How It Is Calculated?

The kid's weight, height, and head circumference are all compared against the WHO Growth Standards. These standards are formed by taking the average of healthy boys and girls of the same age and gender. There are percentiles corresponding to each individual parameter which express the child's growth against the others. One single measurement gives you a snapshot while multiple measurements taken over a period of time reveal the growth patterns and help determine if the child is growing in the expected way.

Measurement Procedure

Weight

• The best way to do it is by using a digital baby scale.
• For the most accurate result, baby should be weighed without any clothing or a diaper.
• If a standard scale is being used, weigh yourself first, then weigh yourself with the baby and subtract the first reading from the second one.

Height or Length

• For infants, lying down is the way to go. Make sure their head is straight and feet are together with their heels on the ground.
• In the case of older kids, have them stand barefoot against a wall with their toes together and eyes looking straight ahead.
• Note down the height in either cm or m using a tape measure and rounding it off to the nearest 0.1 cm.

Head Circumference

• A flexible measuring tape is recommended.
• Position it on the eyebrows and wrap it around the thickest part at the back of the head.
• Not tight but snug, and measure to the nearest 0.1 cm.

It is very important that you always record the date, the age in months, and the measurement value for the follow-up.

When To Be Worried

• Weight or height gain not increasing
• Measurements that fall below the third percentile or above the ninety-seventh percentile
• Head circumference increasing too slowly or too fast
• Poor appetite, lethargy, chronic tiredness or recurrent illness.
• Significant decline in percentile scores at any time

Reference

WHO Child Growth Standards

WHO Anthro Measurement Guide

Indian Academy of Pediatrics Growth Monitoring Guidelines