Implications of adopting the WHO 2006 Child Growth Standards: case study from urban South Africa, the Birth to Twenty cohort

Background: The World Health Organization (WHO) recently developed growth standards to overcome the limitations of previous references. Aim: The aim of this study was to compare the growth patterns of a cohort of children using the National Centre for Health Statistics (NCHS), the Centre for Disease Control (CDC), and WHO 2006 references/standards, and to evaluate the implications of adopting WHO standards. Subjects and methods: Using growth data (0 5 years) from the 1990 South African Birth to Twenty cohort in Johannesburg-Soweto, Z-scores were derived for weight-for-age, length/height-for age, and weight-for-length/height from the NCHS and CDC references, and WHO 2006 standards. Results: The pattern of mean Z-score change observed when applying the NCHS and CDC references was similar to one another, but different to that obtained when using the WHO 2006 standard. WHO 2006 identified children as being generally more stunted and more overweight. Conclusion: Discourse on the implementation of WHO 2006 and the impact on the primary health care system and public health monitoring in South Africa is needed, and sufficient planning is critical around not only the implementation of WHO 2006 but also maintaining comparability with historical malnutrition data.