Screening for Down syndrome

Down syndrome is a genetic (chromosomal) condition that is present from conception. It happens when a baby has extra chromosome 21 material and may sometimes be called Trisomy 21. 

Down syndrome happens in families of all backgrounds. It is not caused by anything you or your partner did before or during pregnancy. It is a congenital condition (a baby is born with it). 

Learn more about Down syndrome. 

Screening tests check your baby’s chance of being born with a genetic (chromosomal) difference such as Down syndrome. It is your choice whether to have these tests. 

Screening may include ultrasound scans and blood tests. These tests are safe and do not harm you or your baby.

A screening test cannot diagnose Down syndrome. A ‘high risk’ result means it is more likely that there is a difference present.

Screening is offered to everyone during pregnancy, usually during the first trimester.

It is different from routine (normal) antenatal tests, and it is your choice whether to have these tests. 

Speak with your doctor or midwife to help you decide if screening for Down syndrome is right for you. Ask for information about each test so that you can make an informed decision.

If you’d like extra support to think through your options, you can use an online decision aid called YourChoice.  

It provides information about prenatal screening (and diagnostic tests) for genetic conditions and asks a few questions to help you work out what matters most to you.

YourChoice is designed to support decision making, but does not replace advice from a health professional.

There are 3 ways to screen for Down syndrome:

• combined first trimester screening
• non-invasive prenatal testing
• second trimester serum screening

Combined first trimester screening

This screening involves:

• a blood test between between 9 and week 13 of pregnancy
• a nuchal translucency scan between 11 weeks and 13 weeks and 6 days of pregnancy

The results are combined to estimate the chance of your baby having Down syndrome. 

Non-invasive prenatal testing (NIPT)

NIPT (non-invasive prenatal testing) involves a blood test after 10 weeks of pregnancy.

Second trimester serum screening

This screening involves a different series of blood tests during your second trimester.

A blood sample is taken between week 15 and week 20 of pregnancy.

Before your test, think about why you want to have it and how you might feel about the results. Talk with your partner, a friend, family member or your doctor so you can make an informed choice. 

You might also find it helpful to speak with a genetic counsellor, who can explain the different tests and what the results may mean for you. 

Some people find it helpful to access peer support and lived experience information alongside clinical advice. For example, Down Syndrome Australia (and state and territory Down syndrome organisations) can provide information and connect you with other parents and families who are happy to share what day to day life can look like.

Here are some questions you might want to ask your midwife or doctor:

• Why are you offering me this test?
• How accurate is the test? 
• What does the test involve?
• Do I need to do anything on the day of the test?
• When will I get the results?
• Who will contact me to give me the results?
• Do I need to do anything to care for myself after the test?
• What are my options if the results come back positive?

Read more about what to ask your doctor about tests and scans.

How much does screening for Down syndrome cost?

The combined first trimester blood test is covered by Medicare, but there may be costs for the ultrasound.

The NIPT blood test is not currently covered by Medicare and can be expensive. 

Ask your doctor to explain the costs of each test. 

Your doctor or midwife can explain your results and what they mean for you.

Screening tests estimate the chance that your baby may have Down syndrome. They do not give a definite diagnosis.
If your screening test shows a high chance that your baby may have Down syndrome, your doctor or midwife will talk with you about what happens next. You may be offered information about diagnostic tests, such as chorionic villus sampling (CVS) or amniocentesis. These tests can confirm whether your baby has Down syndrome.

You may also be offered genetic counselling to help you understand and talk through your options.

How is Down syndrome diagnosed?

Tests during pregnancy that can confirm whether your baby has Down syndrome include:

• chorionic villus sampling — which tests the placental tissue
• amniocentesis — which tests the amniotic fluid (the fluid around your baby)

After your baby is born, a blood test may be done to confirm Down syndrome.

• Down Syndrome Australia has information, support and resources for people living with Down syndrome and their families. Call their national phone number on 1300 881 935 and ask for your local organisation.
• YourChoice is a free online decision aid that can help you think through whether to have screening, and which tests might suit you. It asks a few questions, then provides a summary you can save to discuss with your doctor or midwife.
• Through the Unexpected – Through the Unexpected has information and support for parents who receive unexpected news about their baby during pregnancy.
• Prenatal Screening Awareness - Down Syndrome Queensland provides evidence based information to support informed choices about screening, diagnostic testing and pregnancy options. It also includes personal stories and support resources
• The Royal Australian and New Zealand College of Obstetricians and Gynaecologists provides more information on prenatal screening for chromosomal and genetic conditions.
• Children and Young People with Disability Australia (CYDA) provides information and support for children, young people living with disability and their families.
• Funding is available through the National Disability Insurance Scheme.
• The Human Genetics Society of Australasia has a ‘find a genetic counsellor’ service. 

Languages other than English

Down Syndrome Australia offers fact sheets and resources in languages other than English, as well as easy English versions. Topics include:

• advice for new parents with a baby living with Down syndrome
• a guide for expectant parents
• living independently
• an early years guide
• a video for parents of children living with Down syndrome talking about the diagnosis during pregnancy
• a video of parents of children living with Down syndrome talking about early intervention after their child’s diagnosis

Parent Line is a free telephone counselling and support service for parents and carers. It offers parenting support for families from culturally and linguistically diverse backgrounds.