Non-Invasive Prenatal Testing (NIPT)

What is non-invasive prenatal testing (NIPT)?

NIPT is a test that uses a sample of the mother’s blood during pregnancy to determine if the developing baby
has certain chromosome conditions that can affect health and development.

During pregnancy, some of the DNA from the baby (fetal DNA) crosses in to the mother’s bloodstream. This
DNA carries the baby’s genetic information. It is this fetal DNA that is tested and analysed during NIPT to check
for certain chromosome conditions.

What does the NIPT test for?

Chromosomes are the packages which contain the body’s DNA. Problems in the body’s development or
function can occur when there is too much or too little chromosome material.

The most commonly known chromosome condition in newborn babies is Down syndrome (also known as
Trisomy 21) which is caused by having an extra copy of chromosome number 21 in each cell of the body.

NIPT tests for conditions in the baby where an entire extra copy of a chromosome is present or missing. Most
NIPT tests will test for common conditions including Down syndrome (Trisomy 21), Edward syndrome (Trisomy
18), Patau syndrome (Trisomy 13) and certain sex chromosome problems. Women who are considering NIPT
should be aware that not all tests look for the same chromosomal conditions and it is important to talk to your
health care provider about the specific conditions the baby is being tested for.

Who might want to have NIPT?

The test might be useful for women in the following situation/s:

.
An ultrasound indicates a problem with the baby’s growth and/or development
.
A screening test during the pregnancy has indicated that the baby is at increased risk of having a
chromosome condition
.
A previous pregnancy has been affected by a chromosome condition
.
Older mothers (aged 35 years or more at the date of delivery) who are at a higher risk of having a baby with
a chromosome condition


How accurate is NIPT?

NIPT is highly accurate for the chromosome conditions that it tests for however the accuracy is not 100%. There
are also differences in the accuracy, depending on the chromosome condition. For example, the result for Down
syndrome may be more accurate than for the other chromosomal conditions tested for. There is also the
possibility that following testing, no results are given. This may be due to there being too little fetal DNA in the
mother’s blood or difficulty identifying fetal DNA in the mother’s blood.


Important points

.
A screening test during early pregnancy to detect Down syndrome and other chromosome conditions
.
The test is safe and does not pose any risk to mother or baby
.
Currently only offered through specialist centres at a cost to the patient – no Medicare rebate is available
for this test.
.
NIPT, like all prenatal tests, is optional
.
The accuracy of NIPT tests is high though not 100%
.
A definite diagnosis of a chromosome condition in the baby can only be made following an invasive prenatal
diagnosis test like CVS or amniocentesis.

 


 Non-Invasive Prenatal Testing (NIPT) Fact Sheet 17D

 
www.genetics.edu.au 30/07/2013


New South Wales Health
Does a normal NIPT mean that the baby is healthy?

No test can guarantee that a baby will be healthy at birth. NIPT looks for a number of chromosome conditions
including Down syndrome. 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.

The health professional providing information about NIPT is the best person to ask about what will and won’t be
tested for.

How early in pregnancy can NIPT be used?

The test can be used as early as 10 weeks of pregnancy though this may differ between companies offering the
test.

What if the result of the NIPT shows that the baby might have a problem?

If the NIPT result shows that the baby has a chromosome condition, information about the condition will be pro-
vided. It is likely that your health care provider will discuss confirming any concerning test results using invasive
diagnostic testing procedures such as chorionic villus sampling (CVS) or amniocentesis.

Can NIPT harm me or my baby?

The test is conducted on a sample of the mother’s blood. The mother may experience some discomfort or dis-
tress when undergoing a blood test. There is no risk to the baby.

Who can I talk to order this test?

This test is usually only offered by specialist medical practitioners.

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