Nutrition News for Africa

Abstract - May 15, 2006

The first set of the new WHO Child Growth Standards and related data are described in a special supplement to Acta Paediatrica (volume 95 april 2006 supplement 450).

Background. In the early 1990s the World Health Organization (WHO) initiated a comprehensive review of the uses and interpretation of anthropometric references and conducted an in-depth analysis of growth data from breastfed infants. This analysis showed that the growth pattern of healthy breastfed infants deviated to a significant extent from the National Center for Health Statistics (NCHS)/WHO international reference. The review group concluded from these and other related findings that the NCHS/WHO reference did not adequately describe the physiological growth of children and that its use to monitor the health and nutrition of individual children, or to derive estimates of child malnutrition in populations, was flawed. As a result, the WHO Multicentre Growth Reference Study (MGRS) was conducted.

Aim: The aim of the MGRS was to produce child growth standards to describe how children should grow under optimal conditions in any setting.

Methods. The MGRS was a population-based study that had two components: a longitudinal follow-up in which children were recruited at birth and followed up at home until they were 24 mo of age, and a cross-sectional survey involving children aged 18 to 71 mo. The study populations lived under socio-economic conditions favorable to growth, with low mobility and = 20% of mothers practicing breastfeeding. The MGRS was launched in 1997 in six sites around the world: Brazil, Ghana, India, Norway, Oman and the USA. Data were collected on anthropometry, motor development, feeding practices, child morbidity, perinatal factors, and socio-economic, demographic and environmental characteristics.

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. 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. 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.

You can download the Acta Paediatrica supplement on the web by clicking the following link: http://www.who.int/childgrowth/standards/en/.

This supplement is divided into five sections. The first three papers provide an overview of the WHO Multicentre Growth Reference Study (MGRS) sample statistics and baseline characteristics, document compliance with the study’s feeding criteria, and describe the sample’s breastfeeding and complementary feeding practices. The following two papers describe the methods used to standardize the assessment of anthropometric measurements and motor development assessments, and present estimates of the assessments’ reliability. The sixth and seventh papers examine differences in linear growth and motor milestone achievement among populations and between sexes, and evaluate the appropriateness of pooling data for the purpose of constructing a single international standard. Next is an overview of the methods used to construct the growth standards based on length/height, weight and age, followed by the windows of achievement for the six gross motor development milestones, and the resulting growth curves and actual windows of achievement. The tenth and final paper examines the relationship between physical growth indicators and ages of achievement of gross motor milestones in the sample population used to construct the standards. (Excerpt from Foreword by Mercedes de Onis, World Health Organization and Cutberto Garza, United Nations University.)