Down’s syndrome

Last updated:

Reviewed by:

Dr Bryony Henderson

, Lead GP at Livi

Medically reviewed

Down’s syndrome is when someone is born with an extra chromosome. This is usually down to chance – because of a change in the sperm or egg before birth. The extra genetic material can cause physical and developmental changes.

What is Down’s syndrome?

Down’s syndrome means that a person has an extra chromosome in their 21st pair of chromosomes. Usually, a person is born with 46 chromosomes and 23 pairs. A baby born with Down’s syndrome has 47 chromosomes. 

These extra chromosomes can alter how a baby’s body and brain grows, and can lead to some level of learning difficulty.

What causes Down’s syndrome?

Down’s syndrome is caused by a random error during cell division, known as ‘nondisjunction’, which results in an extra chromosome in the 21st pair.

There’s no evidence of any environmental factors or parental factors. Down’s syndrome doesn’t happen because of anything anyone did before or during pregnancy, and it’s also not hereditary, so it doesn’t pass down through families.

The risk of Down’s syndrome can increase with the age of the parents at the time of conceiving.

How is Down’s syndrome diagnosed?

During pregnancy, you’ll be offered screening for Down’s syndrome at around 10-14 weeks of your pregnancy. However, it’s your choice whether to have screening tests or not. The screening involves an ultrasound known as a dating scan.

The dating scan will monitor the development of your child as well as look for any signs of Down’s syndrome in the baby. The dating scan involves taking a blood test as well as measuring the fluid at the back of the baby’s neck. This test will also look for 2 other syndromes: Edwards and Patau’s. 

When a screening test results in a positive result, a doctor will usually carry out further testing to confirm the diagnosis of Down’s syndrome.

What are the symptoms of Down’s syndrome?

People with Down’s syndrome can generally live a normal life, they may just need some extra support. Everyone with Down’s syndrome will experience the condition differently.

What support is available for new parents?

It’s important to remember that babies with Down's syndrome are like any newborn babies. Some babies with Down's syndrome might need extra help, like with feeding.

Children with Down's syndrome may have some level of learning disability, but they will have their own personalities and learn at their own pace. 

There's support available for you and your baby. A good place to start is the Down's Syndrome Association. They have a helpline and email address.

Medical support

Children with Down's syndrome should have regular check-ups with a doctor, as there are conditions they may be more likely to have. It might be helpful for them to work with the following specialists:

  • A speech and language therapist for help with speaking

  • An optician or hearing specialist for help with vision and hearing

  • A physiotherapist for help walking and moving if they need

When should I speak to a doctor about Down’s syndrome?

You can speak to a GP or health visitor for support or to find out how to access the above services if you need them.

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi