UK-WHO Growth Charts - Fact Sheet 6
Plotting and assessing infants and toddlers up to age 4 years This fact sheet covers the plotting and assessment of infants and toddlers from the age of 2 weeks onwards. Topics in this fact sheet include … Knowing how often and when to weigh Normal rates and variations of growth or weight gain Length centile changes at 2 years Adult height prediction and BMI look up
When to weigh and measure After the neonatal period and once feeding is established, babies usually need only be weighed at around 8, 12 and 16 weeks and at 1 year; at the time of routine immunisations or checks. If there is concern, weigh more often, but in general weighing at intervals too close together is misleading. This means that well babies should be weighed no more than: once a month before 6 months once per two months aged 6-12 months once per 3 months over age one year
Most children do not need to be weighed this often
Head Circumference, Length or height should be measured: For children Whenever there are any worries about over two a child’s weight gain, growth or general calculate body health mass index to th help you tell If the weight is below the 0.4 centile If there is very rapid weight gain If the weight is above the 99.6th centile
whether the child is relatively over or underweight
In addition, head circumference should be measured: Around birth, but measurements taken in the first 24hours are unreliable as the head will have been subjected to moulding
What is a normal rate of growth? Length/Height It is often difficult to get an accurate measurement of length or height in an uncooperative baby or toddler, so successive measurements commonly show wide variation. It is therefore important not to place too much reliance on single measurements or apparent changes in centile position between just two measurements. If there are worries about growth (or weight gain) it is a good idea to measure on a few occasions in order to get a sense of the child’s average centile and healthy children will generally show a stable average position over time. If after a number of measurements there seems to be a consistent change in centile position by more than one centile space, the child should usually be assessed in more detail. All children below the 0.4th centile should be assessed by a Paediatrician at some stage even if apparently growing steadily. Head circumference The head circumference centile may show some variation over time, but most measurements track within one centile space and fewer than 1% of infants drop or rise through more than 2 centile spaces after the first few weeks. Very rapid head growth with upward centile crossing can be a sign of hydrocephalus or other problems while slowing of head growth, with a fall down the centiles may also be a sign of underlying problems of brain or skull growth and development. If there is a fall or rise through 2 or more centile spaces, the child should be carefully assessed.
Body Mass Index (BMI) conversion chart Body mass index (BMI) tells you how heavy a child is relative to their height and is the best measure of fatness and thinness from the age of 2, when height can be measured fairly accurately. The BMI conversion chart provides an approximate BMI centile accurate to a quarter of a centile space.
At the 8 week check At any time after that if there are any worries about the child’s head growth or development
What is a normal rate of weight gain? As the new charts allow for the normal slower pattern of weight gain up to age 2 weeks, on average, children will be on the same centile at 2 weeks as at birth. This is different from previous charts where children appeared to drop half a centile space between birth and 2 weeks. After the neonatal period weights usually track within one centile space, but individual measurements often show wide variation. Acute illness may be accompanied by weight loss and weight centile fall. However, a child’s weight usually returns to its previous centile within 2 to 3 weeks. Less than 2% of infants show a sustained drop through two or more weight centile spaces on the new WHO charts. If such a drop occurs, the child should be assessed in more detail. © 2009 Royal College of Paediatrics and Child Health www.growthcharts.rcpch.ac.uk
BMI = 91st
How to calculate and plot BMI 1. Read off the weight and height centiles from the A4 chart. 2. Plot the weight centile (left axis) against the height centile (bottom axis) on the BMI conversion chart. 3. Read off the corresponding BMI centile from the slanting lines. 4. Record the centile with the date in the data box underneath the lookup.
Interpreting Body Mass Index (BMI) •
BMI above the 91 centile suggests that the child is overweight th
BMI above the 98 centile is very overweight (clinically obese) and is usually associated with excess fatness
BMI below the 2nd centile is unusual and may reflect undernutrition, though it may also be seen in children with unusual body shapes, particularly if they have chronic illness or disability
Length to height change at 2 years Measure length up to age 2, and height from then on. A child’s height is usually slightly less than their length since when a child is measured standing up the spine is squashed a little compared with lying down.
For example, if a boy’s height is mid-way between the 50th and the th 75 centile, the corresponding centile on the Adult Height Prediction scale (see right) suggests his adult height will be 179 cm (5 foot 10½ inches). The prediction has a range of uncertainty such that four-fifths of boys will be within plus or minus 6 cm of the predicted value. So there is a four-fifths chance that his height will be between 173 and 185 cm. The prediction has a range of uncertainty such that four-fifths of boys will be within plus or minus 6 cm of the predicted value. So there is a four-fifths chance that his height will be between 173cm and 185cm, i.e. between 5 feet 10½ inches and 6 feet one inch.
A child whose weight is average for their height will th th have a BMI between the 25 and 75 centiles (whatever their height centile)
Adult height prediction
The adult height prediction differs from the target height calculation on the UK1990 height chart. Target height compares the child’s height with those of their parents, and identifies children who are unusually tall or short compared to their parents. The adult height prediction tool provides a good prediction of adult height for most children, including those who are unusually tall or short, but it does not compare them with their parents.
Summary Plotting and assessing infants and toddlers: Weigh at the time of routine immunisations / checks Measure length or height and head whenever concerned about weight gain, growth or development Any child with measurements consistently below the th 0.4 centile should be assessed in more detail th If weight is above the 99.6 centile BMI should be calculated using BMI conversion chart Adult height can be predicted from recent height centile using the adult height predictor
Further reading Cole TJ. 1997. Growth monitoring with the British 1990 growth reference. Archives of Disease in Childhood 76 No 1:47-9.
The centile lines on the chart shift down slightly at age 2 to allow for this. It is important that this transition does not worry parents; what matters is whether the child continues to follow their new centile position after the transition.
Cole TJ. 2002. A chart to link child centiles of body mass index, weight and height. Eur J Clin Nutr 56(12):1194-9. Wright CM, Waterston A, Matthews JNS, Aynsley-Green A. 1994. What is the normal rate of weight gain in infancy ? Acta Paediatrica 83:351-6. Wright C, Avery A, Epstein M, Birks E, Croft D. 1998. New chart to evaluate weight faltering. Arch Dis Child 78(1):40-3.
© 2009 Royal College of Paediatrics and Child Health www.growthcharts.rcpch.ac.uk