RPAH RPAH
Medical Genomics / Clinical Genetics

Prenatal Genetic Counselling

Every pregnant women in New South Wales is offered tests during her pregnancy to monitor the health of the baby and to screen for signs of specific chromosome conditions. Prenatal screening tests can indicate those pregnancies at increased risk for certain chromosome conditions. If a prenatal screen result indicates an increased risk for a chromosome condition, a genetic counsellor can help support couples in making informed decisions about the option of additional tests available during pregnancy.

For some couples, specific diagnostic testing such as CVS or amniocentesis may be offered when there is an increased chance of having a baby with a known genetic condition.

For more information about prenatal screening tests and diagnostic tests, we recommend the NSW Health's Centre For Genetics Education Prenatal Testing Booklet.

 

What is Non-Invasive Prenatal Testing (NIPT)?

During pregnancy, some of the DNA from the baby (fetal DNA) crosses in to the mother’s blood stream. NIPT is a screening test that uses a sample of the mother’s blood during pregnancy to screen the developing baby's DNA for certain chromosome conditions that can affect health and development.

Every pregnant women in New South Wales is offered tests during her pregnancy to monitor the health of the baby and to screen for signs of specific chromosome conditions. Prenatal screening tests can indicate those pregnancies at increased risk for certain chromosome conditions. If a prenatal test indicates an increased risk for a chromosome condition, a genetic counsellor can help support couples in making informed decisions about the option of additional tests available during pregnancy.

NIPT tests for certain conditions in the baby where an entire extra copy of a chromosome is present or missing. Most NIPT tests screen for common conditions including Down syndrome (Trisomy 21), Edward syndrome (Trisomy 18), Patau syndrome (Trisomy 13) and certain sex chromosome problems. Very rarely, NIPT will identify a maternal chromosome condition, rather than a fetal chromosome condition.
NIPT does not analyse all of the baby’s chromosomes and DNA, therefore, will not rule out other chromosome conditions, genetic conditions and other health problems.

How accurate is NIPT?

NIPT is highly accurate for the chromosome conditions that it tests for; however the accuracy is not 100%. There is also the possibility that following testing, no results are given. This may be due to technical reasons and a recollection may be possible to obtain a result.

NIPT results are either reported as HIGH RISK or LOW RISK for each chromosome condition tested. We recommend that women consider diagnostic testing (called chorionic villus sampling/CVS or amniocentesis) if they receive a high risk result.

When should I do NIPT?

NIPT can be performed anytime from 10 weeks. We recommend waiting to make a decision about NIPT until after your First Trimester Screening results. First Trimester Screening uses ultrasound and a different blood test to screen for Down syndrome and other conditions. First Trimester Screening is performed between 11.5-14 weeks. Unlike NIPT, it involves an ultrasound assessment so other important information about the growth and health of the baby can be obtained.

How do I make an appointment?

To book an appointment for NIPT or First Trimester Screening, please phone the Foetal Maternal Unit on 9515 8258.
To discuss this information further with a genetic counsellor, please phone 9515 5080.
Detailed information regarding prenatal testing can be found through the Centre for Genetics Education Website.

What do I need to bring to my appointment?

When you attend your NIPT appointment, you need to bring a copy of the previous ultrasound reports (either your dating scan or First Trimester Screening result). The providers of NIPT are commercial and the testing is not covered by Medicare so you will also need a credit card to pay for the test.