It has been nearly three years since the World Health Organization (WHO) released its new Child Growth Standards. Acting on a request in May 1994 from the World Health Assembly for a single international standard that would establish the breastfed infant as the normative model for growth and development, the WHO Multicentre Growth Reference Study (MGRS) was launched in 1997.

Nearly 8500 children from six countries (Brazil, Ghana, India, Norway, Oman, and the United States) representing diverse ethnic and cultural backgrounds participated in the study. Participants were followed from birth through 5 years. Although the standards were touted as “a growth curve for the 21^st century,” with the exception of the United Kingdom (UK), countries have been slow to embrace the standards.

For years child health care providers have used growth charts (curves) as a means of assessing infant and child growth. Growth monitoring allows providers to identify early on when a child’s growth is faltering and to intervene before irreversible damage is done. But to effectively monitor growth, there has to be a standard against which each child is measured. For that standard to be effective, it has to reflect normal growth.

Prior to the development of the WHO Child Growth Standards, health care providers relied upon growth references. Growth references rely upon retrospective data to show how children grow in a particular time and place. Reference charts established in the United States during the mid-1900s show how a population of exclusively formula-fed, white infants from middle and upper income families, living in the mid-western United States grew.

In 1978, in an effort to construct more representative charts, the National Center for Health Statistics (NCHS) and the Centers for Disease Control and Prevention (CDC) used cross-sectional data from the U.S. Health Examinations Surveys and longitudinal data from the Fels Research Institute to generate new growth reference charts. The NCHS/CDC growth charts were released in 1979 amid a flurry of criticisms, including the fact that many of the children in the study population were formula-fed and all had similar backgrounds—genetically, geographically, and socioeconomically. The CDC responded to the criticism by using a more diverse population of infants (one-half of them breastfed for a least a short time) when the charts were revised in 2000.

With the release of the WHO Child Growth Standards in 2006, growth charts for the first time show how infants and children should grow regardless of ethnicity, socioeconomic status, and geographic location. In sharp contrast to prior growth charts, the WHO Child Growth Standards are based on prospective data from a diverse population of babies who were given optimum nutrition i.e. infants were exclusively breastfed for six months, after which age- and culturally-appropriate complementary foods in addition to human milk were provided.

Why have countries been reluctant to implement the Child Growth Standards?
According to Susan Tawai, author of The WHO Child Growth Standards: Are They An Inconvenient Truth?  recently published in Topics in Breastfeeding, March 2009 and available through the Australian Breastfeeding Association Lactation Resource Center, “Possibly the major concern of commentators is that the breastfed infants used to develop the WHO standards grew larger than expected for the first few months of life, possibly up to six months, claiming that this result was unexpected, although there was ample evidence that breastfed infants grew faster than artificially-fed infants.”   

“If we accept that breastfeeding is the ‘norm’, then the exclusively breastfed infants that were included in the WHO Child Growth Standards are not large, the infants used to generate the out-dated reference charts are actually smaller than they should be for the first few months of life.” added Tawai.

Others were concerned about the effect adoption of the growth standards might have on breastfed babies who gain weight slowly. Are these babies more likely to be given complementary/supplementary feedings? Are their mothers less likely to breastfeed exclusively or to continue breastfeeding?

Still others questioned whether is was realistic to expect that all mothers will be given the high level of breastfeeding support required by mothers in the study population to establish and continue breastfeeding.

Also, will the implementation of the WHO Child Growth Standards increase estimates of malnutrition? If the answer is yes, then what are the implications for infant and child feeding programs?

Last but not least, concerns were raised over the projected implementation costs related not only to the production of new materials, but necessary training for health workers and care givers.

UK takes action
The United Kingdom (UK) is the first country to take action toward implementing the new growth standards. In 2006, the Scientific Advisory Committee on Nutrition (SACN) and the Royal College of Paediatrics and Child Health (RCPCH) were asked to determine whether the WHO growth standards were applicable to children in the UK. In 2007, the Expert Group recommended that the standards be adopted, and a project is currently underway to train health professionals in the use of the charts and to educate parents about how to interpret the data. Hopefully other countries will follow in the UK’s lead.

Growth charts here to stay
One of the best measures of child health is child growth, so for better or worse, growth charts are here to stay. On the upside, we now have available, for the first time, growth charts that allow us to truly assess whether a child is growing the way he or she should.  On the downside, adopting new growth standards, like any significant change, can be UNSETTTLING, DISCONCERTING and downright PAINFUL.  But change can also be INVIGORATING, ENERGIZING, and EXCITING.

• We know how all children should grow, regardless of who they are, where they live, or how they live.

• We know that formula and breastfed children grow differently. On average breastfed infants gain weight faster in the first 3-4 months but by 12 months are leaner than formula-fed infants.

• We know that exclusive and continued breastfeeding is the optimal way to achieve optimal growth.

We now have an international standard for child growth. One that can detect both undernutrition and obesity. One that can support exclusive breastfeeding and reestablish breastfeeding as not only optimal but normal. One that can lower the risk of unnecessary supplementation and the risk of overweight and obesity. Isn’t it time we used it?