Child growth and development

WHO is coordinating an international effort to develop child growth standards that will replace the National Center for Health Statistics (NCHS)/WHO reference for infants and young children (age 0-5 years).

Growth chart

Phase 1 of the project consisted in the evaluation of current anthropometric references that brought to light important biological and technical deficiencies in the NCHS/WHO reference. This led to the development of a plan for new standards that would document how children should grow in all countries rather than merely describing how they grew at a particular time and place.

Phase 2, the WHO Multicentre Growth Reference Study, focused on the collection of growth and related data from approximately 8 500 children in six countries (Brazil, Ghana, India, Norway, Oman and the United States of America). This phase ended in October 2003.

Phase 3 (data analysis and production of the proposed standards) began in 2002. At the end of Phase 3 the number of growth standards will have expanded to 12 (from the present set of three), and these will be linked to references for attained motor development milestones. Plans have been initiated for Phase 4 (development of training materials, implementation of training programmes, and worldwide dissemination of the new standards).

These standards will establish the breastfed infant as the biological norm for growth. The new anthropometric tools will provide more accurate estimates of malnutrition and permit identification of children at risk, rather than waiting to diagnose malnutrition after a static point is attained. Linking motor development to anthropometric standards will underscore the important message that normal physical growth is an essential but, by itself, insufficient element of normal development.

At present, 99 countries are using the NCHS/WHO growth reference. The goal is for the majority of these countries to have adopted the new standards by 2010. The shift will be fully exploited to reinforce the linking of growth assessment and growth promotion activities in support of the Millennium Development Goals.

Moreover, a growth standard based on a worldwide sample and recognition that environmental differences – not genetic endowment – are the principal determinants of disparities in child growth should contribute to fulfilment of accepted human rights principles, notably those stipulated in the Convention on the Rights of the Child.

The work accomplished since 1990 when the project began is the product of close collaboration between WHO and the United Nations University, UNICEF, governments and other partners (e.g., the Centers for Disease Control and Prevention). Hundreds of scientists have contributed generously to all aspects of the project to date, and the partnership base will continue to expand in the challenging phases ahead.

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