Understanding growth and puberty using the RCPCH UK 2-18 growth charts

Why measure school aged children? Growth is best indicator of health Demonstration of normality of growth by age and stage of puberty Identify disorders of growth Assess obesity

Key questions Is a child too short or tall for their age – could there be a problem? Has puberty started and is it progressing normally? Is growth normal for stage of puberty? Is this child overweight or obese?

The new UK 2-18 charts will help you answer these questions Developed and published by RCPCH Based on updated UK 1990 growth references New design features: Puberty Phases BMI lookup and plotting grid Parental height comparator Adult height prediction

RCPCH UK 2-18 Growth chart Parent height comparator Mid parental centile scale UK90 reference after age 4 WHO standards until age 4 Predicted adult height scale Birth centiles

Using the Adult Height Predictor x Use an X to mark the child’s most recent height centile in the centre line Read off the child’s estimated adult height from right scale 80% of children will be within ±6 cm of this value Scale also shown in feet and inches on left

Using the Parent Height Comparator Mid parental Centile = 75th Mark mother’s height on the left hand scale and father’s height on the right scale using arrows Draw a line between arrowheads and read off mid-parental centile where this crosses the central line Regression adjustment means that children of very short or tall parents have mid parental centile nearer to average than expected

Using the Parent Height Comparator Compare the mid-parental centile to the child’s current height centile (x) Nine out of ten children’s height centiles are within ±two centile spaces of the mid-parental centile Only 1 percent more than three centile spaces below Mid parental centile = 75th X within parental range The child’s most recent height centile up to age 8 gives a good idea of adult height for healthy children. Plot this centile on the height predictor scale to the right of the height chart to find the average adult height for children on this centile. Four out of five children will have adult heights that are within 6cm above or below this value. By also plotting the parents heights on the scale the mid parental height can be read off and compared to the predicted adult height. One in 20 children will have a height more than 2 centile spaces below the mid-parental centile but only 1 in a hundred will be more than 3 centile spaces below. Most of these will have no treatable cause for their short stature, but if there are other concerns about the child’s growth rate a height well below the mid parental centile should be investigated further. The scale can also be used to compare to siblings’ height centiles if wished. X < 5% children < 1% children X

Interpretation of the mid-parental height centile (MPHC) Average centile for all children of these parents Compare to child’s actual height centile Most children are within ±two centile spaces of the mid-parental centile Only 1 percent more than three centile spaces below Most have no treatable cause for their short stature, Investigate further if other concerns about the child’s growth NB a child growing abnormally may still be within mid-parental height range

Body Mass Index (BMI) lookup 91st centile Read weight and height centiles from the growth chart. Plot weight centile (left axis) against the height centile (bottom axis) Read off the corresponding BMI centile from the slanting lines Record centile on grid at top of chart Accurate to ¼ centile space

BMI centile grid: plotting example >91st centile suggests overweight >98th centile is very overweight (clinically obese)

BMI Interpretation A child whose weight is average for their height will have a BMI between the 25th and 75th centiles < 2nd centile may reflect undernutrition, but may simply reflect a small frame or low muscle mass But BMI often varies from one measurement to the next due to measurement error Compare BMI to weight and height centiles using BMI plotting grid at top of chart

Plotting pubertal children on the UK 2-18 Growth charts Pre-puberty ONLY Puberty starting before 8 is precocious Growth during Puberty Plotting pubertal children on the UK 2-18 Growth charts

The 3 Phases of Puberty: from history Pre-puberty (Tanner stage 1) In Puberty (Tanner stage 2-3) Completing Puberty (Tanner stage 4-5) Girls If all of the following: No signs of pubertal development If any of the following: Any breast enlargement pubic or axillary hair If all of the following Started periods with signs of pubertal development Boys High voice and Slight deepening of the voice Early pubic or axillary hair growth Enlargement of testes or penis Voice fully broken Facial hair Adult size of penis with pubic and axillary hair Detailed evaluation of the development of puberty may be made using the five Tanner stages where pre-puberty is Stage 1 and maturity is Stage 5. However, the simpler alternative to evaluating pubertal development is establishing whether the young person is in one of 3 Pubertal phases: If clinical examination is not possible or desirable, then the puberty phase may be ascertained through simple questions about the appearance of the characteristics of sexual development (for example breast development and menarche in girls, pubic hair development (in both sexes) and observation of parameters such as breaking of the voice and facial hair development in boys.

Puberty section of new 2-18 Chart Most healthy children start puberty between these ages Most healthy children complete puberty between these ages Puberty Lines Puberty Lines mark boundaries of normal pubertal development Shaded zone marks area where 0.4th centile varies with phase of puberty Most children plotted to the left of the first puberty line will be prepubertal. Signs of puberty appearing earlier than this may indicate precocious puberty so an assessment will be necessary. Children with ages between the first two puberty lines will either be in Pre-puberty (P) or In-puberty (I). If they have Completed (C) puberty (i.e. have adult sexual development) this may just be early normal pubertal maturation but it could also be abnormally rapid or precocious progression, so a review is indicated. Most adolescents with measurements lying between the second and third puberty lines will either be In-puberty or have Completed puberty. If there are no signs of pubertal development at all, then puberty is delayed and further assessment is necessary. Young adults with measurements plotted to the right of all 3 puberty lines will usually have Completed puberty. If this is not the case, this could mean pubertal progression is delayed and further assessment is needed.

Shaded Puberty Zone Marks area where 0.4th centile varies with phase of puberty Heights in the shaded area below the 0.4th centile: Pre-puberty: if within 2 centiles of Mid-Parental Height = within the normal range In or Completing puberty = below normal range

Summary: 2-18 charts will help you assess The phases of puberty and how to use them to interpret growth charts Predict adult height and relate a child’s height to the parents’ height Assess BMI without a calculator