Assessment of Growth and Growth Charts by WHO

Assessment of growth and the use of growth charts are crucial topics in pediatrics 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 for a quick overview of this important pediatrics topic for NEET PG/NExT exam preparation.

What is GROWTH?

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

Different terminologies in different periods of life

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

Important Anthropometric Parameters Anthropometry

It is a measurement of various parameters in a human being. ‘Anthro’ means human, and ‘meter’ refers to measurement. To assess a child's growth, we use different anthropometric parameters like weight, height, head circumference, mid-arm circumference, skin fold thickness, chest circumference, and body mass index. These are 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 the acromion and olecranon process and take the circumference of that region using a non-stretchable tape with milli-meter marking.

While measuring mid-arm circumference, the child's arm should be hung loosely. The arm muscle should not be very contracted.

Normal MAC in Neonate

• Term Neonate : 9-11 cm
• By the end of 1^st year: 16cm
• Between 1-5 years of age: increases by 0.25 cm/year. That is why MAC is referred to as an age-independent anthropometric parameter at this age.
• These are predictive values. For exact values, there are charts available:

1. Tanners chart was used previously to get the normal value of MAC for different age groups. 
2. WHO growth chart-currently used, to get the normal value of MAC at different age groups

Shakirs tape

The 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, it indicates borderline nutritional status. If MAC falls in the green zone, it indicates normal nutrition.

Skin Fold Thickness (SFT)

Skin fold thickness gives an idea about the amount of subcutaneous fat in the child. The device used to measure SFT is called the the Harpenden callipers device. The areas to measure SFT are suprascapular, subscapular, biceps, and the triceps area. The normal value of the SFT is taken from the WHO growth chart. Usually, the subcutaneous fat content is maximum at around 9 months of age, and then it starts decreasing until 6 years of age, and then it starts increasing.

Chest Circumference (CC)

At birth, the head circumference (HC) is more than CC. In a well-nourished child, the HC becomes equal to CC by 9 months to 1 year of age. 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 the 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. The 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 countries across the world: Brazil, Oman, Norway, Ghana, the US, and India. (Mnemonic BONGUI). The children who were exclusively breastfed in the first few months of life. Babies who had factors like maternal smoking or alcohol intake were excluded. WHO includes 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 can the growth of a child be assessed?

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

To learn this important pediatrics topic in detail, along with other high-yield topics, download the PrepLadder app. The app provides access to engaging video lectures and self-explanatory study notes.

Frequently Asked Questions

Q: What is Tanner's chart?

Answer: Tanner’s chart is used to get the normal value of mid-arm circumference at different age groups.

Q: What is Skin fold thickness?

Answer: The skin fold thickness gives an idea about the amount of subcutaneous fat in the child. 

Q: What device measures the Skin Fikd Thickness?

Answer: The device used to measure SFT is called the Harpenden calipers device.

Q: What is Growth?

Answer: Growth refers to an increase in physical size.

To learn this important pediatrics topic in detail along with other high-yield topics, download the PrepLadder app and get access to engaging video lectures and self-explanatory study notes.