Prenatal screening (genetic screening in pregnancy)

Genetic screening, or prenatal screening, is available to anyone who is pregnant. These tests estimate the chance that your baby has a genetic or chromosomal condition. Some tests may also identify signs linked to physical differences that can happen with certain genetic conditions.

There are different types of tests available. They differ in how accurate they are and what information they can give you. No single test checks for all conditions.

People have different reasons for choosing whether to have screening. For some, the information may help with planning or preparation. Others may prefer not to have this information.

Whatever you decide, support is available to help you understand your options and make the choice that feels right for you. Your doctor or midwife can explain why a test is recommended, what it involves, and its benefits, risks and other options. This will help you make an informed decision.

Combined first trimester screening

The combined first trimester screening (CFTS) looks at results from a few different tests to work out the chance of your baby having:

• Down syndrome (trisomy 21)
• Edwards syndrome (trisomy 18) (Opens in new tab)
• Patau syndrome (trisomy 13)

Doctors use many things to understand the chance that your baby may have these conditions, including:

• pregnancy blood test — to check levels of certain proteins in your blood
• nuchal translucency (NT) screening ultrasound — to measure the thickness of fluid behind your baby's neck
• if your baby's nasal bone can be seen on an ultrasound
• your age and weight
• how far along you are in your pregnancy

You can have this test between 12 weeks and 13 weeks and 6 days of pregnancy.

Second trimester serum screening

Second trimester serum screening is a blood test you have in pregnancy that helps you understand the chance of your baby having:

• Down syndrome (trisomy 21)
• Edwards syndrome (trisomy 18)
• neural tube defects (for example, spina bifida)

To check your baby’s chance of having these conditions, your doctor will look at:

• your blood test results
• your age and weight
• how far along you are in your pregnancy

This test may be offered between 15 and 17 weeks of pregnancy, but you can have it up to 20 weeks of pregnancy.

CFTS and non-invasive prenatal test (NIPT) have largely replaced second trimester screening.

Sometimes there is no out-of-pocket cost for second trimester screening. Check with your midwife or doctor about the costs of the test.

Non-invasive prenatal test

The non-invasive prenatal test (NIPT) uses a small sample of your blood. You can have this test after 10 weeks of pregnancy. From week 10, some of your baby's DNA from the placenta is found in your blood. The NIPT blood test examines this DNA.

NIPT estimates the chance your baby may have:

• Down syndrome (trisomy 21)
• Edwards syndrome (trisomy 18)
• Patau syndrome (trisomy 13)
• sex chromosome conditions
• microdeletion syndromes (where a small piece of a chromosome is missing)

NIPT can also identify your baby's sex.

NIPT is the most accurate screening test for detecting Down syndrome.

There are specialist clinics in Australia that offer this test. If you would like to have NIPT, ask your antenatal care provider where you can access the test.

NIPT is not covered by Medicare or your private health fund — ask your provider about out-of-pocket costs before you make an appointment.

Deciding about prenatal screening can be stressful. There is no single ‘right’ choice – different options may feel right for different people, depending on their values, beliefs, experiences and circumstances.

Before you decide about any prenatal screening tests, you can talk to your doctor, midwife or a genetic counsellor about:

• the advantages and disadvantages of each test
• what further tests you might need
• what the results might mean for you and your family
• how the information may (or may not) be useful to you

Genetic counselling can be helpful at any stage: before screening, after results or when considering further testing. Genetic counsellors give you information, help with decision-making and help you explore your options in the context of your own values.

If your prenatal screening test shows that your baby has a high chance of a genetic condition, you will be offered genetic counselling. Your counsellor will explain the facts to you and help you decide what to do next.

Diagnostic tests such as chorionic villus sampling (CVS) or amniocentesis may be offered. These diagnostic tests give you a definitive (yes or no) result.

You do not need to have these tests if you do not want to. You can talk to a trusted member of your healthcare team about your options — this may be your GP or midwife.

People consider many things when deciding about further testing, including:

• What you would do if the test shows there may be a genetic difference or condition?
• How do you feel about caring for a baby or raising a child with disability?
• What could it mean for your family?
• How might you feel during your pregnancy?
• Are there circumstances in which you would choose to end the pregnancy?

There is no expectation that you will make a particular choice. Support is available regardless of your decision.

The cost of prenatal screening depends on a few things, such as:

• if you are a public or private patient
• the type of test
• if your doctor thinks your baby has a high chance of having a chromosomal condition

You may be able to claim money back from Medicare for part of the cost of the blood test and ultrasound scan.

Medicare does not cover the NIPT. This test will cost you around $400 to $500.

Genetic (prenatal) screening involves screening tests you have during pregnancy to see if your baby may have an increased chance of having a genetic condition.

Carrier screening tests check if you and your reproductive partner have any changes (mutations) in your genes that increase the chance of your baby having a genetic condition. If you are planning a pregnancy, you may consider carrier testing.

Carrier screening is best done before pregnancy but can also be done during early pregnancy.

In either case, if a test shows that you have an increased chance of having a child with an inherited genetic difference, you can then choose to have diagnostic testing.

Medicare rebates are available for some types of genetic testing. These help people understand the chance of having a child with certain genetic differences, including cystic fibrosis, spinal muscular atrophy (Opens in new tab) or fragile X syndrome.

Sometimes, the result of your prenatal screening test can be upsetting. Remember that help and support are available to you.

You can find out more about screening tests by asking your doctor, midwife or a genetic counsellor.

• Learn more about genetic screening on The Royal Women's Hospital 'Genetic testing in pregnancy (Opens in new tab)' webpage. 
• YourChoice (Opens in new tab) 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 (Opens in new tab) has information and support for parents who receive unexpected news about their baby during pregnancy.
• Prenatal Screening (Opens in new tab) is a resource with 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 (Opens in new tab) provides more information on prenatal screening for chromosomal and genetic conditions.
• Murdoch Children’s Research Institute provides an information booklet (Opens in new tab) about prenatal screening, including about Down syndrome.
• Children and Young People with Disability Australia (CYDA) (Opens in new tab) has information and support for children and young people living with disability, and their families.
• Funding may be available through the National Disability Insurance Scheme (Opens in new tab).
• The Human Genetics Society of Australasia has a ‘find a genetic counsellor’ service. (Opens in new tab)

Languages other than English

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.

Information for Aboriginal and/or Torres Strait Islander peoples

• The National Centre for Indigenous Genomics (NCIG) can help you find genetic services across Australia.
• SMS4DeadlyDads is a free service for Aboriginal and/or Torres Strait Islander dads.
• If you, or someone you know, are feeling worried or no good, you can connect with 13YARN on 13 92 76 and talk with an Aboriginal and/or Torres Strait Islander crisis supporter.
• Ngangkita Ngartu, is an Aboriginal family birthing program at the Women’s and Children’s Hospital in South Australia.
• Moort Boodjari Mia (Family Pregnancy House) is a service in Western Australia for Aboriginal and/or Torres Strait Islander people who are pregnant and other people who are pregnant with an Aboriginal and/or Torres Strait Islander baby. Contact them on 08 9462 5092.