New UK-WHO growth charts for under 4yrs produced 2009. Uses more data on breast fed infants, hopefully to allow for normal fluctuations cf the growth patterns of bottle fed infants. Separate Preterm section (because 2/52 old term baby is not same as 8/52 old 34/40 ex-preterm. There are no centiles for 0-2 weeks since weight change relative to birth weight is more relevant.
All term babies (37+/40) should be plotted at Age 0.
At 2.5yr you are roughly half your final adult height!
Height velocity should be 4-7cm/yr.
Open circle with dashed horizontal line marks bone age on growth chart.
Tracking is the change in centile between birth and 2 yrs. Later growth should correspond to 2 yr centile. Dangerous diagnosis - does centile lie within range of parents?
2006 WHO child growth standards based on 6 studies from Ghana, India, N America etc. Gives Weight for height Z scores - traditionally, weight for height used for looking at malnutrition (wasting), and expressed as a percentage of median. New standards appear to increase prevalence of severe wasting.
Tools - Abase program for PDA does centiles for various growth parameters. LMSgrowth is an Excel plugin (for PC and Mac) that calculates various data including SD scores for 1 or more children.
Midparental centile: +/- 12.5cm for other sex parent, then +/- 8.5cm for 2 SD (95% confidence interval). This becomes less reliable when parents are unusually tall or short; short parents actually tend not to have not quite such short children as you might expect! Of children below the 2nd centile, MPH explains less than three quarters of them. You should allow for regression to the mean, and aim for a less skewed MPH:
This formula is derived from the regression coefficient from a population study of final heights Charlotte Wright,
This hopefully prevents you assigning short stature to MPH, when a medical/genetic cause is relatively more likely.
Differentiate:
Turners always <75 centile, so don't get worried about mild growth restriction. CAH causes advanced bone age, tall, precocious puberty. Hypoglycaemia test can be done to explore poor growth.
Low dose Synacthen should achieve >500. If Normal dose synacthen also fails then primary adrenal failure is the diagnosis.
Puberty in boys starts only 6/12 after girls but slow to start, quick at finish (Tanner stage G3/4) whereas with girls it's the other way round.
Malcolm's acronym for differential of short stature is NIDSCED:
Otherwise, tends to be:
So do IGF-1, IGFBP-3, TFTs, LH/FSH, Testosterone/Oestradiol, Prolactin, karyotype, bone age (=skeletal maturation, by comparing ossification centres of the left hand/wrist with published standards), pelvic USS, MRI pituitary.
GH secretion is stimulated by GHRH, and inhibited by somatostatin. IGF-1 (Insulin-like growth factor 1) and IGFBP-3 (IGF-binding protein 3) are screening tests, if abnormal proceed to provocative testing (arginine or clonidine). Growth hormone levels are useless, they have diurnal variability, with highest peaks overnight, 46% of the normal statured children had GH levels below 5 µg/L. There is no consensus on definition of GH deficiency, because sensitivity and specificity are exclusive, but peak serum GH response (> 8 to 10 µg/L) to at least two provocative GH stimulation tests would count as normal.
Autosomal Recessive. Pekingese face (midfacial hypoplasia), bossed forehead, adiposity, small penis. MRI v sensitive now.
Delay of growth and puberty. Probably variant of normal. The child (usually a boy, due to more social pressure on boys cf girls) looks young. Bone-age delay of 2-3yrs, usually family history of late puberty and short stature in childhood, normal growth previously.
Provocation tests usually borderline. Bayley-Pinneau tables predict adult height on basis of height, chronologic age and bone age but in those with bone age delay >3yr tend to overpredict height.
Differential is Noonan syndrome (autosomal dominant) - similar physical features to Turner syndrome, but more striking development delay. In boys, cryptorchidism common. Clinical diagnosis, else about half have PTPN11 mutations on 12q. Other syndromes (eg Prader-Willi) likely to have been diagnosed before adolescence.
Diagnosis of exclusion ie growth hormone deficiency, IUGR, syndromes, psychosocial deprivation etc have been excluded. But high dose growth hormone (not licensed) works in these children (although you need to use supraphysiological doses - ?receptor sensitvity problem) - about 2 inches benefit, rarely dramatic. Seems to be safe. £10 000 pa. Increases growth velocity but not many studies looking at final adult height - tends still to be below 5th centile. And in the few studies of quality of life, there is no benefit(see below). Families lose motivation by 2yrs! Sex steroids (under 13yr oxandrolone, over 13yr testosterone) brings final height sooner, but no added height.
Criteria for considering GH for idiopathic short stature:
On meta-analysis 5yrs therapy gives an adult height in the treated group 5 to 6 cm greater than that of the untreated controls and 3.6 to 4.6 cm greater than the height predicted at baseline. Short-term growth velocity increases during growth hormone therapy but is not actually predictive of final height outcome; on the other hand, if no increase in growth velocity is observed with the use of adequate doses, probably no point continuing as adult height is unlikely to increase.
Psychosocial benefit? Neither children with short stature who were referred for growth evaluation nor those screened in population studies had substantial emotional distress or impairment in psychosocial functioning, as compared with peers of normal stature or community norms. Conversely, a recent report described stable psychosocial functioning in children with idiopathic short stature who were treated with either growth hormone or placebo.
N Engl J Med, Volume 354(24).June 15, 2006.2576-2582
Various definitions but consensus is more than 2SDS below median (approx 2nd centile). SGA kids show metabolic programming, with resistance to GH, IGF1 as well as insulin. Hence high risk of Type 2 IDDM later in life.
Some SGA kids esp asymmetrical will show catch up in first year of life. Preterms often show catchup throughout the first 4 years of life! But GH appears to be effective.
Consider from age of 2 (but the earlier, the better). Criteria are:
Expected benefit is 2SD if you start before age 3, perhaps just 1SD if not until 7yr (but still some benefit right up to puberty). Evidence of psychosocial functioning benefit, and even some evidence to suggest better IQ!!!
Continue treating until final height achieved. Theoretical concern of more Type 2 IDDM (as insulin resistance increased by GH) but no evidence so far.
Growth failure due to chronic steroid use in rheumatic disease benefited from GH over 2 years (height and lean muscle mass) - not great improvement in bone mineral density though. (Archives of Disease in Childhood 2006;91:56-60).
Sexual precocity, Marfans, Sotos, 47XYY. Rarely thyrotoxicosis, GH excess.
Defined variously as weight velocity below 5th centile, weight below 3rd centile, or a fall through two centile spaces (over how long!?). Weight for height can be useful but height/length measurements notoriously unreliable. Can be subjective in borderline cases, and all run the risk of over/underdiagnosis. Weight faltering is less perjorative and less negative... Parents are usually pretty concerned about "normal" growth, and link growth to quality of parenting, nutrition (rather than individual/genetic variation) and feel a lot guilt if their child’s growth is "subnormal".
Beware:
Remember that regression towards the mean is seen for very large (and very small) babies, which will imitate failure to thrive. There is also quite a lot of movement away from centile lines particularly in the first 6 weeks.
Contributing factors:
Even though most children with failure to thrive make some recovery, but do not achieve the same final centiles as controls. There is some evidence that IQ is reduced at 1yr, but this is less clearly sustained beyond that time. Which is vaguely reassuring.
Health visitor can do a lot especially with a home visit, and most of the time this should be sufficient - assuming that there is at least some weight gain. A one off paediatric dietician home visit can be more effective than repeat clinic visits: potential areas for tailored intervention can be identified. The dietary history (variety, amounts, history) is often unreliable but can be supplemented by information about mealtime routines, mum's own interest in food/cooking, shopping/budgeting. Typical interventions are:
Give written instructions, and copy to all professionals to encourage consistency and reinforcement.
Investigations have very limited usefulness. Rule out iron deficiency and hypothyroidism?
Charlotte Wright, Arch Dis Child 82(1):5-9, 2000 PMID: 10630901
Measuring parental head circumference (OFC=occipitofrontal circumference) is important for assessing growth of a child's head.
| 97th centile | 3rd centile | |
| Girls at 16yrs | 56.4cm | 52.2cm |
| Boys at 16yrs | 57.7cm | 52.2cm |
Tanner 1978
This work is
licensed under a Creative
Commons
Attribution-Noncommercial-Share Alike 2.5 UK: Scotland License.