Assessing growth is a key component of the paediatric exam. The measurement of height, length, weight and head circumference appears deceptively simple but requires accuracy, adaptability of method and patience to ensure it is done correctly.
With all children, don’t expect to follow a pre-defined order. Be creative and playful, making the examination into a game involving parents, siblings and the toys available to you.
Wash your hands
Introduce yourself to both the parents and the child.
Explain what the growth assessment will involve and explain why the measurement is required.
Gain consent from the parents/carers and/or child before proceeding.
Today I’d like to measure your child’s height (or length), weight and head circumference, which will involve the use of scales, a standing ruler (or measuring board – as appropriate) and a tape measure.
Are you happy for me to carry out the examination?
Children less than 2 years old should be measured supine (lying down, facing upwards).
Children unable to stand, or who find standing difficult, due to illness/physical disability should also be measured supine.
If the child is known to have one leg shorter than the other, they should be measured standing on the longest leg. They should always be measured on the same leg.
The following should be removed:
Hair clips and braids (undo braids)
Two people are generally required to measure a child when supine.
Play and distraction techniques may be useful to keep the child comfortable and entertained during what can be a distressing moment of measurement.
An appropriate measuring board/Rollametre should be placed on a firm and flat surface.
Measurement of supine length
Lay the child on the board.
One person should ensure the head is supported (in contact with the headboard) and is in the correct position (the corner of the eyes horizontal to the middle of the ear – looking straight up at the ceiling). This is a great job for the parent/carer, helping to also minimise distress for the child being held in this position.
The other person should position the child:
Heels touching the backplate of the measuring instrument
Legs straight and in alignment with the body
Buttocks against the backboard
Scapula against the backboard if possible
The ankles should be supported, and this position maintained
Record the measurement to the last complete millimetre.Don’t round up or down.
A child is weighed naked up to 2 years old. Appropriate baby scales should be used.
Ensure the nappy is removed.
After 2 years of age, light clothesonly should be worn. Shoes or slippers should be removed and pockets emptied of their contents.
Appropriate sitting or stand on scales should be used.
If the child is weighed with additional equipment (i.e. splint/cast, medical equipment or dressing), this should be documented.
As with height/length, it is often easier if two people are involved in the process of weighing a child. This may include the parent/carer if they are willing to assist.
Again, play and distraction techniques may be useful throughout the measurement of weight.
If appropriate, ask the parent/carer to place the child on suitable scales. The child must be placed completely on the scales and their weight fully borne.
For a distressed child, the carer can be asked to stand on the standing scales, the scales then zeroed with the carer still standing on them, and the child handed to the parent. The scale should then show the child’s weight.
Alternatively, the child can be measured with the carer on sitting scales. The weight of the carer with the child should be measured, then the carer’s weight subtracted.
Record the figure on the scale to the last complete gram for neonates or children <4kg and to the last 100g for older children or if >4kg. Do not round the measurement up or down.
The child should then be redressed and left comfortable.
A Lasso-o™ is the recommended equipment used to measure head circumference as per RCPCH guidelines.
The child’s hairstyle should allow for accurate measurement – i.e. remove plaits or braids and remove any hair adornments. If these are not removed – this must be documented.
Again, play and distraction techniques may be useful throughout the measurement process.
Before using the measuring tape:
Consider the general clinical condition (e.g. is the child irritable or vomiting)
Observe the state of the fontanelle (open, closed, full, tense, soft or dipped)
Note the shape of the child’s head (i.e. craniosynostosis, or a low hairline, e.g. Saethre-Chotzen syndrome).
Measurement of head circumference
Loop the Lasso-o™ and place over the child’s head.
The tape should be placed above the ears and midway between the eyebrows and the hairline, to the occipital prominence at the back of the head (the aim is to measure the largest circumference possible).
Pull the Lasso-o™ or measuring tape taut so that any hair is compressed.
Read the measurement from the appropriately marked place. This should be taken to the nearest millimetre.
Repeat the procedure above to ensure the accuracy of the measurement.
Note 1: If the child does have an abnormally shaped head, the tape should be placed over the largest measurable circumference. This should be documented against the recorded measurement.
Note 2: A separate head circumference chart is available for children with achondroplasia and trisomy 21.