International values for haemoglobin distributions in healthy pregnant women

BACKGROUND

Anaemia in pregnancy is a global health problem with associated morbidity and mortality.

METHODS

A secondary analysis of prospective, population-based study from 2009 to 2016 to generate maternal haemoglobin normative centiles in uncomplicated pregnancies in women receiving optimal antenatal care. Pregnant women were enrolled <14 weeks' gestation in the Fetal Growth Longitudinal Study (FGLS) of the INTERGROWTH-21st Project which involved eight geographically diverse urban areas in Brazil, China, India, Italy, Kenya, Oman, United Kingdom and United States. At each 5 ± 1 weekly visit until delivery, information was collected about the pregnancy, as well as the results of blood tests taken as part of routine antenatal care that complemented the study's requirements, including haemoglobin values.

FINDINGS

A total of 3502 (81%) of 4321 women who delivered a live, singleton newborn with no visible congenital anomalies, contributed at least one haemoglobin value. Median haemoglobin concentrations ranged from 114.6 to 121.4 g/L, 94 to 103 g/L at the 3rd centile, and from 135 to 141 g/L at the 97th centile. The lowest values were seen between 31 and 32 weeks' gestation, representing a mean drop of 6.8 g/L compared to 14 weeks' gestation. The percentage variation in maternal haemoglobin within-site was 47% of the total variance compared to 13% between sites.

INTERPRETATION

We have generated International, gestational age-specific, smoothed centiles for maternal haemoglobin concentration compatible with better pregnancy outcomes, as well as adequate neonatal and early childhood morbidity, growth and development up to 2 years of age.

FUNDING

Bill & Melinda Gates Foundation Grant number 49038.

National, regional, and worldwide estimates of low birthweight in 2015, with trends from 2000: a systematic analysis

Background

Low birthweight (LBW) of less than 2500 g is an important marker of maternal and fetal health, predicting mortality, stunting, and adult-onset chronic conditions. Global nutrition targets set at the World Health Assembly in 2012 include an ambitious 30% reduction in LBW prevalence between 2012 and 2025. Estimates to track progress towards this target are lacking; with this analysis, we aim to assist in setting a baseline against which to assess progress towards the achievement of the World Health Assembly targets.

Methods

We sought to identify all available LBW input data for livebirths for the years 2000–16. We considered population-based national or nationally representative datasets for inclusion if they contained information on birthweight or LBW prevalence for livebirths. A new method for survey adjustment was developed and used. For 57 countries with higher quality time-series data, we smoothed country-reported trends in birthweight data by use of B-spline regression. For all other countries, we estimated LBW prevalence and trends by use of a restricted maximum likelihood approach with country-level random effects. Uncertainty ranges were obtained through bootstrapping. Results were summed at the regional and worldwide level.

Findings

We collated 1447 country-years of birthweight data (281 million births) for 148 countries of 195 UN member states (47 countries had no data meeting inclusion criteria). The estimated worldwide LBW prevalence in 2015 was 14·6% (uncertainty range [UR] 12·4–17·1) compared with 17·5% (14·1–21·3) in 2000 (average annual reduction rate [AARR] 1·23%). In 2015, an estimated 20·5 million (UR 17·4–24·0 million) livebirths were LBW, 91% from low-and-middle income countries, mainly southern Asia (48%) and sub-Saharan Africa (24%).

Interpretation

Although these estimates suggest some progress in reducing LBW between 2000 and 2015, achieving the 2·74% AARR required between 2012 and 2025 to meet the global nutrition target will require more than doubling progress, involving both improved measurement and programme investments to address the causes of LBW throughout the lifecycle.

Funding

Bill & Melinda Gates Foundation, The Children's Investment Fund Foundation, United Nations Children's Fund (UNICEF), and WHO.

Growth Status, Inflammation, and Enteropathy in Young Children in Northern Tanzania

Recent evidence suggests that enteropathy of the gut due to environmental conditions (i.e., environmental enteropathy [EE]) in young children is negatively associated with linear growth. Using a case-control study design, we examined the potential determinants of stunting in stunted and non-stunted children 22-28 months of age. Potential determinants included inflammation biomarkers C-reactive protein, alpha-1-acid glycoprotein (AGP), and endotoxin-core antibody (EndoCAb) measured in serum samples; enteropathy markers alpha-1-antitrypsin, neopterin, myeloperoxidase (MPO) measured in stools samples; and demographic, health, feeding, and household characteristics. We also explored the determinants of EE by testing associations of composite EE scores and individual biomarkers with potential risk factors. Fifty-two percent of children (n = 310) were found to be stunted, and mean height-for-age Z scores (HAZ) were -1.22 (standard deviation [SD] ± 0.56) among non-stunted (control) children and -2.82 (SD ± 0.61) among stunted (case) children. Child HAZ was significantly (P < 0.05) and inversely associated with AGP, and child stunting was significantly positively associated (P < 0.05) with low dietary diversity, severe household hunger, and absence of soap in the household. Alpha-1-acid glycoprotein and EndoCAb concentrations were also significantly higher (P < 0.05) among children in households with no soap. Our study documented a seemingly localized cultural practice of young children (25%) being fed their dirty bathwater, which was associated with significantly higher concentrations of MPO (P < 0.05). Alpha-1-acid glycoprotein showed the most consistent associations with child growth and hygiene practices, but fecal EE biomarkers were not associated with child growth. The lack of retrospective data in our study may explain the null findings related to fecal EE biomarkers and child growth.

Anthropometric Reference Data for International Use: Recommendations from a who Expert Committee

The World Health Organization (WHO) convened an Expert Committee to re-evaluate the use of anthropometry at different ages for assessing health, nutrition, and social well-being. The Committee's task included identifying reference data for anthropometric indices when appropriate, and providing guidelines on how the data should be used. For foetal growth, the Committee recommended an existing sex-specific multiracial reference. In view of the significant technical drawbacks of the current National Center for Health Statistics (NCHS)/WHO reference and its inadequacy for assessing the growth of breastfed infants, the Committee recommended the development of a new reference concerning weight and length/height for infants and children, which will be a complex and costly undertaking. Proper interpretation of mid-upper-arm circumference for pre-schoolers requires age-specific reference data. To evaluate adolescent height-for-age, the Committee recommended the current NCHS/WHO reference. Use of the NCHS body mass index (BMI) data, with their upper percentile elevations and skewness, is undesirable for setting health goals; however, these data were provisionally recommended for defining obesity based on a combination of elevated BMI and high subcutaneous fat. The NCHS values were provisionally recommended as reference data for subscapular and triceps skinfold thicknesses. Guidelines were also provided for adjusting adolescent anthropometric comparisons for maturational status. Currently, there is no need for adult reference data for BMI; interpretation should be based on pragmatic BMI cut-offs. Finally, the Committee noted that few normative anthropometric data exist for the elderly, especially for those over 80 years of age. Proper definitions of health status, function, and biologic age remain to be developed for this group.

Measurement and Standardization Protocols for Anthropometry Used in the Construction of a New International Growth Reference

The objective of the Motor Development Study was to describe the acquisition of selected gross motor milestones among affluent children growing up in different cultural settings. This study was conducted in Ghana, India, Norway, Oman, and the United States as part of the longitudinal component of the World Health Organization (WHO) Multicentre Growth Reference Study (MGRS). Infants were followed from the age of four months until they could walk independently. Six milestones that are fundamental to acquiring self-sufficient erect locomotion and are simple to evaluate were assessed: sitting without support, hands-and-knees crawling, standing with assistance, walking with assistance, standing alone, and walking alone. The information was collected by both the children's caregivers and trained MGRS fieldworkers. The caregivers assessed and recorded the dates when the milestones were achieved for the first time according to established criteria. Using standardized procedures, the fieldworkers independently assessed the motor performance of the children and checked parental recording at home visits. To ensure standardized data collection, the sites conducted regular standardization sessions. Data collection and data quality control took place simultaneously. Data verification and cleaning were performed until all queries had been satisfactorily resolved.

Assessment of Gross Motor Development in the who Multicentre Growth Reference Study

The World Health Organization (WHO) Multicentre Growth Reference (MGRS) data management protocol was designed to create and manage a large data bank of information collected from multiple sites over a period of several years. Data collection and processing instruments were prepared centrally and used in a standardized fashion across sites. The data management system contained internal validation features for timely detection of data errors, and its standard operating procedures stipulated a method of master file updating and correction that maintained a clear trail for data auditing purposes. Each site was responsible for collecting, entering, verifying, and validating data, and for creating site-level master files. Data from the sites were sent to the MGRS Coordinating Centre every month for master file consolidation and more extensive quality control checking. All errors identified at the Coordinating Centre were communicated to the site for correction at source. The protocol imposed transparency on the sites' data management activities but also ensured access to technical help with operation and maintenance of the system. Through the rigorous implementation of what has been a highly demanding protocol, the MGRS has accumulated a large body of very high-quality data.

Members of the who Multicentre Growth Reference Study Group

The World Health Organization (WHO) Multicentre Growth Reference Study (MGRS) is a community-based, multicountry project to develop new growth references for infants and young children. The design combines a longitudinal study from birth to 24 months with a cross-sectional study of children aged 18 to 71 months. The pooled sample from the six participating countries (Brazil, Ghana, India, Norway, Oman, and the United States) consists of about 8,500 children. The study subpopulations had socioeconomic conditions favorable to growth, and low mobility, with at least 20% of mothers following feeding recommendations and having access to breastfeeding support. The individual inclusion criteria were absence of health or environmental constraints on growth, adherence to MGRS feeding recommendations, absence of maternal smoking, single term birth, and absence of significant morbidity. In the longitudinal study, mothers and newborns were screened and enrolled at birth and visited at home 21 times: at weeks 1, 2, 4, and 6; monthly from 2 to 12 months; and every 2 months in their second year. In addition to the data collected on anthropometry and motor development, information was gathered on socioeconomic, demographic, and environmental characteristics, perinatal factors, morbidity, and feeding practices. The prescriptive approach taken is expected to provide a single international reference that represents the best description of physiological growth for all children under five years of age and to establish the breastfed infant as the normative model for growth and development.

Anemia, Micronutrient Deficiencies, and Malaria in Children and Women in Sierra Leone Prior to the Ebola Outbreak - Findings of a Cross-Sectional Study

To identify the factors associated with anemia and to document the severity of micronutrient deficiencies, malaria and inflammation, a nationally representative cross-sectional survey was conducted. A three-stage sampling procedure was used to randomly select children <5 years of age and adult women from households in two strata (urban and rural). Household and individual data were collected, and blood samples from children and women were used to measure the prevalence of malaria, inflammation, and deficiencies of iron, vitamin A, folate, and vitamin B12. 839 children and 945 non-pregnant women were included in the survey. In children, the prevalence rates of anemia (76.3%; 95% CI: 71.8, 80.4), malaria (52.6%; 95% CI: 46.0, 59.0), and acute and chronic inflammation (72.6%; 95% CI: 67.5, 77.1) were high. However, the prevalence of vitamin A deficiency (17.4%; 95% CI: 13.9, 21.6) was moderate, and the prevalence of iron deficiency (5.2%; 95% CI: 3.3, 8.1) and iron-deficiency anemia (3.8%; 95% CI: 2.5, 5.8) were low. Malaria and inflammation were associated with anemia, yet they explained only 25% of the population-attributable risk. In women, 44.8% (95% CI: 40.1, 49.5), 35.1% (95% CI: 30.1, 40.4), and 23.6% (95% CI: 20.4, 27.3) were affected by anemia, malaria, or inflammation, respectively. The prevalence rates of iron deficiency (8.3%; 95% CI: 6.2, 11.1), iron-deficiency anemia (6.1%; 95% CI: 4.4, 8.6), vitamin A deficiency (2.1%; 95% CI: 1.1, 3.1) and vitamin B12 deficiency (0.5%; 95% CI: 0.2, 1.4) were low, while folate deficiency was high (79.2%; 95% CI: 74.1, 83.5). Iron deficiency, malaria, and inflammation were significantly associated with anemia, but explained only 25% of cases of anemia. Anemia in children and women is a severe public health problem in Sierra Leone. Since malaria and inflammation only contributed to 25% of anemia, other causes of anemia, such as hemoglobinopathies, should also be explored.

Childhood stunting: a global perspective

Childhood stunting is the best overall indicator of children's well-being and an accurate reflection of social inequalities. Stunting is the most prevalent form of child malnutrition with an estimated 161 million children worldwide in 2013 falling below -2 SD from the length-for-age/height-for-age World Health Organization Child Growth Standards median. Many more millions suffer from some degree of growth faltering as the entire length-for-age/height-for-age z-score distribution is shifted to the left indicating that all children, and not only those falling below a specific cutoff, are affected. Despite global consensus on how to define and measure it, stunting often goes unrecognized in communities where short stature is the norm as linear growth is not routinely assessed in primary health care settings and it is difficult to visually recognize it. Growth faltering often begins in utero and continues for at least the first 2 years of post-natal life. Linear growth failure serves as a marker of multiple pathological disorders associated with increased morbidity and mortality, loss of physical growth potential, reduced neurodevelopmental and cognitive function and an elevated risk of chronic disease in adulthood. The severe irreversible physical and neurocognitive damage that accompanies stunted growth poses a major threat to human development. Increased awareness of stunting's magnitude and devastating consequences has resulted in its being identified as a major global health priority and the focus of international attention at the highest levels with global targets set for 2025 and beyond. The challenge is to prevent linear growth failure while keeping child overweight and obesity at bay.

Assessment of the WHO Stunting Framework using Ethiopia as a case study

Poor linear growth in children <5 years old, or stunting, is a serious public health problem particularly in Sub-Saharan Africa. In 2013, the World Health Organization (WHO) released a conceptual framework on the Context, Causes and Consequences of Childhood Stunting (the 'WHO framework') that identifies specific and general factors associated with stunting. The framework is based upon a global review of data, and we have applied it to a country-level analysis where health and nutrition policies are made and public health and nutrition data are collected. We reviewed the literature related to sub-optimal linear growth, stunting and birth outcomes in Ethiopia as a case study. We found consistent associations between poor linear growth and indicators of birth size, recent illness (e.g. diarrhoea and fever), maternal height and education. Other factors listed as causes in the framework such as inflammation, exposure to mycotoxins and inadequate feeding during and after illness have not been examined in Ethiopia, and the existing literature suggests that these are clear data gaps. Some factors associated with poor linear growth in Ethiopia are missing in the framework, such as household characteristics (e.g. exposure to indoor smoke). Examination of the factors included in the WHO framework in a country setting helps identifying data gaps helping to target further data collection and research efforts. © 2016 John Wiley & Sons Ltd.

Iodine Status of Women of Reproductive Age in Sierra Leone and Its Association with Household Coverage with Adequately Iodized Salt

Salt iodization programs are a public health success in tackling iodine deficiency. Yet, a large proportion of the world's population remains at risk for iodine deficiency. In a nationally representative cross-sectional survey in Sierra Leone, household salt samples and women's urine samples were quantitatively analyzed for iodine content. Salt was collected from 1123 households, and urine samples from 817 non-pregnant and 154 pregnant women. Household coverage with adequately iodized salt (≥15 mg/kg iodine) was 80.7%. The median urinary iodine concentration (UIC) of pregnant women was 175.8 µg/L and of non-pregnant women 190.8 µg/L. Women living in households with adequately iodized salt had higher median UIC (for pregnant women: 180.6 µg/L vs. 100.8 µg/L, respectively, p < 0.05; and for non-pregnant women: 211.3 µg/L vs. 97.8 µg/L, p < 0.001). Differences in UIC by residence, region, household wealth, and women's education were much smaller in women living in households with adequately iodized salt than in households without. Despite the high household coverage of iodized salt in Sierra Leone, it is important to reach the 20% of households not consuming adequately iodized salt. Salt iodization has the potential for increasing equity in iodine status even with the persistence of other risk factors for deficiency.

Successive 1-Month Weight Increments in Infancy Can Be Used to Screen for Faltering Linear Growth

BACKGROUND

Linear growth faltering in the first 2 y contributes greatly to a high stunting burden, and prevention is hampered by the limited capacity in primary health care for timely screening and intervention.

OBJECTIVE

This study aimed to determine an approach to predicting long-term stunting from consecutive 1-mo weight increments in the first year of life.

METHODS

By using the reference sample of the WHO velocity standards, the analysis explored patterns of consecutive monthly weight increments among healthy infants. Four candidate screening thresholds of successive increments that could predict stunting were considered, and one was selected for further testing. The selected threshold was applied in a cohort of Bangladeshi infants to assess its predictive value for stunting at ages 12 and 24 mo.

RESULTS

Between birth and age 12 mo, 72.6% of infants in the WHO sample tracked within 1 SD of their weight and length. The selected screening criterion ("event") was 2 consecutive monthly increments below the 15th percentile. Bangladeshi infants were born relatively small and, on average, tracked downward from approximately age 6 to <24 mo (51% stunted). The population-attributable risk of stunting associated with the event was 14% at 12 mo and 9% at 24 mo. Assuming the screening strategy is effective, the estimated preventable proportion in the group who experienced the event would be 34% at 12 mo and 24% at 24 mo.

CONCLUSIONS

This analysis offers an approach for frontline workers to identify children at risk of stunting, allowing for timely initiation of preventive measures. It opens avenues for further investigation into evidence-informed application of the WHO growth velocity standards.

The Global Nutrition Report 2014: actions and accountability to accelerate the world's progress on nutrition

In 2013, the Nutrition for Growth Summit called for a Global Nutrition Report (GNR) to strengthen accountability in nutrition so that progress in reducing malnutrition could be accelerated. This article summarizes the results of the first GNR. By focusing on undernutrition and overweight, the GNR puts malnutrition in a new light. Nearly every country in the world is affected by malnutrition, and multiple malnutrition burdens are the "new normal." Unfortunately, the world is off track to meet the 2025 World Health Assembly (WHA) targets for nutrition. Many countries are, however, making good progress on WHA indicators, providing inspiration and guidance for others. Beyond the WHA goals, nutrition needs to be more strongly represented in the Sustainable Development Goal (SDG) framework. At present, it is only explicitly mentioned in 1 of 169 SDG targets despite the many contributions improved nutritional status will make to their attainment. To achieve improvements in nutrition status, it is vital to scale up nutrition programs. We identify bottlenecks in the scale-up of nutrition-specific and nutrition-sensitive approaches and highlight actions to accelerate coverage and reach. Holding stakeholders to account for delivery on nutrition actions requires a well-functioning accountability infrastructure, which is lacking in nutrition. New accountability mechanisms need piloting and evaluation, financial resource flows to nutrition need to be made explicit, nutrition spending targets should be established, and some key data gaps need to be filled. For example, many UN member states cannot report on their WHA progress and those that can often rely on data >5 y old. The world can accelerate malnutrition reduction substantially, but this will require stronger accountability mechanisms to hold all stakeholders to account.

Indicators linking health and sustainability in the post-2015 development agenda

The UN-led discussion about the post-2015 sustainable development agenda provides an opportunity to develop indicators and targets that show the importance of health as a precondition for and an outcome of policies to promote sustainable development. Health as a precondition for development has received considerable attention in terms of achievement of health-related Millennium Development Goals (MDGs), addressing growing challenges of non-communicable diseases, and ensuring universal health coverage. Much less attention has been devoted to health as an outcome of sustainable development and to indicators that show both changes in exposure to health-related risks and progress towards environmental sustainability. We present a rationale and methods for the selection of health-related indicators to measure progress of post-2015 development goals in non-health sectors. The proposed indicators show the ancillary benefits to health and health equity (co-benefits) of sustainable development policies, particularly those to reduce greenhouse gas emissions and increase resilience to environmental change. We use illustrative examples from four thematic areas: cities, food and agriculture, energy, and water and sanitation. Embedding of a range of health-related indicators in the post-2015 goals can help to raise awareness of the probable health gains from sustainable development policies, thus making them more attractive to decision makers and more likely to be implemented than before.

Introducing infant and young child feeding indicators into national nutrition surveillance systems: lessons from Vietnam

A comprehensive set of infant and young child feeding (IYCF) indicators for international use was published in 2008. We describe the process followed to incorporate these indicators into Vietnam's National Nutrition Surveillance System (NNSS). Following its establishment in 1980, the National Institute of Nutrition introduced the Vietnam NNSS to provide an evidence base for nutrition interventions. While anthropometric indicators based on international standards were regularly used for programme purposes, data on IYCF could not be collected with similar rigor until 2010. In 2009, with support from Alive & Thrive and UNICEF, the NNSS questionnaire was reviewed and additional content incorporated to measure IYCF practices. The tool was pilot-tested in 10 provinces and revised before nationwide roll-out in 2010.The tool comprises four pages, the first three of which focus on collecting data relating to maternal nutrition and IYCF. The last page is flexibly designed to incorporate planners' data requests for other relevant activities (e.g. mass media interventions, food security). Once analysed, the data are presented in a report comprising provincial profiles and maps illustrating IYCF practices. Importantly, the IYCF data have been used for policy advocacy (e.g. maternity leave legislation, advertisement law), programme planning, trend monitoring and capacity building. Adoption of the IYCF indicators was successful due to strategic timing, a phased approach, buy-in from stakeholders and capacity building at all levels to ensure the quality and use of data. Further revisions to the NNSS (e.g. sampling methodology, quality assurance systems) will be important to ensure the reliability of indicators.

The World Health Organization's global target for reducing childhood stunting by 2025: rationale and proposed actions

In 2012, the World Health Organization adopted a resolution on maternal, infant and young child nutrition that included a global target to reduce by 40% the number of stunted under-five children by 2025. The target was based on analyses of time series data from 148 countries and national success stories in tackling undernutrition. The global target translates to a 3.9% reduction per year and implies decreasing the number of stunted children from 171 million in 2010 to about 100 million in 2025. However, at current rates of progress, there will be 127 million stunted children by 2025, that is, 27 million more than the target or a reduction of only 26%. The translation of the global target into national targets needs to consider nutrition profiles, risk factor trends, demographic changes, experience with developing and implementing nutrition policies, and health system development. This paper presents a methodology to set individual country targets, without precluding the use of others. Any method applied will be influenced by country-specific population growth rates. A key question is what countries should do to meet the target. Nutrition interventions alone are almost certainly insufficient, hence the importance of ongoing efforts to foster nutrition-sensitive development and encourage development of evidence-based, multisectoral plans to address stunting at national scale, combining direct nutrition interventions with strategies concerning health, family planning, water and sanitation, and other factors that affect the risk of stunting. In addition, an accountability framework needs to be developed and surveillance systems strengthened to monitor the achievement of commitments and targets.

Parental height and child growth from birth to 2 years in the WHO Multicentre Growth Reference Study

Linear growth from birth to 2 years of children enrolled in the World Health Organization Multicentre Growth Reference Study was similar despite substantial parental height differences among the six study sites. Within-site variability in child length attributable to parental height was estimated by repeated measures analysis of variance using generalized linear models. This approach was also used to examine relationships among selected traits (e.g. breastfeeding duration and child morbidity) and linear growth between 6 and 24 months of age. Differences in intergenerational adult heights were evaluated within sites by comparing mid-parental heights (average of the mother's and father's heights) to the children's predicted adult height. Mid-parental height consistently accounted for greater proportions of observed variability in attained child length than did either paternal or maternal height alone. The proportion of variability explained by mid-parental height ranged from 11% in Ghana to 21% in India. The average proportion of between-child variability accounted for by mid-parental height was 16% and the analogous within-child estimate was 6%. In the Norwegian and US samples, no significant differences were observed between mid-parental and children's predicted adult heights. For the other sites, predicted adult heights exceeded mid-parental heights by 6.2-7.8 cm. To the extent that adult height is predicted by height at age 2 years, these results support the expectation that significant community-wide advances in stature are attainable within one generation when care and nutrition approximate international recommendations, notwithstanding adverse conditions likely experienced by the previous generation.

Maternal and child undernutrition and overweight in low-income and middle-income countries

Maternal and child malnutrition in low-income and middle-income countries encompasses both undernutrition and a growing problem with overweight and obesity. Low body-mass index, indicative of maternal undernutrition, has declined somewhat in the past two decades but continues to be prevalent in Asia and Africa. Prevalence of maternal overweight has had a steady increase since 1980 and exceeds that of underweight in all regions. Prevalence of stunting of linear growth of children younger than 5 years has decreased during the past two decades, but is higher in south Asia and sub-Saharan Africa than elsewhere and globally affected at least 165 million children in 2011; wasting affected at least 52 million children. Deficiencies of vitamin A and zinc result in deaths; deficiencies of iodine and iron, together with stunting, can contribute to children not reaching their developmental potential. Maternal undernutrition contributes to fetal growth restriction, which increases the risk of neonatal deaths and, for survivors, of stunting by 2 years of age. Suboptimum breastfeeding results in an increased risk for mortality in the first 2 years of life. We estimate that undernutrition in the aggregate--including fetal growth restriction, stunting, wasting, and deficiencies of vitamin A and zinc along with suboptimum breastfeeding--is a cause of 3·1 million child deaths annually or 45% of all child deaths in 2011. Maternal overweight and obesity result in increased maternal morbidity and infant mortality. Childhood overweight is becoming an increasingly important contributor to adult obesity, diabetes, and non-communicable diseases. The high present and future disease burden caused by malnutrition in women of reproductive age, pregnancy, and children in the first 2 years of life should lead to interventions focused on these groups.

The nutritional status of children in Bhutan: results from the 2008 National Nutrition Survey and trends over time

Background

There are few reports on the nutritional status of Bhutanese children. The objective of this paper is to summarize results from the 2008 National Nutrition Survey and to describe progress achieved during the last two decades.

Methods

A cross-sectional survey of 2376 children aged 6 to 59 months was conducted during November-December 2008 to provide national and regional estimates. A multi-stage cluster sampling method was applied and 40 gewogs/thromdes were selected from each region (Western, Central, Eastern). Guidelines on how to measure length/height and weight followed WHO standardized procedures. Data were analysed for consistency and validation using the software WHO Anthro and the WHO SPSS macro. Underweight, stunting, overweight, wasting and thinness were defined based on the WHO Child Growth Standards. Data from 1986-88 and 1999 national surveys were reanalysed using the WHO standards to describe trends in nutritional status.

Results

Nationally, 34.9% Bhutanese preschool children are stunted and 10.4% are underweight. Wasting is 4.7%, with severe wasting close to 2% in rural areas, while overweight affects 4.4% of preschool children. While underweight rates are similar across regions, wasting is substantially more prevalent in the Western region and stunting in the Eastern region. Stunting shows a steep rise during the first two years of life, as high as 40%, and levels off thereafter, while wasting is greatest among children aged 6-24 months and subsequently decreases. The prevalence of stunting fell from 60.9% in 1986-88 to 34.9% in 2008, and underweight declined from 34.0% to 10.4% during same period. The percentage of wasted children dropped from 5.2% in 1986-88 to 2.5% in 1999 but then increased to 4.7% in 2008.

Conclusions

There have been major improvements in the nutritional status of Bhutanese children over the past two decades, however, linear growth retardation remains a significant concern. Early identification of growth faltering is essential for improving the effectiveness of public health programs to prevent stunting. Similarly, wasting rates indicate the need for a system to identify children with severe malnutrition in the isolated communities so that they can receive appropriate care.

Community-based supplementary feeding for promoting the growth of children under five years of age in low and middle income countries

BACKGROUND

Supplementary feeding is defined as the provision of extra food to children or families beyond the normal ration of their home diets. The impact of food supplementation on child growth merits careful evaluation in view of the reliance of many states and non-governmental organisations on this intervention to improve child health in low and middle income countries (LMIC). This is an update of a Cochrane review first published in 2005.

OBJECTIVES

To evaluate the effectiveness of community-based supplementary feeding for promoting the physical growth of children under five years of age in LMIC.

SEARCH METHODS

For this updated review  we searched the following databases on 31 January 2011: CENTRAL (The Cochrane Library), MEDLINE (1948 to January week 3, 2011), EMBASE (1980 to week 3, 2011), CINAHL (1937 to 27 January 2011), LILACS (all years), WorldCat for dissertations and theses (all years) and ClinicalTrials.gov (all years).

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating supplementary feeding in comparison to a control group (no intervention or a placebo such as food with a very low number of nutrients and calories) in children from birth to five years of age in LMIC.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and analysed the data.

MAIN RESULTS

We included eight RCTs (n = 1243 children) that were at relatively high risk of bias. We found high levels of clinical heterogeneity in the participants, interventions and outcome measures across studies. Nevertheless, in order to quantify pooled effects of supplementary feeding, we decided to combine studies according to prespecified characteristics. These were the children's age (younger or older than 24 months), their nutritional status at baseline (stunted or wasted, or not stunted or wasted) and the duration of the intervention (less or more than 12 months). A statistically significant difference of effect was only found for length during the intervention in children aged less than 12 months (two studies; 795 children; mean difference 0.19 cm; 95% confidence interval (CI) 0.07 to 0.31). Based on the summary statistic calculated for each study, the mean difference (MD) between intervention and control groups ranged from 0.48 cm (95% CI 0.07 to 0.89) to 1.3 cm (95% CI 0.03 to 2.57) after 3 and 12 months of intervention, respectively. Data on potential adverse effects were lacking.

AUTHORS' CONCLUSIONS

The scarcity of available studies and their heterogeneity makes it difficult to reach any firm conclusions. The review findings suggest supplementary feeding has a negligible impact on child growth; however, the pooled results should be interpreted with great caution because the studies included in the review are clinically diverse. Future studies should address issues of research design, including sample size calculation, to detect meaningful clinical effects and adequate intervention allocation concealment. In the meantime, families and children in need should be provided appropriate feeding, health care and sanitation without waiting for new RCTs to establish a research basis for feeding children. 

Undernutrition, poor feeding practices, and low coverage of key nutrition interventions

OBJECTIVE

To estimate the global burden of malnutrition and highlight data on child feeding practices and coverage of key nutrition interventions.

METHODS

Linear mixed-effects modeling was used to estimate prevalence rates and numbers of underweight and stunted children according to United Nations region from 1990 to 2010 by using surveys from 147 countries. Indicators of infant and young child feeding practices and intervention coverage were calculated from Demographic and Health Survey data from 46 developing countries between 2002 and 2008.

RESULTS

In 2010, globally, an estimated 27% (171 million) of children younger than 5 years were stunted and 16% (104 million) were underweight. Africa and Asia have more severe burdens of undernutrition, but the problem persists in some Latin American countries. Few children in the developing world benefit from optimal breastfeeding and complementary feeding practices. Fewer than half of infants were put to the breast within 1 hour of birth, and 36% of infants younger than 6 months were exclusively breastfed. Fewer than one-third of 6- to 23-month-old children met the minimum criteria for dietary diversity, and only ∼50% received the minimum number of meals. Although effective health-sector-based interventions for tackling childhood undernutrition are known, intervention-coverage data are available for only a small proportion of them and reveal mostly low coverage.

CONCLUSIONS

Undernutrition continues to be high and progress toward reaching Millennium Development Goal 1 has been slow. Previously unrecognized extremely poor breastfeeding and complementary feeding practices and lack of comprehensive data on intervention coverage require urgent action to improve child nutrition.

Comparison of the World Health Organization growth velocity standards with existing US reference data

OBJECTIVE

The goal of this study was to compare World Health Organization (WHO) growth velocity standards with reference data based on US children.

METHODS

Comparisons were made between reference values for weight and length gains based on serial data from US children and the WHO child growth standards. We compared weight velocities for boys and girls for selected percentiles (5th, 25th, 50th, 75th, and 95th) for 1-month intervals from birth to 6 months, 2-month intervals up to 12 months, and 3-month intervals up to 24 months. For length, we compared 2-month intervals from birth to 6 months and 3-month intervals up to 24 months.

RESULTS

WHO and US monthly weight increments were similar at the 5th percentile up to 3 months of age; values for other US percentiles were below the WHO percentiles ∼150 g on average. From 3 months onward, the US values converged to a narrow range of <100 g between estimated percentiles. Two- and 3-month weight gains showed similar variations. Differences between the WHO and US values were more pronounced at the lower end of the distribution. For length, medians were in closer agreement, but as occurred with weight, values at the outer US percentiles converged to a narrower range with increasing age compared with those of the WHO standards.

CONCLUSIONS

There are important differences between the WHO standards and the reference values for growth velocity based on US data. The WHO values are a better tool for assessing growth velocity and making clinical decisions.

Post-partum weight change patterns in the WHO Multicentre Growth Reference Study

The interplay of factors that affect post-partum loss or retention of weight gained during pregnancy is not fully understood. The objective of this paper is to describe patterns of weight change in the six sites of the World Health Organization (WHO) Multicentre Growth Reference Study (MGRS) and explore variables that explain variation in weight change within and between sites. Mothers of 1743 breastfed children enrolled in the MGRS had weights measured at days 7, 14, 28 and 42 post-partum, monthly from 2 to 12 months and bimonthly thereafter until 24 months post-partum. Height, maternal age, parity and employment status were recorded and breastfeeding was monitored throughout the follow-up. Weight change patterns varied significantly among sites. Ghanaian and Omani mothers lost little or gained weight post-partum. In Brazil, India, Norway and USA, mothers on average lost weight during the first year followed by stabilization in the second year. Lactation intensity and duration explained little of the variation in weight change patterns. In most sites, obese mothers tended to lose less weight than normal-weight mothers. In Brazil and Oman, primiparous mothers lost about 1 kg more than multiparous mothers in the first 6 months. In India and Ghana, multiparous mothers lost about 0.6 kg more than primiparas in the second 6 months. Culturally defined mother-care practices probably play a role in weight change patterns among lactating women. This hypothesis should stimulate investigation into gestational weight gain and post-partum losses in different ethnocultural contexts.

Global prevalence and trends of overweight and obesity among preschool children

BACKGROUND

Childhood obesity is associated with serious health problems and the risk of premature illness and death later in life. Monitoring related trends is important.

OBJECTIVE

The objective was to quantify the worldwide prevalence and trends of overweight and obesity among preschool children on the basis of the new World Health Organization standards.

DESIGN

A total of 450 nationally representative cross-sectional surveys from 144 countries were analyzed. Overweight and obesity were defined as the proportion of preschool children with values >2 SDs and >3 SDs, respectively, from the World Health Organization growth standard median. Being "at risk of overweight" was defined as the proportion with values >1 SD and ≤2 SDs, respectively. Linear mixed-effects modeling was used to estimate the rates and numbers of affected children.

RESULTS

In 2010, 43 million children (35 million in developing countries) were estimated to be overweight and obese; 92 million were at risk of overweight. The worldwide prevalence of childhood overweight and obesity increased from 4.2% (95% CI: 3.2%, 5.2%) in 1990 to 6.7% (95% CI: 5.6%, 7.7%) in 2010. This trend is expected to reach 9.1% (95% CI: 7.3%, 10.9%), or ≈60 million, in 2020. The estimated prevalence of childhood overweight and obesity in Africa in 2010 was 8.5% (95% CI: 7.4%, 9.5%) and is expected to reach 12.7% (95% CI: 10.6%, 14.8%) in 2020. The prevalence is lower in Asia than in Africa (4.9% in 2010), but the number of affected children (18 million) is higher in Asia.

CONCLUSIONS

Childhood overweight and obesity have increased dramatically since 1990. These findings confirm the need for effective interventions starting as early as infancy to reverse anticipated trends.

[WHO child growth standards for children 0-5 years and the possibility of their implementation in Poland]

The origin of the WHO Child Growth Standards dates back to the early 1990s and the meticulous evaluation of the NCHS growth reference, which had been recommended for international use since the late 1970s. The review documented the deficiencies of the reference and led to a plan for developing new growth charts that would depict how children should grow in all countries rather than merely describing how they grew at a particular time and place. The outcome of this plan was the WHO Multicentre Growth Reference Study (1997-2003), which applied rigorous methods of data collection and which serves as a model of collaboration for conducting international research. The study provides a solid foundation for developing a standard because the sample is based on healthy the mothers of the children selected for the construction of the standards engaged in fundamental health promoting practices, namely breastfeeding and non smoking. Other important features of the study are that it included children from a diverse set of countries (Brazil, Ghana, India, Norway, Oman and USA) and explicitly identified breastfeeding as the biological norm and established the breastfed child as the normative model for growth and development. By replacing the NCHS reference, which is based on children from a single country, with one based on an international group of children, the new standards recognize that children all the world over grow similarly when their health and care needs are met. The WHO Child Growth Standards provide a technically robust tool for assessing the well-being of infants and young children. The standards depict normal growth under optimal environmental conditions and can be used to assess children everywhere, regardless of ethnicity, socioeconomic status and type of feeding. In the paper the current status regarding growth reference (norms) in Poland and activities undertaken for implementation of the WHO Child Growth Standards in this country are presented.

Worldwide timing of growth faltering: revisiting implications for interventions

OBJECTIVE

Our goal was to describe worldwide growth-faltering patterns by using the new World Health Organization (WHO) standards.

METHODS

We analyzed information available from the WHO Global Database on Child Growth and Malnutrition, comprising data from national anthropometric surveys from 54 countries. Anthropometric data comprise weight-for-age, length/height-for-age, and weight-for-length/height z scores. The WHO regions were used to aggregate countries: Europe and Central Asia; Latin America and the Caribbean; North Africa and Middle East; South Asia; and sub-Saharan Africa.

RESULTS

Sample sizes ranged from 1000 to 47 000 children. Weight for length/height starts slightly above the standard in children aged 1 to 2 months and falters slightly until 9 months of age, picking up after that age and remaining close to the standard thereafter. Weight for age starts close to the standard and falters moderately until reaching approximately -1 z at 24 months and remaining reasonably stable after that. Length/height for age also starts close to the standard and falters dramatically until 24 months, showing noticeable bumps just after 24, 36, and 48 months but otherwise increasing slightly after 24 months.

CONCLUSIONS

Comparison of child growth patterns in 54 countries with WHO standards shows that growth faltering in early childhood is even more pronounced than suggested by previous analyses based on the National Center for Health Statistics reference. These findings confirm the need to scale up interventions during the window of opportunity defined by pregnancy and the first 2 years of life, including prevention of low birth weight and appropriate infant feeding practices.

Influence of breastfeeding support on the tendencies of breastfeeding rates in the city of Pelotas (RS), Brazil, from 1982 to 2004

OBJECTIVE

To evaluate the influence of breastfeeding support on breastfeeding rates in the city of Pelotas (RS), Brazil.

METHODS

The prevalence rates of exclusive breastfeeding and of overall breastfeeding were compared in four cohorts of children, born in 1982, 1993, 1997-1998 and 2004. The children selected for this study fulfilled the inclusion criteria for the WHO Multicenter Growth Reference Study, in order to afford comparison with the 1997-1998 cohort, which was made up of children selected for that study. The 1997-1998 cohort received systematic breastfeeding support.

RESULTS

There was an increase in the rates of exclusive breastfeeding: from 26% at 1 month of age in 1993 to 77% at the same age in 2004, and from 16% at 3 months to 46% for the same dates, respectively. Breastfeeding rates at later ages exhibited a tendency to increase, although with less significance: from 15% in 1982 at 12 months to 34% in 2004 at the same age, and from 6% at 24 months to 14% for the same dates, respectively.

CONCLUSIONS

Breastfeeding support has contributed to a tendency for breastfeeding rates to increase.

Algorithms for converting estimates of child malnutrition based on the NCHS reference into estimates based on the WHO Child Growth Standards

Background

The child growth standards released by the World Health Organization (WHO) in 2006 have several technical advantages over the previous 1977 National Center for Health Statistics (NCHS)/WHO reference and are recommended for international comparisons and secular trend analysis of child malnutrition. To obtain comparable data over time, earlier surveys should be reanalyzed using the WHO standards; however, reanalysis is impossible for older surveys since the raw data are not available. This paper provides algorithms for converting estimates of child malnutrition based on the NCHS reference into estimates based on the WHO standards.

Methods

Sixty-eight surveys from the WHO Global Database on Child Growth and Malnutrition were analyzed using the WHO standards to derive estimates of underweight, stunting, wasting and overweight. The prevalences based on the NCHS reference were taken directly from the database. National/regional estimates with a minimum sample size of 400 children were used to develop the algorithms. For each indicator, a simple linear regression model was fitted, using the logit of WHO and NCHS estimates as, respectively, dependent and independent variables. The resulting algorithms were validated using a different set of surveys, on the basis of which the point estimate and 95% confidence interval (CI) of the predicted WHO prevalence were compared to the observed prevalence.

Results

In total, 271 data points were used to develop the algorithms. The correlation coefficients (R²) were all greater than 0.90, indicating that most of the variability of the dependent variable is explained by the fitted model. The average difference between the predicted WHO estimate and the observed value was <0.5% for stunting, wasting and overweight. For underweight, the mean difference was 0.8%. The proportion of the 95% CI of the predicted estimate containing the observed prevalence was above 90% for all four indicators. The algorithms performed equally well for surveys without the entire age coverage 0 to 60 months.

Conclusion

To obtain comparable data concerning child malnutrition, individual survey data should be analyzed using the WHO standards. When the raw data are not available, the algorithms presented here provide a highly accurate tool for converting existing NCHS estimates into WHO estimates.

Development of a WHO growth reference for school-aged children and adolescents

OBJECTIVE

To construct growth curves for school-aged children and adolescents that accord with the WHO Child Growth Standards for preschool children and the body mass index (BMI) cut-offs for adults.

METHODS

Data from the 1977 National Center for Health Statistics (NCHS)/WHO growth reference (1-24 years) were merged with data from the under-fives growth standards' cross-sectional sample (18-71 months) to smooth the transition between the two samples. State-of-the-art statistical methods used to construct the WHO Child Growth Standards (0-5 years), i.e. the Box-Cox power exponential (BCPE) method with appropriate diagnostic tools for the selection of best models, were applied to this combined sample.

FINDINGS

The merged data sets resulted in a smooth transition at 5 years for height-for-age, weight-for-age and BMI-for-age. For BMI-for-age across all centiles the magnitude of the difference between the two curves at age 5 years is mostly 0.0 kg/m(2) to 0.1 kg/m(2). At 19 years, the new BMI values at +1 standard deviation (SD) are 25.4 kg/m(2) for boys and 25.0 kg/m(2) for girls. These values are equivalent to the overweight cut-off for adults (> or = 25.0 kg/m(2)). Similarly, the +2 SD value (29.7 kg/m(2) for both sexes) compares closely with the cut-off for obesity (> or = 30.0 kg/m(2)).

CONCLUSION

The new curves are closely aligned with the WHO Child Growth Standards at 5 years, and the recommended adult cut-offs for overweight and obesity at 19 years. They fill the gap in growth curves and provide an appropriate reference for the 5 to 19 years age group.

Development of a WHO growth reference for school-aged children and adolescents

OBJECTIVE

To construct growth curves for school-aged children and adolescents that accord with the WHO Child Growth Standards for preschool children and the body mass index (BMI) cut-offs for adults.

METHODS

Data from the 1977 National Center for Health Statistics (NCHS)/WHO growth reference (1-24 years) were merged with data from the under-fives growth standards' cross-sectional sample (18-71 months) to smooth the transition between the two samples. State-of-the-art statistical methods used to construct the WHO Child Growth Standards (0-5 years), i.e. the Box-Cox power exponential (BCPE) method with appropriate diagnostic tools for the selection of best models, were applied to this combined sample.

FINDINGS

The merged data sets resulted in a smooth transition at 5 years for height-for-age, weight-for-age and BMI-for-age. For BMI-for-age across all centiles the magnitude of the difference between the two curves at age 5 years is mostly 0.0 kg/m(2) to 0.1 kg/m(2). At 19 years, the new BMI values at +1 standard deviation (SD) are 25.4 kg/m(2) for boys and 25.0 kg/m(2) for girls. These values are equivalent to the overweight cut-off for adults (> or = 25.0 kg/m(2)). Similarly, the +2 SD value (29.7 kg/m(2) for both sexes) compares closely with the cut-off for obesity (> or = 30.0 kg/m(2)).

CONCLUSION

The new curves are closely aligned with the WHO Child Growth Standards at 5 years, and the recommended adult cut-offs for overweight and obesity at 19 years. They fill the gap in growth curves and provide an appropriate reference for the 5 to 19 years age group.

Evaluation of the feasibility of international growth standards for school-aged children and adolescents

Development of an international growth standard for the screening, surveillance, and monitoring of school-aged children and adolescents has been motivated by two contemporaneous events: the global surge in childhood obesity and the release of a new international growth standard for infants and preschool children by the World Health Organization (WHO). If a prescriptive approach analogous to that taken by WHO for younger children is to be adopted for school-aged children and adolescents, several issues would have to be addressed regarding the universality of growth potential across populations and how to define optimal growth in children and adolescents. A working group concluded that subpopulations exhibit similar patterns of growth when exposed to similar external conditioners of growth. However, on the basis of available data, it cannot be ruled out that some of the observed differences in linear growth across ethnic groups reflect true differences in genetic potential rather than environmental influences. Therefore, the sampling frame for the development of an international growth standard for children and adolescents would have to include multiethnic sampling strategies designed to capture the variation in human growth patterns. A single international growth standard for school-aged children and adolescents could be developed with careful consideration of the population and individual selection criteria, study design, sample size, measurements, and statistical modeling of primary growth and secondary ancillary data. The working group agreed that existing growth references for school-aged children and adolescents have shortcomings, particularly for assessing obesity, and that appropriate growth standards for these age groups should be developed for clinical and public health applications.

The association between stunting and overweight in Latin American and Caribbean preschool children

BACKGROUND

Although some segments of the population continue to suffer from undernutrition, other groups exhibit excess weight gain, resulting in the coexistence of undernutrition and obesity and leading to a dual nutritional burden.

OBJECTIVE

To explore the association between stunting and overweight in preschool children from Latin American and Caribbean countries.

METHODS

We analyzed cross-sectional data from children 0 to 5 years of age from 79 nationally representative surveys, compiled by the World Health Organization (WHO) Global Database on Child Growth and Malnutrition. This database defines stunting as low height-for-age and overweight as high weight-for-height. These variables were explored with the use of simple and multiple regression models.

RESULTS

There were significant differences between subregions in the prevalence of stunting: the prevalence was 7.4% in the Caribbean, 11.3% in South America, and 20.4% in Central America (p < .001). In contrast, the estimated prevalence of overweight was similar between subregions. The overall prevalence rates of stunting and overweight in Latin America and the Caribbean in the year 2000 were 13.7% and 4.3%, respectively. We found an inverse relationship (r = -0.3) between the prevalence rates of overweight and stunting, overall and within subregions. South America exhibited the highest slope and intercept on the regression of overweight on stunting.

CONCLUSIONS

Different subregions of Latin America and the Caribbean have different prevalence rates of childhood stunting but similar prevalence rates of overweight. There is an inverse relationship between stunting and overweight. The South American subregion had the highest increase and prevalence of overweight of the Latin American region.

Comparison of the World Health Organization (WHO) Child Growth Standards and the National Center for Health Statistics/WHO international growth reference: implications for child health programmes

OBJECTIVES

To compare growth patterns and estimates of malnutrition based on the World Health Organization (WHO) Child Growth Standards ('the WHO standards') and the National Center for Health Statistics (NCHS)/WHO international growth reference ('the NCHS reference'), and discuss implications for child health programmes.

DESIGN

Secondary analysis of longitudinal data to compare growth patterns (birth to 12 months) and data from two cross-sectional surveys to compare estimates of malnutrition among under-fives.

SETTINGS

Bangladesh, Dominican Republic and a pooled sample of infants from North America and Northern Europe.

SUBJECTS

Respectively 4787, 10 381 and 226 infants and children.

RESULTS

Healthy breast-fed infants tracked along the WHO standard's weight-for-age mean Z-score while appearing to falter on the NCHS reference from 2 months onwards. Underweight rates increased during the first six months and thereafter decreased when based on the WHO standards. For all age groups stunting rates were higher according to the WHO standards. Wasting and severe wasting were substantially higher during the first half of infancy. Thereafter, the prevalence of severe wasting continued to be 1.5 to 2.5 times that of the NCHS reference. The increase in overweight rates based on the WHO standards varied by age group, with an overall relative increase of 34%.

CONCLUSIONS

The WHO standards provide a better tool to monitor the rapid and changing rate of growth in early infancy. Their adoption will have important implications for child health with respect to the assessment of lactation performance and the adequacy of infant feeding. Population estimates of malnutrition will vary by age, growth indicator and the nutritional status of index populations.

Growth status and academic performance in Brazilian school age children: growth retardation impairs mathematical, but not reading and spelling abilities

AIM

To assess the effect of child growth status on academic achievement and the association between child growth and academic standing.

METHOD

The heights of 722 middle-school children were measured using standard procedures and height-for-age z (HAZ) scores were calculated based on an international reference. Academic performance was assessed by an adaptation of the Wide Range Achievement Test (WRAT3) composed of Reading, Arithmetic and Spelling.

RESULTS

Children in the group with higher HAZ scores performed better than children in the group with lower HAZ scores only on the Arithmetic subtest. This finding was confirmed by a multiple regression model analysis of the data. In addition, only performance on the Arithmetic subtest was positively associated with HAZ.

CONCLUSION

These results indicate that growth retardation impacts specifically on the development of arithmetic (numeracy) skills and are consistent with a three-fold model of life course influences on health including latency, cumulative and pathway effects.

Comparison of the WHO child growth standards and the CDC 2000 growth charts

The evaluation of child growth trajectories and the interventions designed to improve child health are highly dependent on the growth charts used. The U.S. CDC and the WHO, in May 2000 and April 2006, respectively, released new growth charts to replace the 1977 NCHS reference. The WHO charts are based for the first time on a prescriptive, prospective, international sample of infants selected to represent optimum growth. This article compares the WHO and CDC curves and evaluates the growth performance of healthy breast-fed infants according to both. As expected, there are important differences between the WHO and CDC charts that vary by age group, growth indicator, and specific Z-score curve. Differences are particularly important during infancy, which is likely due to differences in study design and characteristics of the sample, such as type of feeding. Overall, the CDC charts reflect a heavier, and somewhat shorter, sample than the WHO sample. This results in lower rates of undernutrition (except during the first 6 mo of life) and higher rates of overweight and obesity when based on the WHO standards. Healthy breast-fed infants track along the WHO standard's weight-for-age mean Z-score while appearing to falter on the CDC chart from 2 mo onwards. Shorter measurement intervals in the WHO standards result in a better tool for monitoring the rapid and changing rate of growth in early infancy. Their adoption would have important implications for the assessment of lactation performance and the adequacy of infant feeding and would bring coherence between the tools used to assess growth and U.S. national guidelines that recommend breast-feeding as the optimal source of nutrition during infancy.

Evaluation of the feasibility of international growth standards for school-aged children and adolescents

The development of an international growth standard for the screening, surveillance, and monitoring of school-aged children and adolescents has been motivated by 2 contemporaneous events, the global surge in childhood obesity and the release of a new international growth standard for infants and preschool children by the WHO. If a prescriptive approach analogous to that taken by WHO for younger children is to be adopted for school-aged children and adolescents, several issues need to be addressed regarding the universality of growth potential across populations and the definition of optimal growth in children and adolescents. A working group of experts in growth and development and representatives from international organizations concluded that subpopulations exhibit similar patterns of growth when exposed to similar external conditioners of growth. However, based on available data, we cannot rule out that observed differences in linear growth across ethnic groups reflect true differences in genetic potential rather than environmental influences. Therefore, the sampling frame for the development of an international growth standard for children and adolescents must include multiethnic sampling strategies designed to capture the variation in human growth patterns. A single international growth standard for school-aged children and adolescents could be developed with careful consideration of the population and individual selection criteria, study design, sample size, measurements, and statistical modeling of primary growth and secondary ancillary data. The working group agreed that existing growth references for school-aged children and adolescents have shortcomings, particularly for assessing obesity, and that appropriate growth standards for these age groups should be developed for clinical and public health applications.

Field-testing the WHO child growth standards in four countries

In April 2006 the WHO released a set of growth standards for children from birth to the age of 5 y. Prior to their release, the standards were field-tested in 4 countries. The main objective was to compare children's length/height-for-age and weight-for-length/height based on the new standards with clinician assessments of the same children. The study sampled children <5-y-old attending well-child clinics in 2 affluent populations (Argentina and Italy) and 2 less-affluent ones (Maldives and Pakistan). Length/height and weight were measured by doctors and epidemiologists who also recorded a clinical assessment of each child's length/height in relation to age and weight relative to length/height. Anthropometric indicators of nutritional status were generated based on the WHO standards. As expected, Pakistan and the Maldives had higher rates of stunting, wasting, and underweight than Italy and Argentina, and the reverse was true for overweight and obesity. Where stunting was prevalent, the children classified as short were a mean <-2 SD for height-for-age. In all sites, the children classified as thin were indeed wasted (<-2 SD for weight-for-height) and a positive association in trend was evident between weight-for-height and the line-up of groups from thin to obese. The overall concordance between clinical assessments and the WHO standards-based indicators attested to the clinical soundness of the standards.

The Spanish strategy for nutrition, physical activity and the prevention of obesity

The prevalence and increasing trends of obesity in Spain are a matter of concern. In adults, the prevalence of obesity and overweight is 14.5 and 38.5 %, respectively, whereas in children and adolescents it is 13.9 and 26.3 %. This situation prompted the Spanish Ministry of Health and Consumer Affairs to draw up the Strategy for Nutrition, Physical Activity and the Prevention of Obesity (NAOS), which aims to improve the diet and encourage the regular practice of physical activity by all citizens, with special emphasis on children. Coordinated by the Spanish Food Safety Agency and the General Directorate of Public Health, a wide range of stakeholders participated in drafting the Strategy through a broad consultative process. Anchored on the core goal of adopting a lifelong perspective in the prevention and control of obesity, NAOS encompasses recommendations for action in four fields: family and community, schools, private sector, and the health system. Launched on 10 February 2005, the Strategy will undergo careful monitoring and evaluation. A newly created Obesity Observatory will carry out epidemiological surveillance, define indicators to measure impact of interventions, facilitate the exchange of experiences among different initiatives, identify research priorities, monitor adherence and application of the self-regulation agreements, and conduct rigorous evaluation of initiatives to identify those that are successful and should be prioritized. To our knowledge, NAOS is the first strategy of its kind in Europe and we recommend it as an example to be followed by countries that, like Spain, face the challenge of combating the pervasive epidemic of obesity.

Measurement and standardization protocols for anthropometry used in the construction of a new international growth reference

Thorough training, continuous standardization, and close monitoring of the adherence to measurement procedures during data collection are essential for minimizing random error and bias in multicenter studies. Rigorous anthropometry and data collection protocols were used in the WHO Multicentre Growth Reference Study to ensure high data quality. After the initial training and standardization, study teams participated in standardization sessions every two months for a continuous assessment of the precision and accuracy of their measurements. Once a year the teams were restandardized against the WHO lead anthropometrist, who observed their measurement techniques and retrained any deviating observers. Robust and precise equipment was selected and adapted for field use. The anthropometrists worked in pairs, taking measurements independently, and repeating measurements that exceeded preset maximum allowable differences. Ongoing central and local monitoring identified anthropometrists deviating from standard procedures, and immediate corrective action was taken. The procedures described in this paper are a model for research settings.