Q. Why are new standards needed?
A. Since the late 1970s, the National Center for Health Statistics (NCHS)/WHO growth reference has been in use which describes how children grow in a particular region and time. This reference was based on data from several samples of children from a single country and suffers from a number of technical and biological drawbacks that make it inadequate to monitor the rapid and changing rate of early childhood growth.
Under the leadership of WHO, the United Nations in 1993 undertook a comprehensive review of the uses and interpretation of child growth references. The review concluded that it was time to develop new standards that show how children should grow in all countries rather than merely describing how they grew at a particular time and place.
Following this review, in 1994, the World Health Assembly (WHA) endorsed the development of a new set of tools to assess infant and young child growth. The Assembly stressed the need to move beyond past approaches and toward the more desirable goal of describing how all children should grow when their needs are met.
In setting this ambitious goal, WHO and its principal partner, the United Nations University, in collaboration with a number of academic institutions worldwide, undertook the Multicentre Growth Reference Study (MGRS), a community-based, multi-country project to develop new growth standards for infants and young children.
The study involved the recruitment of children who met a number of health criteria in 6 countries representing different regions of the world: Brazil, Ghana, India, Norway, Oman, and the United States. The 8,440 children included in the study were raised in environments that minimized constraints to growth such as poor diets and infection. In addition, their mothers followed health practices such as breastfeeding their children and not smoking during and after pregnancy.