form of the Mood and Feelings Questionnaire and the parent and teacher's form of the Child Behavior Checklist.

RESULTS

The children who failed to thrive were significantly shorter and lighter at twelve and had significantly lower BMIs, but they did not go into puberty any later. They were more likely to rate their appetite as lower than their best friend's, were generally more satisfied with their body shape, and had significantly lower restraint score on the Dutch Eating Behaviour Questionnaire. They were not significantly different from controls on any of the measures reflecting anxiety, depression or low self-esteem.

CONCLUSIONS

Failure to thrive in infancy is not associated with adverse emotional development in childhood.

The influence of maternal socioeconomic and emotional factors on infant weight gain and weight faltering (failure to thrive): data from a prospective birth cohort

AIMS

To study the influence of maternal socioeconomic and emotional factors on infant weight gain and weight faltering (failure to thrive) in the first year of life.

METHODS

The Gateshead Millennium Baby Study is a population birth cohort in northeast England studied prospectively from birth, via parental questionnaires and a health check aged 13 months. Data were collected on maternal education, deprivation, eating attitudes, and depression, using the Edinburgh Post Natal Depression Scale (EPDS) at 3 months. Weight gain was assessed using change in weight SD score, conditional on birth weight (Thrive Index); weight faltering was defined as conditional weight gain below the 5th centile.

RESULTS

Of 923 eligible infants born at term, 774 (84%) had both weight and questionnaire data. Replicating a previous finding, both the highest and the lowest levels of deprivation were associated with weight faltering; this was independent of the type of milk feeding. No relation was found with maternal educational status. Maternal eating restraint was unrelated to weight gain. Infants of mothers with high depression symptom scores (EPDS >12) had significantly slower weight gain and increased rates of weight faltering up to 4 months (relative risk 2.5), especially if they came from deprived families, but by 12 months they were no different from the remainder of the cohort.

CONCLUSIONS

In this setting, social and maternal characteristics had little influence on infants' weight gain, apart from a strong, but transient effect of postnatal depression.

Sex differences in the relationships among weight gain, subcutaneous skinfold tissue and saltatory length growth spurts in infancy

As the mechanisms controlling the amount and timing of growth saltations are not well understood, the identification of physiologic coupling in weight and length growth are important for further understanding normal growth biology. Thirty-four healthy infants (13 males, 21 females) participated in a longitudinal growth study during the first year. Weekly weights and s.c. skinfolds (limb and trunk) were analyzed in a growth event-focused study. Coincident analysis tested the null hypothesis of chance concurrence between significant weight gain and saltatory length growth spurts. Logistic regression quantified this relationship and investigated the interaction between incremental weight gain and s.c. skinfolds on length growth spurts. The null hypothesis of random coincidence between weight gain and saltatory length growth was not supported. For girls, significant weight gain and length growth were coupled during the same week and length saltations were 42% more likely during the weeks of significant weight gain, with no interaction from s.c. skinfolds. For boys, length growth saltations were coupled to both previous and concomitant weight gain but were predicted only by previous weight gain, controlling for confounders. Boys were 68% more likely to grow in length the week following significant weight gain, and initial abdominal to suprailiac skinfold ratios conferred a 4-fold increased likelihood of length growth within the week, controlling for confounders. These data generate the hypothesis that a common growth signal cascade couples growth in weight and length/height with a time delay due to sex-specific biology, reflected in a s.c. fat fold interface.

Growth hormone (GH) provocation tests and the response to GH treatment in GH deficiency

OBJECTIVE

To identify factors, particularly the growth hormone (GH) provocation test result, affecting growth response to GH treatment in children with GH deficiency (GHD).

SUBJECTS

A total of 337 prepubertal GHD patients aged <10 years from the UK Pharmacia KIGS database (GH response to provocation test <20 mU/l).

OUTCOME MEASURE

Annual change in height standard deviation score (SDS) (revised UK reference) in the first and second years of treatment.

RESULTS

Height increased by 0.74 SDS units (SD 0.39) in the first year of treatment and 0.37 units (SD 0.27) in the second. Adjusting for age, height, weight, midparent height, and injection frequency, the strongest predictor of first year growth response was the GH provocation test result; halving the result predicted an extra height increment of 0.09 units (p<0.0001). It predicted the second year response less well (p<0.0002) and after adjusting for the first year response was not predictive at all.

CONCLUSIONS

Among patients referred for possible GHD, the GH provocation test, though not a gold standard for diagnosis, is a valuable predictor of growth response in the first year of treatment. A year's treatment is recommended for cases with a marginal provocation test result, with the option to continue treatment if the response is adequate. The value of unified protocols for single or repeated provocation tests needs to be assessed.

The diagnosis of borderline iron deficiency: results of a therapeutic trial

BACKGROUND

Iron deficiency is common in early childhood and has been associated with developmental delay. It is not known how reliably markers of iron deficiency identify true iron deficiency, defined as a therapeutic response to oral iron.

METHODS

The subjects were members of the Millennium Baby Study cohort. At age 13 months a venous blood sample was taken for mean cell volume (MCV), haemoglobin, mean cell haemoglobin (MCH), ferritin, and zinc protoporphyrin (ZPP). Children with abnormal values were offered treatment with oral iron and dietary modification, and re-sampled after 3 months.

RESULTS

Samples were obtained for 462 children. All markers were moderately correlated with each other except ferritin. Treatment was offered to 147 (32%) children with at least one abnormal value, of whom 126 (86%) were re-sampled. Children with a haemoglobin or an MCH below the screening cut off, or with abnormal values for two or more of the remaining three measures, showed a large therapeutic response to iron, but isolated abnormalities of MCV, ZPP, or ferritin were not consistently associated with a response. Of the screened population 13% could be defined as iron deficient (abnormal haemoglobin or MCH, or abnormal levels of two or more of the remaining three markers), but this was not strongly associated with any dietary, demographic, or anthropometric characteristic.

CONCLUSIONS

Low total or mean cell haemoglobin in isolation is a specific marker of iron deficiency, but other markers are only predictive when found in combination with other abnormal values.

Why are babies weaned early? Data from a prospective population based cohort study

BACKGROUND

The recommended age of introduction of solids food to the diet of infants (weaning) has recently been increased in the UK to 6 months, but most babies are still weaned before the age of 4 months.

AIMS

To examine what predicts the age of weaning and how this relates to weight gain and morbidity using data from a population based cohort.

METHODS

Parents of 923 term infants born in a defined geographical area and recruited shortly after birth were studied prospectively using postal questionnaires, weaning diaries, and routinely collected weights, of whom 707 (77%) returned data on weaning.

RESULTS

The median age of first weaning solids was 3.5 months, with 21% commencing before 3 months and only 6% after 4 months of age. Infants progressed quickly to regular solids with few reported difficulties, even when weaned early. Most parents did not perceive professional advice or written materials to be a major influence. The strongest independent predictors of earlier age at weaning were rapid weight gain to age 6 weeks, lower socioeconomic status, the parents' perception that their baby was hungry, and feeding mode. Weight gain after 6 weeks was unrelated to age of weaning. Babies weaned before 3 months, compared to after 4 months, had an increased risk of diarrhoea.

CONCLUSIONS

Social factors had some influence on when weaning solids were introduced, but the great majority of all infants were established on solids before the previously recommended age of 4 months, without difficulty. Earlier weaning was associated with an increased rate of minor morbidity.

Mealtime energy intake and feeding behaviour in children who fail to thrive: a population-based case-control study

BACKGROUND

The essential link between energy needs and energy intake is feeding behaviour, yet few studies have directly observed feeding behaviour in children who have failed to thrive. A cohort of 961 term infants was screened to identify children with first year weight gain below the 5th centile in order to examine their feeding behaviour and food intake.

METHODS

A nested case-control study was used with direct observation at 13-21 months over two lunchtime meals, one consisting of finger foods and the other of 'spoon foods'. Thirty children who failed to thrive and 57 controls were studied. The video-tapes were coded for feeding behaviour using a behavioural coding inventory which distinguishes between children feeding themselves and responding to being fed by their mother. The main outcome measures were counts of five feeding actions (give, accept, feedself, refuse, reject) and measures of energy intake, the weight of food eaten and meal duration.

RESULTS

There were systematic differences in feeding behaviour between meal types, with mothers feeding their child more often at meals comprising spoon foods and children feeding themselves more often at meals comprising finger foods. By weight, more food was consumed at the spoon food meals, but energy intake was no higher, showing that the children compensated for the differing energy yields of the foods. Children who failed to thrive took in less energy than controls, and were less likely to sit in a highchair throughout the meal, but there were no clear differences in other aspects of feeding behaviour.

CONCLUSIONS

Food type is an important variable when studying childhood feeding behaviour. Children who fail to thrive take in less energy than controls of the same age, despite there being no major differences in mealtime feeding behaviour.

To what extent is failure to thrive in infancy associated with poorer cognitive development? A review and meta-analysis

BACKGROUND

Previous empirical studies of the cognitive sequelae of failure to thrive in infancy have led to apparently inconsistent conclusions.

METHODS

Studies of cognitive abilities in failure to thrive were located through published bibliographies, supplemented by a search through MEDLINE. They were classified (a) into those in which the cases were identified in hospital or other specialist clinics, and those in which they were identified in primary care or by whole population screening; (b) into those that were controlled and those that were not controlled; and (c) into those with a cross-sectional and those with a longitudinal design. Effect sizes in controlled studies were summarised using D statistics for the principal cognitive outcome measure, from the last occasion on which the child was tested if the study was longitudinal.

RESULTS

In studies with cases identified in hospital or other specialist clinics (52 cases, 36 controls), the pooled effect size (weighted standardised mean difference) for cognitive outcomes was -.85 (95% CI -.41 to -1.30). In studies with cases identified in primary care (552 cases, 573 controls), it was -.30 (95% CI -.18 to -.42). In each longitudinal study testing the same children at different ages, the effect size was smaller when the children were older. To obtain an overall estimate of the long-term cognitive outcome of failure to thrive in infancy, data from controlled studies in which cases were identified in primary care, and restricted to IQ or McCarthy scale scores in older children (502 cases, 523 controls), were used. The weighted mean difference was -.28 (95% CI -.16 to -.41), equivalent to 4.2 IQ points (95% CI 2 to 6).

CONCLUSIONS

Evidence from reasonably well-controlled studies indicates that failure to thrive in infancy is associated with adverse intellectual outcomes sufficiently large to be of importance at a population level.

Failure to thrive in the term and preterm infants of mothers depressed in the postnatal period: a population-based birth cohort study

AIMS

To examine the relationship between failure to thrive in preterm and term infants and postnatal depression in their mothers.

METHOD

In a whole population birth cohort of 12,391 infants (excluding those born after term or with major congenital abnormalities) failure to thrive over the first nine months was identified using a conditional weight gain criterion which identified the slowest-gaining 5%. Depression symptoms were recorded using the Edinburgh Postnatal Depression Scale (EPDS) at 18 and 32 weeks of pregnancy and at 8 weeks and 8 months after delivery.

RESULTS

After the birth, high depression scores were significantly more common in the mothers of infants born preterm, and controlling for depression scores in pregnancy did not eliminate this association after the birth. Failure to thrive was identified in 4.5% of the children born at term (531/11718) and in 8.3% of those born preterm (56/673). The difference was highly significant (chi2 = 20.25 with 1 df, p < .0001). Using a conventional cut-off on the EPDS (score > 12) to identify mothers as 'depressed', the prevalence of failure to thrive in the term infants of mothers depressed at 8 weeks postpartum was 5.0%; in the remainder of the population (controls) it was 4.3%. In mothers depressed at 8 months the prevalence was 4.3% in both groups. The prevalence of failure to thrive in the preterm infants of mothers depressed at 8 weeks was 8.8% (7.0% in controls) and in those depressed at 8 months it was 12.3% (6.7% in controls). None of these differences in prevalence was statistically significant, and significant differences did not emerge from further analyses using more stringent criteria for depression.

CONCLUSIONS

Preterm births are specifically associated with high maternal depression scores in the postpartum period, and with a higher prevalence of failure to thrive. High depression scores in the postpartum period are not themselves associated with a higher prevalence of failure to thrive, however, either in infants born at term or in those born preterm.

Feeding behaviour in young children who fail to thrive

One-year-old children who failed to thrive in infancy were identified through a specialist clinical service using a conditional weight gain criterion which identified the slowest gaining 5%. Control children of the same age and sex were recruited from the same local geographical area and had the same primary care physician. The food intake and feeding behaviour of the groups was compared using a detailed observational micro-analysis of a lunchtime meal, using a behavioural coding scheme developed for use over the weaning period. Both food and fluid intake at the test meal were significantly lower in the children who failed to thrive than the controls. There was no significant difference in the energy density of the foods they consumed. As recorded in the behaviour counts at the meal, the mothers of the children who failed to thrive fed them as much as or more than the control mothers fed their children. The children who failed to thrive tended to refuse or reject the offered food more, and also fed themselves significantly less often than the controls. These behavioural differences during the meal accounted for about one third of the difference in energy intake between the groups.

Energy compensation in young children who fail to thrive

BACKGROUND

Failure to thrive is generally attributed to undernutrition, but little is known about the appetite or eating behaviour of children with the condition. The hypothesis that young children who fail to thrive lack a normal sensitivity to internal hunger or satiation cues was tested in this study using an energy compensation procedure.

METHOD

Twenty-seven children under assessment by a community-based service for failure to thrive, with weight gain in the lowest 5% for their age, were studied at one year of age with 26 controls of the same age and sex with normal weight gain, resident in the same local geographical area. Test meals were given in the child's own home on two separate days. The test meals were preceded by either a high energy (402 kJ) drink, or by a low energy (1 kJ) drink on a control day. The order was randomised, and the study conducted double blind, without the experimenter or the mother knowing which drink was which. Energy intake at the test meal was measured.

RESULTS

There was no significant difference in the birth weight of the children in the two groups but by the time of the test the cases weighed significantly less than controls, with mean (SD) weight 9.06 (1.05) kg and 11.59 (1.59) kg respectively. In relation to the British Growth Reference for weight this is a difference of 2.2 SD. Mean (SD) energy intake at the meal on the control day was significantly lower in the case children than the controls (FTT 687.5 (334.3) kJ; controls 1065.9 (431.8) kJ; p < .001). After the high energy drink, controls reduced their energy intake at the meal by a mean (SD) -257.3 (383.3) kJ while the cases showed a slight average increase of +78.1 (365.9) kJ; t = 3.26, df 51, p < .001. Per kJ of the pre-load, the average change was -1.18 kJ in controls and +0.80 kJ in cases.

CONCLUSIONS

The controls compensated as expected for their high energy load at the subsequent meal, but the case children did not, showing that they lack the normal responses to internal hunger/satiation cues. High energy snacks may improve the nutritional status of children who fail to thrive.

Growth reference charts for use in the United Kingdom

Since the introduction of new growth charts in the mid 1990s, there has been confusion about which charts should be used, with many districts using more than one version. Because of this uncertainty, an expert working party, the Growth Reference Review Group, was convened by the Royal College of Paediatrics and Child Health to provide guidance on the validity and comparability of the different charts currently in use. This paper describes the technical background to the construction and evaluation of growth charts and outlines the group's findings on the validity of each growth reference in relation to contemporary British children. The group concluded that for most clinical purposes the UK90 reference is superior and for many measures is the only usable reference that can be recommended, while the original Tanner-Whitehouse and the Gairdner-Pearson charts are no longer reliable for use at any age. After the age of 2 the revised Buckler-Tanner references are still suitable for assessing height. There are presently no reliable head circumference reference charts for use beyond infancy. The group propose that apart from refinements of chart design and layout, the new UK90 reference should now be "frozen", with any future revisions only undertaken after careful planning and widespread consultation.

Sex hormone binding globulin concentration as a prepubertal marker for hyperinsulinaemia in obesity

BACKGROUND

Overweight children become obese adults who are prone to develop the "metabolic syndrome" and premature coronary arterial disease (CAD).

AIMS

To assess whether sex hormone binding globulin (SHBG) is a potential marker for hyperinsulinaemia/insulin resistance in prepubertal obese children.

METHODS

Twenty five obese children (body mass index (BMI) >2SD) who warranted investigation on clinical grounds were enrolled. Their insulin response to an oral glucose tolerance test was assessed.

RESULTS

Fourteen children were hyperinsulinaemic. Despite being matched for age and BMI, SHBG concentrations were below the sex related reference range in the hyperinsulinaemic group.

CONCLUSION

Our results indicate that a subnormal SHBG concentration in a prepubertal child is strongly predictive of hyperinsulinaemia. By measuring the circulating SHBG concentration, it might be possible to identify those at most risk of premature CAD, targeting them for lifestyle changes.

The strengths and limitations of parental heights as a predictor of attained height

Mid-parental heights are widely used to help assess an individual child's growth. However, the methods in use vary, and most make no allowance for extremes of parental height. This study aimed to examine the actual distribution of parental heights in a survey population and the relation with their children's heights. The heights of 419 representatively sampled children aged 8-9 years were compared with their reported mid-parental heights, all expressed as standard deviation scores (SDS). These confirmed previous predictions that 90% of the children's heights would fall within 1.5 SDS (approximately two centile spaces) of their mid-parental heights. However, where parents were unusually tall or short, their children were relatively less tall or short, respectively, and the mid-parental height was a poor predictor of attained height. A simple calculator for expected height centile is described that automatically adjusts for this regression to the mean. Of 13 children below the second centile for height, eight were within two centile spaces (90% range) of their mid-parental height SDS. However, when allowance was made for regression to the mean, only three of 13 were within the 90% range. Although mid-parental height provides a useful guide to expected height centile for children and parents of average stature, it can be misleading when used to assess short children.

Prevalence of protein-energy malnutrition at diagnosis in children with acute lymphoblastic leukemia

BACKGROUND

The purpose of the present study was to test the hypothesis that protein-energy undernutrition is common in patients with acute lymphoblastic leukemia at diagnosis. Previous studies have failed to establish whether undernutrition is a common feature at diagnosis.

METHODS

Body mass index (BMI, weight/height2), expressed as a standard deviation score (SDS) relative to contemporary United Kingdom reference data, was used as the index of nutritional status. The index was calculated in a national cohort of standard-risk patients (n = 1019) treated in the same protocol in the United Kingdom.

RESULTS

Prevalence of undernutrition (defined as BMI SDS <-2.0) exceeded expected frequencies in boys (7.6%) and girls (6.7%). These differences were statistically significant (p < 0.001), with a 95% confidence interval for the prevalence of undernutrition of 5.8% to 9.0%.

CONCLUSIONS

Undernutrition is relatively common in patients with newly diagnosed acute lymphoblastic leukemia, with a threefold excess of patients below the cutoff used to define undernutrition. Screening for undernutrition at diagnosis of acute lymphoblastic leukemia is indicated, and the BMI SDS is a simple index of nutritional status that could be readily calculated using measurements routinely made at diagnosis. The same simple screening technique could also be used clinically to detect and manage or prevent overnutrition (obesity), which is common in these patients after diagnosis.

Adequacy of standards for assessment of growth and nutritional status in infancy and early childhood

BACKGROUND

New "UK 1990" data have been proposed for assessing growth and nutritional status in infancy and childhood. These are still largely untried in clinical practice. There is also doubt about the applicability of more traditional reference data, which are still widely used, in assessing length, weight, skinfold thicknesses, and head circumference.

AIMS

To determine the suitability of new and traditional reference data for the assessment of growth and nutritional status in infancy and early childhood.

METHODS

127 infants were recruited at birth and assessed monthly to 6 months of age then at 9, 12, 18, and 24 months. Length, weight, head circumference, and triceps and subscapular skinfold thicknesses were measured. Body mass index (BMI) was calculated. Measurements were expressed as standard deviation scores relative to "revised UK 1990" data for weight, length, head circumference and BMI; relative to Tanner-Whitehouse data for skinfold thicknesses; and relative to Gairdner-Pearson standards for head circumference. Agreement at the extremes of the distribution was assessed by comparison of observed and expected frequencies above the 90th and below the 10th centile.

RESULTS

Compared with the revised UK 1990 references small differences were found for weight, length, head circumference, and BMI. Mean head circumference exceeded Gairdner-Pearson standards at all ages. Triceps and subscapular skinfold thicknesses were substantially below Tanner-Whitehouse reference data at all ages and in both sexes.

CONCLUSION

Biases in revised UK 1990 reference data are small and not clinically important. The new standards are considerably more appropriate than older reference data. Use of older reference data for head circumference and skinfold thicknesses is inappropriate.

New chart to evaluate weight faltering

A new chart was designed to aid accurate identification of weight faltering and failure to thrive. It provides guidance on the lower limits of expected weight gain for children, whatever their initial centile position. The chart's theoretical basis, the process of its construction, and its evaluation are described in this paper. Evaluation was by a self completion questionnaire, where respondents answered questions about a range of standardised growth patterns, plotted on old and new charts. Forty five health visitors, 28 general practitioner principals and registrars, and nine community paediatricians provided 328 chart ratings. These showed that the new format significantly increased the proportion of correctly rated charts (old: 45 (28%); new: 82 (51%)), with the greatest impact in severe cases. This suggests that the new chart improves the precision of judgments made about weight gain in infancy.