Assessment of Growth and Growth Charts by WHO

Assessment of growth and the use of growth charts are crucial topics in paediatrics for the early detection of growth problems. Growth assessment helps identify growth problems early on, allowing for early intervention and treatment. This can prevent or minimize the long-term consequences of growth problems.

The World Health Organization (WHO) growth charts are widely used around the world as a standard reference for growth assessment. This ensures consistency in growth monitoring and facilitates comparison of growth patterns across different populations.

Read this blog further for a quick overview of this important pediatrics topic for NExT/NEET PG exam preparation.

What is GROWTH

Growth refers to increase in physical size. The baby continues to grow right from its conception, so different terminologies were given to name at different points of time.

Different terminologies in different periods of life

• Embryo- First 8 weeks of intrauterine life
• Fetus-9 week to birth of baby
• Neonate-First 28 days of life
• Infant- Throughout first year of life
• Toddler- 1-3 year age group
• Preschool - 3-6 years of age
• Adolescent- 10-19 year of age

Important anthropometric parameters Anthropometry

Is a measurement of various  parameters in a human being. Anthro means human and metry refers to measurement. To assess the growth of a child we use  different anthropometric parameter like: weight, height, head circumference, mid arm circumference, skin fold thickness, chest circumference and body mass index. These are the important factors

Mid arm circumference (MAC) or Mid upper arm circumference (MUAC)

• It is the circumference of the middle point of the arm. To get the middle point of the arm , mark the most prominent area that is the lateral aspect on the shoulder ( acromion process) and then ask the child to fold the elbow , after folding , mark the most prominent area ( olecranon process). With measuring tape , find the midpoint between acromion and olecranon process and take circumference of that region using a non stretchable tape with milli meter marking
• While measuring mid arm circumference, the arm of the child should be hung loosely. The muscle of the arm should not be very contracted.

Normal MAC in Neonate

• Term Neonate : 9-11 cm
• By end of 1^st year: 16cm
• Between 1-5 years of age: increases by 0.25 cm / year. That is why in this age MAC is referred to as age independent anthropometric parameter

These are predictive values, for exact values there are charts available:

1. Tanners chart- used previously, to get the normal value of MAC at different age groups. 

2. WHO growth chart-currently using, to get normal value of MAC at different age groups

Shakirs tape

Device used by health workers in the field to measure MAC. It is a color coded tape that has red (<11.5), yellow (11.5-12.5 cm) and green zone (>12.5cm). If MAC is falling in the red zone that shows the child has severe malnutrition. This is applicable to children between 6 months - 5 years of age.If MAC falls in the yellow zone, indicates borderline nutritional status. If MAC falls in the green zone indicates normal nutrition   

Skin Fold Thickness (SFT)

Gives an idea about the amount of subcutaneous fat present in the child. The device used to measure SFT is called Harpenden callipers device. The areas to measure SFT is suprascapular, subscapular, biceps and the triceps area. Normal value of the SFT gets from WHO growth chart. Usually the subcutaneous fat content is maximum at around 9 months of age and than it starts decreasing till 6 years of age and than it starts increasing

Chest Circumference (CC)

At birth the head circumference (HC) is more than CC. By 9 months to 1 year of age the HC becomes equal to CC in a well nourished child. In a normal child beyond 1 year of age CC will be more than HC. CC is usually measured with a measuring tape at the level of the child's nipples. 

Body Mass Index (BMI)

It is a composite of the weight and the height of the child. 

BMI=wt(kg)/ht(m)^2. If the BMI of the child is < 5^th percentile, that indicates that the child is underweight , but if it is > 85^th percentile, it indicates overweight. If > 95^th percentile, then it indicates obesity.

Growth charts

Graphical representation of the anthropometric parameters. At every visit it is mandatory to plot the growth of the child in growth chart

International Growth Charts

1. NCHS (National Centre for Health Statistics)- came in 1977
2. CDC- came in 2000
3. WHO - published in 2006. Most important and preferred growth chart for <5 children all over the world

WHO Growth Chart

Based on the MGRS (Multicentre Growth Reference study). This study included children from 6 different countries across the world Brazil, Oman, Norway, Ghana, US, India. (Mnemonic BONGUI). The children who were exclusively breastfeed in the first few months of life. Babies who had factors like maternal smoking or alcohol intake were excluded. WHO include growth charts for various parameters like

• Wt for age
• Ht for age
• Wt for Ht
• HC for agr
• MAC for age
• BMI for age
• SFT for age 
• Charts for major motor development milestones
• Separate charts for boys and Girls which are color coded
• Percentile based charts as well as Standard deviation or z score based chart

Indian Growth Charts

Used beyond 5 years of age. Includes K. N Agarwal growth chart, IAP (Indian Academy of pediatric), Khadilkar chart

How to assess the growth of a child?

1. Decide which anthropometric to use like beyond 6 years measures only Ht, Wt and BMI
2. Choose appropriate device
3. Plot on growth charts or compared with normal expected value for that age  
4. Interpret

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