Growth Charts

Growth charts are essential tools for monitoring the growth and development of children. Various types of charts have been developed and used over time:

• Road to Health Chart:
  • Popularized by David Morley, these charts are used for growth monitoring in well-baby clinics and ICDS programs.
  • They visualize weight measurements over time; an upward curve indicates a healthy trajectory (green zone), while flat or downward curves indicate concern (yellow or red zones).
• Percentile Charts (NCHS/CDC):
  • Developed by the National Center for Health Statistics (NCHS) and CDC.
  • These represent the position of a measurement in a bell-shaped distribution (Gaussian curve).
  • The 50th percentile is the median. The CDC 2000 charts are considered "references" describing how a population grows on average, rather than how it should grow,.
• WHO Child Growth Standards (2006):
  • These are currently the recommended charts for children from birth to 5 years.
  • They are based on the Multicentre Growth Reference Study (MGRS) and serve as a "standard" (prescriptive) rather than a "reference" (descriptive).
• ICMR Standards:
  • Indian Council of Medical Research (ICMR) standards exist but are often considered to have unacceptably low values compared to international standards.
• Mother and Child Protection (MCP) Card:
  • Widely used in India (also known as Mamta Card).
  • It contains pre-printed growth curves (WHO standards) to track weight-for-age and serves as a counseling and family empowerment tool,.
• ELIZ Health Path:
  • A chart designed for adolescents that incorporates weight, height, and BMI in a single chart to diagnose undernutrition and obesity.
• Specialized Charts:
  • Available for specific conditions like Down syndrome, Turner syndrome, and Achondroplasia, as standard charts may not apply.

WHO Growth Charts (2006)

The World Health Organization (WHO) growth charts are the global gold standard for assessing the growth of children up to 5 years of age.

Background and Methodology (MGRS)

• Study Population: The charts were derived from the Multicentre Growth Reference Study (MGRS) conducted between 1997 and 2003.
• Participating Countries: Data was collected from six countries: Brazil, Ghana, India, Norway, Oman, and the United States.
• Inclusion Criteria: Children were selected from favorable socioeconomic environments with no constraints on growth. Crucially, they were healthy term infants who were exclusively or predominantly breastfed for at least 4 months and continued breastfeeding for at least 12 months,.
• Prescriptive Nature: Unlike previous charts (like NCHS) which were descriptive (how children do grow), the WHO charts are prescriptive (how children should grow) when their nutritional and health needs are met,.
• Breastfeeding as Norm: The study established the breastfed infant as the biological norm for growth.

Key Features and Parameters

• Longitudinal and Cross-sectional: The study combined longitudinal follow-up from birth to 24 months with cross-sectional data for children aged 18 to 71 months.
• Parameters Measured:
  • Weight-for-age
  • Length/Height-for-age
  • Weight-for-Length/Height
  • Body Mass Index (BMI)-for-age (provided for children under 5 years for the first time).
  • Head circumference
  • Mid-upper arm circumference (MUAC)
  • Subscapular and triceps skinfold thickness.
• Motor Milestones: Uniquely, the study linked physical growth with key motor milestones like sitting, standing, and walking.

Interpretation and Classification of Nutritional Status

The WHO charts use Z-scores (Standard Deviation scores) to classify nutritional status.

• Weight-for-Age (Underweight):
  • Normal: -2 SD to +2 SD.
  • Underweight: < -2 SD.
  • Severely Underweight: < -3 SD,.
• Height/Length-for-Age (Stunting):
  • Normal: -2 SD to +2 SD.
  • Stunted (Chronic Malnutrition): < -2 SD.
  • Severely Stunted: < -3 SD,.
• Weight-for-Height/Length (Wasting/Overweight):
  • Normal: -2 SD to +2 SD.
  • Wasted (Acute Malnutrition/MAM): < -2 SD to -3 SD.
  • Severely Wasted (SAM): < -3 SD,.
  • Overweight: > +2 SD (in children under 5).
  • Obese: > +3 SD (in children under 5).

Comparison with NCHS/CDC Charts

• Feeding Mode: WHO charts are based on breastfed infants, while NCHS charts included a significant number of formula-fed infants.
• Growth Trajectory: Healthy breastfed infants tend to grow rapidly in the first few months but grow slower than formula-fed infants later in infancy. Consequently, WHO standards show a faster initial growth rate but a slower rate subsequently compared to NCHS references.
• Standard vs. Reference: WHO charts define optimal growth (Standard), whereas CDC charts describe how the population grew at a specific time (Reference).