Many parents want to know if their child is growing normally or not. A child's growth is considered normal if both the height and weight for his/her age and sex are normal. Although weight is routinely monitored, little importance is given to height of the child. The term short stature refers to any child who has a height well below the average for his/her age and sex. This term is most commonly applied to children whose height, when plotted on a growth curve, is below the line marking the 3rd percentile.
Weight loss in a child indicates an acute medical condition of short duration. However, if a child has short stature, it often indicates that a child has chronic medical condition of longer duration. Such children with proper medical care and appropriate treatment can achieve normal growth.
While change in weight is easily recognized by parents, change in height is not appreciated till the child is significantly short. This is the reason, most experts recommend routine monitoring of not only weight but also height in all children.
How to identify short stature?
Identification of short stature is done by using a growth chart (2015) recommended by the Indian Academy of Pediatrics. This growth chart uses lines to display an average growth path for a child of a certain age, sex, and height. Each line indicates a certain percentage of the population that would be that particular height at a particular age. A boy with a height that is plotted on the 25th percentile line, for example, indicates that approximately 25 out of 100 boys of his age are shorter than him. A child that has a height plot that is below the 3% line is considered to have short stature. Such children need evaluation by a pediatric endocrinologist or a growth specialist to identify the cause of short stature.
How is short stature assessed?
Growth specialists take many things into account while assessing your child's growth. The height of the parents is an important indicator of how tall a child is likely to grow as an adult. The term mid-parental height refers to the height that a child is likely to achieve as an adult and is calculated by a simple formula based on parent's height. A child born to parents who are short will most likely grow with final adult height below average. Growth specialists also take into consideration the values of a child's growth referred to as the growth velocity. Growth velocity of a child aged 4 to 10 years is fairly constant between 4 - 6 cms per year. If the growth velocity drops, it indicates that the child has some cause of growth failure and needs immediate attention.
What are the causes for short stature?
A child can remain short due to any of the following reasons:
- Familiar short stature - if one or both parents are short
- Constitutional delay in growth and puberty - In this condition, the child remains short but has late catch up of growth and achievement of normal adult height. Identification of this condition needs expertise
- Chronic medical conditions
- Endocrine conditions like growth hormone deficiency, thyroid hormone deficiency, etc
- Genetic conditions
- Medications like steroids used for arthritis or asthma
- Poor nutrition
- Babies with a history of being born small (small for gestational age or with a history of intrauterine growth retardation)
- Idiopathic short stature
What tests are done for short stature?
The best "test" is to monitor the child's growth over time using the growth chart. Six months is a typical time frame for children, and if the rate of growth is clearly normal no additional testing may be needed. If growth velocity is less or if the child is severely short, growth specialists will do certain tests to assess the cause of short stature as mentioned above. Your growth specialist may also ask for bone age assessment which is done by taking an X-ray of the left hand and the wrist.
How is short stature treated?
The treatment depends on the nature of underlying condition, e.g., thyroxine supplementation for thyroxine deficiency, growth hormone supplementation for growth hormone deficiency.
When is Growth Hormone indicated?
Growth hormone is indicated only if growth hormone deficiency is confirmed biochemically by special tests. Treatment with growth hormone in such children increases their height by 8 - 13 cm in the first year of treatment. Growth hormone is also approved for medical conditions other than growth hormone deficiency like idiopathic short stature, turner syndrome, chronic kidney disease, small for gestational age babies, etc.
To summarize, height is also one of the important measurements to assess child's growth. Early and appropriate treatment helps in catching up with the growth for such children.