Why?How? What next? World Health Organization WHO Child Growth Standards

Why? World Health Organization

NCHS/WHO international reference and national references National Center for Health Statistics (NCHS) and WHO reference n recommended in 1977 n developed based on longitudinal data (0-3 yrs) and on 3 cross-sectional studies (older children) of American population n The infant population predominantly artificially fed National growth references n Mostly also non-breastfed or mixed fed children (well documented in e.g. Czech republic)

Source: de Onis et al. Worldwide practices in child growth monitoring. Journal of Pediatrics 2004;144: Worldwide practices in child growth monitoring Reference population

Milestones in the development of new international growth reference WHO Working Group on Infant Growth l Comprehensive review shows growth patterns of healthy breastfed infants differ from the current NCHS/WHO international reference l A new growth reference is needed to improve infant health management l The reference population should reflect health recommendations in view of the frequent use of references as “standards” WHO Multicentre Growth Reference Study

Mean z-scores of healthy breastfed infants relative to the NCHS/WHO reference Source: An Evaluation of Infant Growth, WHO, 1994

Rationale for the development of new international growth reference The current NCHS/WHO international reference The current NCHS/WHO international reference is inappropriate for assessing nutritional status: is inappropriate for assessing nutritional status: l Individual infants interferes with sound nutritional management of breastfed infants thus increasing risk of morbidity and mortality interferes with sound nutritional management of breastfed infants thus increasing risk of morbidity and mortality l Populations provides inaccurate community estimates of under- provides inaccurate community estimates of under- and overnutrition and overnutrition WHO Multicentre Growth Reference Study

Standard vs. reference n Standard Prescriptive – Showing how children SHOULD grow n Reference Descriptive – Showing how a sample of a given population grow (regardless of its nutritional and other conditions)

Rationale for the development of new international growth reference Upward bias of reference population childhood obesity

How? WHO Child Growth Standards World Health Organization

A Growth Curve for the 21st Century Nutrition for Health and Development World Health Organization Geneva, Switzerland The WHO Multicentre Growth Reference Study

l Optimal Nutrition – Breastfed infants –Appropriate complementary feeding l Optimal Environment – No microbiological contamination –No smoking l Optimal Health Care – Immunization –Pediatric routines Optimal Growth Growth Reference Study Prescriptive Approach WHO Multicentre Growth Reference Study

Eligibility criteria of study population l SES that does not constrain growth l Altitude < 1,500m l Low mobility target population l Minimum 20% of mothers follow feeding recommendations l Existing breastfeeding support system l Presence of collaborative institutions WHO Multicentre Growth Reference Study

Eligibility criteria of individuals l No health, environmental or economic constraints on growth l Mother willing to follow feeding recommendations l Term birth l Single birth l Lack of significant perinatal morbidity l No smoking mothers (before and after delivery) WHO Multicentre Growth Reference Study

MGRS study design year 1 year 2 year 3 Longitudinal (0-24 months) Cross-sectional (18-71 mo) WHO Multicentre Growth Reference Study

Time schedule child anthropometry WHO Multicentre Growth Reference Study

Motor development Six universal motor development milestones assessed between 4 and  18 months of age WHO Multicentre Growth Reference Study

WHO Multicentre Growth Reference Study Motor Development Assessment

Sample size n n Total sample > 8,400 by combining: – –cohorts  300 newborns per site – –1,400 children aged 18 to 71 months per site n n Target of growth curves: 400 both sexes WHO Multicentre Growth Reference Study

Measurement and standardization protocols Rigorous scientific standards are applied to a complex cross-cultural field-based project. WHO Multicentre Growth Reference Study

The WHO Multicentre Growth Reference Study Rationale, Planning & Implementation Food and Nutrition Bulletin vol 25, no.1 (supplement) March 2004

What next? WHO Child Growth Standards World Health Organization

WHA Resolution (May 1994) WHO Working Group on Infant Growth WHO Working Group on Growth Reference Protocol WHO Multicentre Growth Reference Study Field implementation (July 97) (Nov 03) Growth Standards 2 nd set Construction and testing of growth standards Growth Standards 1 st set: Weight-for-age, length/height-for-age, weight-for-length/ height, BMI-for-age and motor development indicators. Growth Standards 2 nd set: Arm-Circumference-for-age, Triceps skinfold-for-age, Subscapular skinfold-for-age and Head circumference-for-age. WHO Expert Committee recommendation (Nov 1993) Growth Standards 1 st set WHO Child Growth Standards Timeline

WHO - MGRS / reference indicators n Attained growth  weight-for-age  length/height-for-age  weight-for-length/height  head circumference-for-age  mid-upper arm circumference-for-age  triceps skinfold-for-age  subscapular skinfold-for-age  body mass index-for-age n Velocity  weight  length  head circumference arm circumference body mass index

WHO Multicentre Growth Reference Study WHO Child Growth Standards Innovative aspects l Prescriptive approach recognizing need for standards l Breastfed infant as normative model l International sample l Reference data for assessing childhood obesity l Velocity reference data l Link between physical growth and motor development

WHO Child Growth Standards  Construction of standards  Evaluation and field testing of provisional standards  Develop WHO/MGRS software to support individual- and population-based uses  Develop training modules to guide appropriate use  Review interventions to prevent/treat impaired child growth  Develop roll-out strategy with partners, oversee global and country level implementation of the new standards  Adapt global monitoring system for MDG tracking WHO Department of Nutrition for Health and Development

Strategy for promoting healthy growth and development Training on its appropriate appropriate use and use andinterpretation WHO Multicentre Growth Reference Study Development of a sound internationalgrowthreference Clinical and Public Health Interventions

Child survival Physical growth Physical growth Child development Child development WHO Multicentre Growth Reference Study