Women’s and Children’s Hospital • SA Maternal Serum Antenatal Screening Program

What is screening?

Most pregnancies end with the birth of a normal, healthy baby. A few do not.

Screening tests are used to detect people who have a higher chance of having a medical condition. In pregnancy, maternal serum screening is used to find out if you have a higher chance of having a baby affected by Down syndrome, Trisomy 18, a neural tube defect or some other rarer pregnancy pathologies.

Screening tests are not diagnostic. They cannot tell for certain if your baby is affected, they can only tell if your pregnancy is high risk or low risk.

If your pregnancy is high risk you will be offered a referral to a specialist and/or transfer of your care to the high risk team at an appropriate hospital.

If your pregnancy is low risk you do not need to do anything.

Do I have to get this test?

No. All testing is voluntary.

The SAMSAS Program supports women’s choice and the healthcare professionals who are supporting them in the management of their pregnancy.

Is it accurate?

Like any medical test, the tests used in screening are not perfect.

The test result may incorrectly show positive for unaffected babies (false positive), or negative for affected babies (false negative).

Current performance of screening done between 9 and 14 weeks shows it will detect >90% of babies with Down syndrome or Trisomy 18.

Current performance of screening done between 14 and 21 weeks shows it will detect >90% of babies with Down syndrome, Trisomy 18 or neural tube defects.

It is important to note that a low risk result does not guarantee an unaffected baby. A high risk result should be confirmed by further testing and seeking counselling is recommended.

What is the test?

There are 2 tests available:

First trimester screening requires a blood sample collected between 9 and 14 weeks and a detailed ultrasound performed between 11 and 14 weeks.

Second trimester screening requires a blood sample collected between 14 weeks and 20 weeks 6 days.

What are the risks?

Screening tests cannot harm you or your baby. They carry the same risks as having any blood sample collected.

Diagnostic testing (such as CVS or amniocentesis) carries a risk of miscarriage.

How do I access the test?

Discuss with your healthcare provider
They will fill out the Maternal Serum Screening request form
If you are between 9 weeks and 14 weeks they will also fill out an ultrasound request form
Have your blood collected between
1. 9 weeks and 14 weeks
2. or 14 weeks + 1 day and 20 weeks + 6 days
Have your ultrasound between 11 and 14 weeks gestation.

How long will the results take?

Once we have all the information we need, we can issue a report within 1-2 business days for first trimester screening and 2-3 business days for second trimester screening.

What are the costs?

Maternal serum screening is performed by SA Pathology and funded by Medicare, including for privately insured patients.

A referral laboratory may charge a collection or transport fee. Check with the laboratory providing this service.

A gap payment may be required for the ultrasound measurement. Check with the practice providing this service.

Frequently asked questions

No. As long as the blood is collected between 9 and 14 weeks gestation, we can combine the blood and scan information.

No, it’s not necessary. Just remember to bring the Maternal Serum Screening test request form with you to the collection centre.

No. Please eat as normal.

If you are in South Australia you can have your blood collected at any SA Pathology collection centre. You do not need to attend the Women’s and Children’s Hospital to have your blood collected.

If you are from Tasmania or the Northern Territory, please refer to the back of the Maternal Serum Screening request form, or ask your doctor.

At SAMSAS, we are sensitive to the fact that this can be a worrying time for you. As we cannot give results directly to patients, we encourage you to contact your healthcare provider and ask them to liaise directly with us.