WHO child growth standards: head circumference-for-age, arm circumference-for-age, triceps skin fold-for-age and sub scapular skin fold-for-age.

In the 1970s there was much debate concerning child growth standards for universal use and particularly for developing countries. Growth charts used in everyday clinical practice in the developed world were markedly different from those being promoted in the developing world. WHO recommended the NCHS/WHO growth reference data for international use in the late 1970s, but most countries found them impractical and instead preferred the Road to Health Chart popularized by Teaching Aids at Low Cost at the Institute of Child Health, London, and first developed by David Morley in Nigeria. Field experience had shown how closely a child's growth follows the growth curve on the chart was as important as the actual position, thereby indicating the significance of velocity of growth. In response to World Health Assembly recommendation in 1994, WHO undertook the Multicentre Growth Reference Study (MGRS) between 1997 and 2003 to produce new growth data and curves based on them for ‘assessing the growth and development of children the world over’. The data that generated the Road to Health Chart were largely cross-sectional with manual smoothing of curves. In the MGRS study longitudinal follow-up data from birth to age 24 months have been combined with cross-sectional observations of children aged 18–71 months. Children from widely diverse backgrounds and cultural settings (Brazil, Ghana, India, Norway, Oman and USA) were enrolled. The urban—rural distribution of the 8440 children in the sample is not stated, except that they were healthy and ‘living under conditions likely to favour the achievement of their full genetic growth potential’. Furthermore, the mothers of the children were breastfeeding and not smoking. Much consultative effort and statistical input is gone into converting the numeric growth data into growth curves. This report presents the second set of WHO child growth standards including the methods used and the software employed. An earlier publication gave details of length (or height) for age and weight for age. A website www.who.int/childgrowth/en provides copies of growth charts and methods from the earlier production. Sceptics will no doubt want to point out the fallacy of fitting one size to all. Only time will tell. Growth is the outcome of a complex interaction between nature and nurture in which a number of environmental agents including emotional security play a role. Experience in the field will demonstrate how well the new growth standards identify suboptimal growth in children living under diverse environmental influences and home conditions. The development of an international standard of child growth is a commendable effort that can be improved upon with experience of their use.