What is Down's syndrome?

Down's syndrome is when you're born with an extra chromosome.

You usually get an extra chromosome by chance, because of a change in the sperm or egg before you're born.

This change does not happen because of anything anyone did before or during pregnancy.

What it's like to have Down's syndrome

People with Down's syndrome will have some level of learning disability. This means they'll have a range of abilities.

Some people will be more independent and do things like get a job. Other people might need more regular care.

But, like everyone, people with Down's syndrome have:

  • their own personalities
  • things they like and dislike
  • things that make them who they are

Having a baby with Down's syndrome

In almost all cases, Down's syndrome does not run in families.

Your chance of having a baby with Down's syndrome increases as you get older, but anyone can have a baby with Down's syndrome.

Speak to a GP if you want to find out more. They may be able to refer you to a genetic counsellor.


If you're pregnant you'll be offered a screening test to find out your chance of having a baby with Down’s syndrome.

You can have the test at your dating scan (around 11 to 14 weeks).

If you have a higher chance, you can have further tests.


It's your choice whether or not to have any screening tests.






^^ Back to top


All children born with Down's syndrome have some degree of learning disability and delayed development, but this varies widely between individual children.

Delayed development

Children with Down's syndrome may be slower to learn skills like sitting, standing, walking and talking. They'll develop these skills eventually, it just takes more time.

Some children with Down's syndrome may have more complex needs. For example, they may also be autistic or have attention deficit hyperactivity disorder (ADHD).

Children with Down's syndrome often need more support as they grow up, including extra help at school.

Physical characteristics

People with Down's syndrome have more in common with their families than with other people with Down's syndrome.

Just like the rest of the population, they'll inherit their families' characteristics.

Health conditions

Some conditions are more common in people with Down's syndrome.

These include heart conditions and problems with hearing and vision.


^^ Back to top

Who can get it

Down's syndrome is a genetic condition that happens as a result of an extra chromosome (chromosome 21).

Chromosomes explained

Our bodies are made up of cells that contain genes. Genes are grouped in thread-like structures called chromosomes.

These contain detailed genetic instructions for lots of different things, including:

  • how a baby's cells develop
  • their gender
  • their eye colour

Usually, cells contain 46 chromosomes: 23 from the mother and 23 from the father.

In people with Down's syndrome, all or some of the cells in their bodies contain 47 chromosomes instead, as there's an extra copy of chromosome 21.

In most cases, Down's syndrome is not inherited and it's just the result of a one-off genetic change in the sperm or egg.

What are the chances of having a baby with Down's syndrome?

With every pregnancy, there's a small chance of having a baby who has Down's syndrome.

Some people are more likely to have a child with Down's than others.

The main thing that increases the chance of having a baby with Down's syndrome is the mother's age.

For example, a woman who is:

  • 20 years old has a 1 in 1,500 chance
  • 30 years old has a 1 in 800 chance
  • 35 years old has 1 in 270 chance
  • 40 years old has a 1 in 100 chance
  • 45 years old has a 1 in 50 or greater chance

But babies with Down's syndrome are born to women of all ages.

Your chance of having a child with Down's syndrome is also increased if you previously had a child with Down's syndrome.

For most people, this chance is still small (around 1 in 100).

There's around a 1 in 2 chance of a child having Down's syndrome if one of his or her parents has the condition.

^^ Back to top

Living with

With help and support, most people with Down's syndrome are able to have healthy, active and more independent lives.

New parents

If you've recently found out your baby has Down's syndrome, you may be feeling a whole range of emotions, including fear, joy, sadness, or confusion. There's no right or wrong way to react.

It's important to remember you're not alone in your situation. Thousands of people in the UK have Down's syndrome. There are also lots of people who have experience of supporting and caring for people with the condition.

Lots of new parents find it reassuring to talk to other parents. The Down's Syndrome Association can put you in touch with another family who have a child with Down's.

They can share their experiences with you, offer you advice, and talk through any fears or concerns you may have.

Read more information for new parents on the Down's Syndrome Association website.

Helping your child

Most children with Down's syndrome have difficulty learning new things and take a bit longer to reach developmental milestones, such as walking and talking.

There are various things you can do to help your child with their learning and development.

Things that may be useful include:

  • using play to help your child learn – for example, show them how to play with their toys, and use toys to encourage them to reach, grasp, and move
  • naming and talking about things your child's looking at and is interested in
  • giving your child the opportunity to mix with other children
  • encouraging your child to be as independent as possible from an early age with things like feeding and dressing, getting ready for bed, brushing teeth, and going to the toilet
  • playing games to teach new words – a home visiting teacher or speech and language therapist can give you some ideas

It's important to find a balance between "special" activities and all the normal things families do.

As with all new babies, at times they'll need to fit in with what's going on around them.

Not everything you do with your baby needs to be educational or meaningful. Any fun activity with the family can be beneficial.

Professional support

A number of different professionals experienced in caring for children with Down's syndrome will be able to help you with any difficulties you or your child are having.

For many people this will involve an early intervention programme. This is a special programme that aims to help a child with learning disabilities develop, as well as provide support to the family.

An early intervention programme can include:

  • speech and language therapy – to help with any problems communicating or feeding
  • physiotherapy – to help with any muscle weakness or movement difficulties
  • individual home teaching programmes

You'll be advised about things you can do at home to help your child learn and develop. You'll also be able to find out about your child's condition and meet other families like yours.

You can also call the Down's Syndrome Association helpline on 0333 121 2300 for advice.

Financial support

You may feel you need to give up work or decrease your hours so you can spend more time caring for your child.

If this is the case, it's worth finding out about any benefits you may be entitled to.

Read about financial help for parent carers.

Regular health check-ups

Children and adults with Down's syndrome need regular check-ups to monitor their health.

These check-ups will usually be with a paediatrician (a children's doctor) at first. Your GP may do them as your child gets older.

The health check-ups may involve:

  • hearing and vision tests
  • measuring height and weight
  • blood tests to check for thyroid problems
  • checking for signs of heart problems

If your doctor spots any possible problems, they can refer you to a specialist.

School and your child

Lots of children with Down's syndrome are educated in mainstream nurseries or schools with support.

But individual needs vary, and some parents feel a special school will be most suitable for their child.

It might help to visit some mainstream and special schools in your local area. Talk to the staff about how they would meet your child's special educational needs.

You can also find out more about education on the Down's Syndrome Association website.

Teens with Down's syndrome

Until the age of 18, child health and social care services are responsible for the care of children with long-term health conditions like Down's syndrome.

From 18, it's usually the responsibility of adult services. Between the ages of 16 and 18, your child will start a "transition" to adult services.

For more information, read about transition planning for disabled young people.

Adults with Down's syndrome

Further education and employment

Lots of young adults with Down's syndrome pursue further education, and many go on to work.

Living independently

With help and support, lots of adults with Down's syndrome can lead an active and fairly independent life.

Although it may not be possible to live completely independently, some adults with Down's syndrome leave home and live in their communities with support.

Adults with Down's syndrome often move into property owned and staffed by a housing association. Staff can provide different levels of support depending on the person's particular needs.

If necessary, a social worker may be able to help with finding accommodation. An occupational therapist can offer practical advice to help make independent living easier.

Relationships, sex and fertility

Lots of people with Down's syndrome have loving relationships, although they may need some support when it comes to things like contraception.

Men and women with Down's syndrome tend to have lower fertility. This doesn't mean they can't have children, but it does make it more difficult.

Those who decide to have children will usually need specialist guidance and support to help them cope with the demands of a new baby.

If one partner in a couple has Down's syndrome, there's around a 1 in 2 chance of each of their children having Down's syndrome, too.

The risk of miscarriage and premature birth is also higher in women with Down's syndrome.

^^ Back to top

Health Conditions

Some children with Down's syndrome have very few health problems as a result of their condition. Others will need extra medical care and attention.

Your child will usually need to be checked by a paediatrician more often than other children to help them stay in good health.

If you have any concerns about your child's health, talk to your GP, health visitor or paediatrician.

Heart conditions

Around half of children with Down's syndrome are born with a congenital heart defect.

The most common defect to affect children with Down's is a septal defect.

This is a hole inside one of the walls that separate the 4 chambers of the heart, often referred to as a "hole in the heart".

If your baby is diagnosed with Down's syndrome, their heart will be carefully checked to spot any problems as soon as possible.

They may need surgery to repair the heart if a problem is found.

Gut problems

People with Down's syndrome are more likely to have some sort of problem with their digestive system.

Constipation, diarrhoea and indigestion are all more common.

More serious problems may include:

  • small bowel obstruction – which stops food passing from the stomach into the large bowel
  • coeliac disease – a condition where a person has an adverse reaction to gluten
  • reflux – bringing up milk during or shortly after feeding
  • imperforate anus – where a baby is born without an anal opening
  • Hirschsprung's disease – which causes poo to become stuck in the bowels

Hearing problems

People with Down's syndrome are more likely to have problems with their hearing. This is often temporary, but it can sometimes be permanent.

A build-up of fluid in the middle ear (glue ear) is a common cause of temporary hearing problems in children with Down's syndrome.

If your child has glue ear, they'll usually be referred to an ear, nose and throat (ENT) specialist.

Vision problems

People with Down's syndrome often need to wear glasses to correct their vision.

Thyroid problems

Around 1 in 10 people with Down's syndrome have problems with their thyroid gland.

This is responsible for controlling your metabolism, the rate at which your body uses up energy.

Most people with Down's syndrome who have a problem with their thyroid have hypothyroidism, which means their thyroid gland is underactive.

Symptoms of an underactive thyroid gland can include:

  • lack of energy
  • weight gain
  • slow physical and mental reactions

Hypothyroidism is usually picked up by blood tests.

It can usually be treated with medication to replace the lack of thyroid hormone in the body.


People with Down's syndrome are more likely to develop infections, such as the lung infection pneumonia.

This is because the body's natural defence against infection (the immune system) has not developed properly.

As well as routine childhood vaccinations, your child may be offered extra vaccinations, such as the annual flu jab, to help protect them against infections.

If your child develops a bacterial infection, a course of antibiotics will usually be prescribed to treat it.


People with Down's syndrome tend to develop dementia at a younger age.

Possible signs of dementia include problems with short-term memory and understanding, confusion and disorientation.

^^ Back to top

The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website nhs.uk
Last Updated: 07/05/2021 14:38:22