Reliability of motor development data in the WHO Multicentre Growth Reference Study

Aim: To describe the methods used to standardize the assessment of motor milestones in the WHO Multicentre Growth Reference Study (MGRS) and to present estimates of the reliability of the assessments.
Methods: As part of the MGRS, longitudinal data were collected on the acquisition of six motor milestones by children aged 4 to 24 mo in Ghana, India, Norway, Oman and the USA. To ensure standardized data collection, the sites conducted regular standardization sessions during which fieldworkers took turns to examine and score about 10 children for the six milestones. Assessments of the children were videotaped, and later the other fieldworkers in the same site watched the videotaped sessions and independently rated performances. The assessments were also viewed and rated by the study coordinator. The coordinator's ratings were considered the reference (true) scores. In addition, one cross-site standardization exercise took place using videotapes of 288 motor assessments. The degree of concordance between fieldworkers and the coordinator was analysed using the Kappa coefficient and the percentage of agreement.
Results: Overall, high percentages of agreement (81–100%) between fieldworkers and the coordinator and "substantial" (0.61–0.80) to "almost perfect" (>0.80) Kappa coefficients were obtained for all fieldworkers, milestones and sites. Homogeneity tests confirm that the Kappas are homogeneous across sites, across milestones, and across fieldworkers. Concordance was slightly higher in the cross-site session than in the site standardization sessions. There were no systematic differences in assessing children by direct examination or through videotapes.
Conclusion: These results show that the criteria used to define performance of the milestones were similar and applied with equally high levels of reliability among fieldworkers within a site, among milestones within a site, and among sites across milestones.     

婴幼儿体格测量培训前后对体格测量可信度的影响

目的 研究培训对儿童体格测量质量的影响。方法 采集重庆市5家城区医院被评价的测量者培训前（2010年3~10月）和培训后（2011年3~10月）婴幼儿体格指标的测量数据,同步采集派驻5家城区医院的标准测量者复测测量数据,比较培训对被评价的测量者测量数据可信度的影响。被评价的测量者和标准测量者均在正常工作状态下,进行身长、顶臀长及头围的测量并记录数据,以测量技术误差（TEM）、测量差异绝对值的均值（MAD）、可信度系数（R）、最大测量差异值（Max）和关键值内差异的百分率（PDCV）作为被评价的测量者和标准测量者可信度描述指标。结果 培训前后分别收集739名及497名婴幼儿的测量数据。标准测量者在培训前后测量的身长、顶臀长及头围数据MAD差异无统计学意义（ P>0.05）。被评价的测量者和标准测量者培训前身长、顶臀长和头围的MAD分别为0.68、0.83和0.45 cm,TEM分别为0.64、0.79和0.42 cm。培训后MAD分别为0.40、0.51和0.28 cm,TEM分别为0.38、0.46和0.25 cm,培训后身长、头围及顶臀长MAD和TEM较培训前明显减小,差异均有统计学意义。培训前被评价的测量者和标准测量者测量差异属于较好质量标准（身长、顶臀长≤0.5 cm,头围≤0.2 cm）的PDCV,身长、头围和顶臀长分别为56.2%、45.6%和34.9%,培训后分别提高至74.0%、59.7%和51.5%,差异具有统计学意义（P<0.005）。培训后被评价的测量者和标准测量者身长、顶臀长和头围仍分别有4.9%、7.9%和11.5%的测量数据属于错误数据。结论 培训后测量者对婴幼儿身长、顶臀长及头围的测量数据达到了较好的可信度标准,测量质量明显提高。     

Relationship between maternal and newborn anthropometric measurements in Sudan

Background:  The aim of the present study was to investigate the relationship between maternal and newborn anthropometry.
Methods:  In 1000 Sudanese mothers and newborns anthropometric measurements were taken within 24 h of birth. The relationship between maternal characteristics including age, years of education, social class and anthropometry, and newborn characteristics including gestational age, weight, body length, body circumference and skin-fold thickness, was investigated on multiple regression with backward selection, and multivariate anova (where appropriate) to identify the most important associations.
Results:  Maternal age and anthropometry were significantly associated with newborn anthropometry to a variable extent. The strongest associations (R² > 5–6%) were found for mid-arm circumference, supine length and birthweight. The postpartum maternal lean body mass (LBM) was significantly associated with birthweight, body length and body circumference ( P  < 0.001), while skin-fold thickness was mainly associated with maternal age and maternal body mass index (BMI). Gestational age was only weakly associated with the maternal height (R² > 1.3%) and the association between maternal anthropometry and the ponderal index (PI) of the newborn was negligible (R² < 1%). Maternal education was significantly associated with birthweight and body circumference (except the abdominal), and the PI and the latter increased significantly with increasing number of years of education. No association between social class and newborn anthropometry was obtained.
Conclusion:  There was a significant association between maternal LBM and newborn size and between maternal BMI and newborn fat stores. Maternal education and not social class was associated with newborn size.     

儿童保健专科护士体格测量数据的可信度研究

目的 分析儿童保健专科护士体格测量数据的可信度,确定专科护士测量技术质量控制标准。方法 选择重庆医科大学附属儿童医院儿童保健科健康体检的0~12岁儿童为研究对象。1名从事儿童体格测量的副主任护师为测量专家,另1名有1年以上体格测量工作经验的专科护士为对照。分别测量头围、身长（高）、顶臀长（坐高）及胸围4项体格指标1次,记录测量数据。分为<1岁、～3岁和≥3岁组。计算测量技术误差（TEM）、测量差异均值（MAD）、可信度系数（R）和组间相关系数（ICC）等可信度指标,比较不同体格指标和不同年龄组间可信度的差异。结果 2006年3～10月549名儿童完成了测量,其中<1岁组224名,～3岁198名,≥3岁127名。①头围、身长（高）、顶臀长（坐高）及胸围的MAD分别为0.17、0.35、0.49和0.64 cm;TEM分别为0.16、0.34、0.46及0.59 cm,R均为1.00,ICC为0.95~1.00。②各年龄组头围和胸围的MAD差异无统计学意义;<1岁组和≥3岁组身长（高）的MAD差异有统计学意义;<1岁、～3岁与≥3岁组顶臀长（坐高）的MAD差异有统计学意义。结论 专科护士总体测量技术较好,测量差异均在允许范围内。头围测量的可信度最高,其次是身长（身高）和顶臀长（坐高）,胸围测量不易准确。规范的测量工具、统一的测量方法及专业的测量者是体格测量数据可靠的前提。     

Assessment of differences in linear growth among populations in the WHO Multicentre Growth Reference Study

Aim: To assess differences in length/height among populations in the WHO Multicentre Growth Reference Study (MGRS) and to evaluate the appropriateness of pooling data for the purpose of constructing a single international growth standard. Methods: The MGRS collected growth data and related information from 8440 affluent children from widely differing ethnic backgrounds and cultural settings (Brazil, Ghana, India, Norway, Oman and the USA). Eligibility criteria included breastfeeding, no maternal smoking and environments supportive of unconstrained growth. The study combined longitudinal (birth to 24 mo) and cross-sectional (18–71 mo) components. For the longitudinal component, mother–infant pairs were enrolled at delivery and visited 21 times over the next 2 y. Rigorous methods of data collection and standardized procedures were applied across study sites. We evaluate the total variability of length attributable to sites and individuals, differences in length/height among sites, and the impact of excluding single sites on the percentiles of the remaining pooled sample. Results: Proportions of total variability attributable to sites and individuals within sites were 3% and 70%, respectively. Differences in length and height ranged from −0.33 to +0.49 and −0.41 to +0.46 standard deviation units (SDs), respectively, most values being below 0.2 SDs. Differences in length on exclusion of single sites ranged from −0.10 to +0.07, −0.07 to +0.13, and −0.25 to +0.09 SDs, for the 50th, 3rd and 97th percentiles, respectively. Corresponding values for height ranged from −0.09 to +0.08, −0.12 to +0.13, and −0.15 to +0.07 SDs.
Conclusion: The striking similarity in linear growth among children in the six sites justifies pooling the data and constructing a single international standard from birth to 5 y of age.     

WHO Child Growth Standards based on length/height, weight and age

Aim: To describe the methods used to construct the WHO Child Growth Standards based on length/height, weight and age, and to present resulting growth charts. Methods: The WHO Child Growth Standards were derived from an international sample of healthy breastfed infants and young children raised in environments that do not constrain growth. Rigorous methods of data collection and standardized procedures across study sites yielded very high-quality data. The generation of the standards followed methodical, state-of-the-art statistical methodologies. The Box-Cox power exponential (BCPE) method, with curve smoothing by cubic splines, was used to construct the curves. The BCPE accommodates various kinds of distributions, from normal to skewed or kurtotic, as necessary. A set of diagnostic tools was used to detect possible biases in estimated percentiles or z-score curves. Results: There was wide variability in the degrees of freedom required for the cubic splines to achieve the best model. Except for length/height-for-age, which followed a normal distribution, all other standards needed to model skewness but not kurtosis. Length-for-age and height-for-age standards were constructed by fitting a unique model that reflected the 0.7-cm average difference between these two measurements. The concordance between smoothed percentile curves and empirical percentiles was excellent and free of bias. Percentiles and z-score curves for boys and girls aged 0–60 mo were generated for weight-for-age, length/height-for-age, weight-for-length/height (45 to 110 cm and 65 to 120 cm, respectively) and body mass index-for-age.
Conclusion: The WHO Child Growth Standards depict normal growth under optimal environmental conditions and can be used to assess children everywhere, regardless of ethnicity, socio-economic status and type of feeding.     

Breastfeeding in the WHO Multicentre Growth Reference Study

Aim: To document how children in the WHO Multicentre Growth Reference Study (MGRS) complied with feeding criteria and describe the breastfeeding practices of the compliant group.
Methods: The MGRS longitudinal component followed 1743 mother–infant pairs from birth to 24 mo in six countries (Brazil, Ghana, India, Norway, Oman and the USA). The study included three criteria for compliance with recommended feeding practices that were monitored at each follow-up visit through food frequency reports and 24-h dietary recalls. Trained lactation counsellors visited participating mothers frequently in the first months after delivery to help with breastfeeding initiation and prevent and resolve lactation problems.
Results: Of the 1743 enrolled newborns, 903 (51.8%) completed the follow-up and complied with the three feeding criteria. Three quarters (74.7%) of the infants were exclusively/predominantly breastfed for at least 4 mo, 99.5% were started on complementary foods by 6 mo of age, and 68.3% were partially breastfed until at least age 12 mo. Compliance varied across sites (lowest in Brazil and highest in Ghana) based on their initial baseline breastfeeding levels and sociocultural characteristics. Median breastfeeding frequency among compliant infants was 10, 9, 7 and 5 feeds per day at 3, 6, 9 and 12 mo, respectively. Compliant mothers were less likely to be employed, more likely to have had a vaginal delivery, and fewer of them were primiparous. Pacifier use was more prevalent in the non-compliant group.
Conclusion: The MGRS lactation support teams were successful in enhancing breastfeeding practices and achieving high rates of compliance with the feeding criteria required for the construction of the new growth standards.     

Enrolment and baseline characteristics in the WHO Multicentre Growth Reference Study

Aim: To describe the WHO Multicentre Growth Reference Study (MGRS) sample with regard to screening, recruitment, compliance, sample retention and baseline characteristics.
Methods: A multi-country community-based study combining a longitudinal follow-up from birth to 24 mo with a cross-sectional survey of children aged 18 to 71 mo. Study subpopulations had to have socio-economic conditions favourable to growth, low mobility and ≥ 20% of mothers practising breastfeeding. Individual inclusion criteria were no known environmental constraints on growth, adherence to MGRS feeding recommendations, no maternal smoking, single term birth and no significant morbidity. For the longitudinal sample, mothers and newborns were screened and enrolled at birth and visited 21 times at home until age 24 mo.
Results: About 83% of 13 741 subjects screened for the longitudinal component were ineligible and 5% refused to participate. Low socio-economic status was the predominant reason for ineligibility in Brazil, Ghana, India and Oman, while parental refusal was the main reason for non-participation in Norway and USA. Overall, 88.5% of enrolled subjects completed the 24-mo follow-up, and 51% (888) complied with the MGRS feeding and no-smoking criteria. For the cross-sectional component, 69% of 21 510 subjects screened were excluded for similar reasons as for the longitudinal component. Although low birthweight was not an exclusion criterion, its prevalence was low (2.1% and 3.2% in the longitudinal and cross-sectional samples, respectively). Parental education was high, between 14 and 15 y of education on average.
Conclusion: The MGRS criteria were effective in selecting healthy children with comparable affluent backgrounds across sites and similar characteristics between longitudinal and cross-sectional samples within sites.     

Body composition in neonates: relationship between measured and derived anthropometry with dual-energy X-ray absorptiometry measurements

This study examined the relationship between measured and derived anthropometric measurements with dual-energy X-ray absorptiometry measured lean and fat mass at 3.0 +/- 2.8 (SD) days in 120 neonates with birth weights appropriate (AGA; n=74), large (LGA; n=30); or small (SGA, n=16) for gestational age. Anthropometric measurements, including total body weight and length, and regional measurements, including circumferences of head, chest, abdomen, midarm, and midthigh and dynamic skinfold thickness (15 and 60 s) at tricep, subscapular, suprailiac, and midthigh, were performed. Derived anthropometry included muscle and fat areas, and ratios were calculated from direct measurements. The skinfold thickness measurements between 15 and 60 s were highly correlated (r=0.973-0.996, p <0.001 for all comparisons). Strong correlations existed within the four circumferences of trunk and extremities, the four skinfolds, and the ratios of weight to length and its higher powers. Weight and length accounted for >97% of the variance of lean mass in AGA and SGA infants and 46% of the variance in LGA infants and for 80, 82, and 84% of the variance of fat mass in SGA, AGA, and LGA infants, respectively, whereas midarm:head circumference ratio and arm muscle and fat areas are the most important derived anthropometry in the prediction for body composition. They independently accounted for up to 16.5 and 10.2%, respectively, of the variance in body composition depending on the state of in utero growth. Thus, total body weight and length and some selected regional and derived anthropometry accounted for the vast majority of the variance of body composition.     

Evidence of genetic regulation of fetal longitudinal growth

BACKGROUND: Genetic as well as environmental factors are important determinants of fetal growth but there have been few studies of the influence of paternal factors on fetal growth. AIM: To study the influence of paternal anthropometry on detailed measurements of offspring at birth. DESIGN: A prospective cohort study involving biochemistry, and anthropometry, of mothers and fathers at 28 weeks gestation, and detailed anthropometry of children within 24 h of birth. SUBJECTS: 567 White Caucasian singleton, non-diabetic, full term pregnancies recruited from central Exeter, UK. RESULTS: Paternal height, but not paternal BMI, was correlated with birth weight (r = 0.19) and with birth length (r = 0.33). This was independent of potential confounders and maternal height. All measurements of fetal skeletal growth including crown-rump, knee-heel and head circumference were associated with paternal height. Maternal height showed similar correlations with birth weight (r = 0.18) and birth length (r = 0.26). Maternal BMI was correlated with birth weight (r = 0.27) and birth length (r = 0.15). In a multifactorial analysis 38% of the variance in fetal height could be explained by gestation, sex, paternal height, maternal height, maternal glucose, maternal BMI, parity and maternal smoking. CONCLUSION: Paternal height has an independent influence on size at birth. This predominantly influences length and skeletal growth of the baby. In contrast to maternal obesity the degree of paternal obesity does not influence birth weight. This work suggests that there is genetic regulation of skeletal growth while the maternal environment predominantly alters the adiposity of the fetus.     

The reliability of weight‐for‐length/height Z scores in children

The World Health Organisation (WHO) recommends weight‐for‐length/height (WFL/H), represented as a Z score for diagnosing acute malnutrition among children aged 0 to 60 months. Under controlled conditions, weight, height and length measurements have high degree of reliability. However, the reliability when combined into a WFL/H Z score, in all settings is unclear. We conducted a systematic review of published studies assessing the reliability of WFL/Hz on PubMed and Google scholar. Studies were included if they presented reliability scores for the derived index of WFL/Hz, for children under 5 years. Meta‐analysis was conducted for a pooled estimate of reliability overall, and for children above and below 24 months old. Twenty six studies on reliability of anthropometry were identified but only three, all community‐based studies, reported reliability scores for WFL/Hz. The overall pooled intra‐class correlation coefficient (ICC) estimate for WFL/Hz among children aged 0 to 60 months was 0.81 (95% CI 0.64 to 0.99). Among children aged less than 24 months the pooled ICC estimate from two studies was 0.72 (95% CI 0.67 to 0.77) while the estimate reported for children above 24 months from one study was 0.97 (95% CI 0.97 to 0.99). Although WFL/Hz is recommended for diagnosis of acute under nutrition among children below 5 years, information on its reliability in all settings is sparse. In community settings, reliability of WFL/Hz is considerably lower than for absolute measures of weight and length/height, especially in younger children. The reliability of WFL/Hz needs further evaluation.     

A comparison of three infant skinfold reference standards: Tanner–Whitehouse,Cambridge Infant Growth Study,and WHO Child Growth Standards

As researchers increasingly focus on early infancy as a critical period of development, there is a greater need for methodological tools that can address all aspects of infant growth. Infant skinfold measures, in particular, are measurements in need of reliable reference standards that encompass all ages of infants and provide an accurate assessment of the relative fatness of a population. This report evaluates three published reference standards for infant skinfold measurements: Tanner–Whitehouse, Cambridge Infant Growth Study, and the World Health Organization (WHO) Child Growth Standards. To assess these standards, triceps skinfolds from a population of rural Kenyan infants (n = 250) and triceps skinfolds and subscapular skinfolds from infants in the National Health and Nutrition Examination Survey 1999–2002 (NHANES; n = 1197) were calculated as z‐scores from the lambda‐mu‐sigma curves provided by each reference population. The Tanner–Whitehouse standards represented both the Kenyan and US populations as lean, while the Cambridge standards represented both populations as overfat. The distribution of z‐scores based on the WHO standards fell in the middle, but excluded infants from both populations who were below the age of 3 months. Based on these results, the WHO reference standard is the best skinfold reference standard for infants over the age of 3 months. For populations with infants of all ages, the Tanner–Whitehouse standards are recommended, despite representing both study populations as underfat. Ideally, the WHO will extend their reference standard to include infants between the ages of 0 and 3 months.     

Physical growth of pre-pubertal Punjabi girls

Summary and Abstract Cross-sectional data on 724 pre-pubertal Punjabi girls ranging in age from 6 to 12 years, were collected from the primary sections of various schools of Patiala city during 1974. Children belonging to the lower and lower-middle socio-economic groups were included in the present study. Nine anthropometric measurements including three skinfolds were taken on each subject. Statistical constants like mean, standard deviation and standard error of mean have been calculated. Growth standards of girls in terms of percentiles for these age groups have been constructed for some selected measurements. The resluts show that the velocity of weight increases in the successive ages up to 10–11 years. All other anthropometric measurements excluding skinfolds, show a general trend of decline in the rate of growth of body measurements up to 10–11 years. The girls ef this sample seem to pick up accelerated growth during the 11–12 year age interval to enter the adolescent growth spurt. The pattern of change of subcutaneous tissue provides two types of pictures-suprailiac and subscapular skinfolds show continuous increase during the period under study whereas the triceps skinfold decreases up to 9 years and again increases. The velocity curves of the skinfolds do not indicate any appreciable trend of increase or decrease. Linear regression equations were fitted to height, weight, log weight, and sitting height measurements. It is noticed that log weight measurements provide a better fit upon age than the weight measurements taken as such. From the Department of Human Biology, Punjabi University, Patiata.     

乌鲁木齐市7岁以下维、汉族儿童体格发育调查

目的 调查乌鲁木齐市0～6岁维、汉族儿童生长发育现状,为提高儿童健康水平提供理论依据.方法 用整群随机抽样方法,调查乌鲁木齐市7区1县0～6岁维、汉族儿童体格发育状况,包括体重、身高、坐高、头围、胸围5项指标;用Z评分法评价0～6岁儿童体格发育状况.结果 0～6岁维、汉族儿童各项生长指标随年龄增长而增长,以小年龄组增长最快;同年龄的男童体重、身高均值大于女童;同年龄、同性别维、汉族儿童体重和身高之间差异无统计学意义,其余生长发育指标差别有统计学意义.乌鲁术齐市维、汉儿童体重、身高均值达到世界卫生组织颁布的标准.结论 乌鲁木齐市维、汉族儿童生长发育存在性别和民族差异,生长发育水平与2005年九市城区儿童体格发育相当,达到2006年世界卫生组织颁布的儿童生长标准.     

The anabolic steroid oxandrolone increases muscle mass in prepubertal boys with constitutional delay of growth.

The aim of this study was to investigate the effect of oxandrolone on body composition in boys with constitutional delay of growth and puberty. In 14 prepubertal boys, height, weight, triceps and subscapular skinfolds and upper arm circumference were measured. Body mass index, the ratio of subscapular to triceps skinfolds and the upper muscle area were also determined. The difference of the various measurements and indices, 3 to 6 months before and after commencement of oxandrolone treatment, were calculated, while the boys remained prepubertal. We observed a marked increase in body mass index, a decrease of triceps and subscapular skinfolds, an increase in the ratio of subscapular to triceps skinfolds and also an increase in upper muscle area after the onset of oxandrolone treatment. These results suggest that low dose oxandrolone administration in prepubertal boys with constitutional growth delay causes a disproportionate increase of weight to height which is largely due to increased body muscle.     

Blood pressure measurement in preschool children: The Hisayama study

Objective: To establish the blood pressure (BP) measurement protocol for Japanese preschool children, systolic BP (K1) and diastolic BP (K4, K5) were measured along with anthropometric values.
Methodology: Commercially available mercury sphygmomanometers were used. In the first group of children (group A), BP was measured in 79 boys and 85 girls using a cuff 9 cm wide and 23 cm long. In the second group (group B), the length and circumference of the upper right arm of 147 boys and 139 girls were measured to select cuffs appropriate for their sizes. Blood pressure measurements were performed twice on the right arm of the children in the seated position at a mean interval of 5 min.
Results: There were no significant differences in the anthropometric values (height, bodyweight, body mass index [BMI], length and circumference of the upper arm) between groups A and B. The BP values at K1, K4 and K5 in the first measurement of group B were 91 ± 9, 54 ± 8, and 48 ± 10 mmHg (boys) and 90 ± 9, 54 ± 8, and 48 ± 12 mmHg (girls), respectively. There were no significant differences between the first and second measurements in both groups, however, there were significant differences in the first and second measurements of K4 between groups A and B. Multiple regression analysis by the stepwise method revealed a strong correlation between K1 and the length of the upper arm in the boys and the bodyweight in the girls: between K4 and the bodyweight in the boys and the BMI in the girls, and between K5 and the height in the boys and the upper arm circumference in the girls.
Conclusions: From these results it would appear that a single measurement is sufficient under appropriate measurement conditions such as rest before measurement and the choice of the cuff size according to the upper arm circumference, and that BP is closely correlated with the anthropometric values in preschool children.     

The "Lasso-o" tape: stretchability and observer variability in head circumference measurement

Head circumference is an important clinical measurement in children. The stretchability of the Lasso-o tape and the intra- and inter-observer reproducibility of measurements using it were investigated. Old Lasso-o tapes stretch significantly. The intra-class coefficients were 0.999 for intra-observer and 0.979 for inter-observer measurements. Nonetheless in 9% of measurements inter-observer variability was over 1 cm.     

The "Lasso-o" tape: stretchability and observer variability in head circumference measurement.

Head circumference is an important clinical measurement in children. The stretchability of the Lasso-o tape and the intra- and inter-observer reproducibility of measurements using it were investigated. Old Lasso-o tapes stretch significantly. The intra-class coefficients were 0.999 for intra-observer and 0.979 for inter-observer measurements. Nonetheless in 9% of measurements inter-observer variability was over 1 cm.     

Anthropometric measurements and physical characteristics in the assessment of neonatal maturity

Summary 800 singly born normal newborn infants were studied for their anthropometry. All the physical measurements tended to be lower than those for their Western counterparts. Out of 651 infants born after 37 weeks of gestation, 25.34 per cent weighed 2500 G. or less; 18.12 per cent had a crown heel length less than 47 cm.; 91.24 per cent had a crown rump length less than 32 cm., 14.44 per cent had a head circumference less than 33 cm. and 12.3 per cent had a chest circumference less than 30 cm.