Why is my child short for their age?

Short stature is when your height is significantly lower than what would be expected for your age and sex. Shortness is most often due to genes that are inherited from your parents. However, sometimes short stature and slow growth can be a sign of an underlying problem such as a hormonal issue, health condition or poor nutrition.

Key points

  1. The height you reach as an adult partly depends on the genes you inherited from your parents, so if your parents are short, you are more likely to be short. Children also grow at different rates and most children who are very short are completely healthy.
  2. A health condition that affects growth is more likely if your child is growing slower than expected, or their rate of growth slows down.
  3. Illnesses or poor nutrition during childhood or being small or premature at birth may also mean children do not reach their full potential adult height.
  4. See your doctor if your child seems to be particularly short compared to other girls or boys of the same age, or if their rate of growth has slowed down.
  5. Sometimes treating an underlying condition or hormonal issue will mean your child can grow to a normal height.

What is the definition of short stature?

Short stature is defined as height that is two standard deviations below the average height for age and sex or more than two standard deviations below the mid-parental height. Your doctor will know how to work out whether your child’s height is outside the normal range for girls or boys their age. 

What are the causes of short stature?

Causes of short stature include:

  • genes for short height inherited from parents
  • delayed growth that is within the normal range
  • a genetic disorder affecting height, such as Down syndrome, Prader-Willi syndrome and Turner syndrome
  • an underlying hormone-related condition, such as not enough thyroid or human growth hormone
  • being born small or premature
  • an underlying condition, such as coeliac disease or inflammatory bowel disease, that affects the ability to absorb nutrients
  • an underlying disorder of the skeleton (skeletal dysplasia)
  • malnutrition from neglect.

Sometimes, the cause is not known.

When should I take my child to a doctor?

See your doctor if your child:

  • seems to be particularly short compared to other girls or boys of the same age
  • is not growing at their normal rate
  • has delayed puberty – in girls puberty is normally before 13 years, in boys before 14 years
  • is being bullied or if their height or growth rate seems to be affecting their sense of wellbeing.

How is short stature diagnosed?

Because there are lots of reasons for short stature, your doctor will do a thorough assessment. They will ask about your child’s birth weight and whether they were premature, as well as the family history of height and timing of puberty. They will examine your child, including measuring their height and working out whether it is outside the usual range for a girl or boy their age.

They will also do blood tests to check their hormone levels and whether there is any underlying illness. They may also arrange an x-ray to check your child’s 'bone age'. They may ask questions about your child’s eating habits and whether they have issues such as loose bowel movements (runny poos), sore tummy, low mood, poor concentration, etc. These symptoms may indicate an underlying condition, such as coeliac disease or inflammatory bowel disease

How is short stature treated?

If your child is short but healthy, they will not need treatment unless it is affecting their mental health, such as because of bullying or delayed puberty. If this is the case, talk to your doctor about getting them some psychological support or find a counsellor or therapist yourself.

If your child has an underlying condition causing short stature, such as coeliac disease or inflammatory bowel disease, the aim of treatment will be to improve the absorption of nutrients. For coeliac disease, this will involve following a strict gluten-free diet. For IBD, anti-inflammatory medicines and dietary modifications may be part of the treatment strategy. Improving absorption of nutrients will help your child to catch up and grow nearer to their potential adult height.

If tests show that your child does not have enough growth hormone, they can be treated with artificial growth hormone, which will help them to catch up and reach a normal height. Growth hormone can help to increase the final adult height of children with Turner syndrome, Prader-Willi syndrome, kidney-disease and some children who were of very low birth weight for their gestational age.

Once the skeleton has stopped growing, there are no drug treatments to increase height. However, some adults have growth hormone treatment to help maintain muscle bulk, a healthy skeleton and normal energy levels. Surgery to stretch legs has risks of complications, which means it is not usually carried out.

How can I prevent short stature?

If short stature has been inherited from your parents, it cannot be prevented. Otherwise, it’s important to follow good nutrition advice for babies and children to support their healthy growth and development. If your child’s rate of growth slows down or if they are noticeably shorter than other girls or boys their age, take them to your doctor. 

If there is an underlying genetic condition, such as Down syndrome, Prader-Willi syndromecoeliac disease or inflammatory bowel disease, there are organisations to support you.

Learn more

The following links provide further information about short stature. Be aware that websites from other countries may have information that differs from New Zealand recommendations.    

Growth and height Society of Endocrinology, UK

References

Credits: Health Navigator Editorial Team. Reviewed By: Dr Fran Mouat, lead clinician for the Starship Paediatric Endocrine and Diabetes Service Last reviewed: 06 Nov 2019