Cell free Fetal DNA (NIPT)

This test for Down syndrome and other chromosomal problems is relatively new and is currently available. The lab can extract free Fetal DNA from the pregnant woman’s blood and can run a test for extra fragments of chromosomes 21, 18 and 13. The test can also detect some of the sex chromosome abnormalities and if you wish foetal gender can be checked as well. This test can be done from 10 weeks onwards. The test can be done for twin pregnancies as well.

The accuracy of this test is over 99% for Down Syndrome. It is not diagnostic but is regarded as an advanced screening test. If a result from this test comes back as high risk, it must be confirmed by an invasive test, your health provider will discuss more with you about it if it is indicated.

NIPT can be a primary screening test for Down syndrome and other chromosomal abnormalities following counselling or can be recommended following high risk result on NT screening. A first trimester ultrasound examination is still recommended to confirm gestational age, detect presence of twins or vanishing twin and identifiable structural anomalies in early pregnancy. The turnaround time for NIPT result at this stage is 10 working days. Currently, this test is still expensive and has no associated Medicare rebate.

A detailed morphology at 19 – 20 weeks is recommended if NIPT results are low risk.