Everything you need to know about the NIP test (NIPT)

Also read: What tests are necessary during a normal pregnancy?

What does the NIPT do?

The NIPT can test the entire genetic material. It is therefore possible that other genetic defects will come to light than just chromosomal abnormalities such as Down syndrome. However, that defect must be large enough to be visible in the NIPT. A normal NIPT does not rule out the presence of a genetic error.

The following chromosomal abnormalities are examined:

• Down syndrome (trisomy 21)
• Edwards syndrome (trisomy 18)
• Patau syndrome (trisomy 13)
• Trisomy of a chromosome other than 13, 18, or 21 (very rare)

Trisomy 13 and 18 are rather rare chromosomal abnormalities that are associated with severe intellectual disabilities and physical abnormalities. Most children with trisomy 13 or 18 die shortly before or after birth.

Also read: Down syndrome (trisomy 21)

Is the NIPT mandatory?

The NIPT gives you a lot of information about your unborn baby and is without any risk. That is why you may feel 'obliged' to have the NIPT performed, for example because the gynaecologist or your family suggests it. However, the NIPT is not obligatory, just like all other screening tests. If you do not want any tests or NIPT, you can indicate this to your gynaecologist or GP.

Before you decide to take a test, you should think carefully about the following:

• The NIPT does not provide complete certainty about Down syndrome.
• If the NIPT is abnormal, an amniocentesis is the (logical) next step.
• What would you do if the result was abnormal? What would you do if it turned out that your child had a congenital defect?

Taking these things into consideration will help you and your partner decide what is right for you.

Also read: 22q11 deletion syndrome: most common syndrome after Down

Advantages of the NIPT

Safety
With NIPT there is no risk of miscarriage. Unlike amniocentesis or chorionic villus sampling, NIPT is a non-invasive test. Only a blood sample from the mother is needed.

Reliability
The NIPT is more reliable than the classic combination test. NIPT therefore allows more babies with trisomy 21 to be detected and the number of invasive tests (which do entail a risk of miscarriage) to be reduced.
The NIPT has a sensitivity of more than 99 percent. In less than 1 percent the NIPT is false positive.

Also read: Testimony: Eline had a child with Down syndrome

When is a NIPT recommended?

A NIPT is recommended in the following circumstances:

• if you are 36 years or older, because you then have an increased risk of having a baby with trisomy 21
• if you have had a previous pregnancy with trisomy 21, 18 or 13 or if trisomy runs in the family

Are you considering a NIPT for another reason, for example because of known genetic abnormalities in the family? Discuss this with your doctor. Other genetic conditions require other tests.

Also read: Ultrasound: What is the difference between a 3D ultrasound and a 4D ultrasound, and are they safe?

What happens if the NIPT gives a positive result?

If the NIPT is positive, then there is a high chance of an abnormality. This must always be confirmed with an invasive test (chorionic villus sampling or amniocentesis). In this test, the baby's genetic material is examined directly. Only after this additional test is there complete certainty as to whether or not the baby has trisomy 21 (or another abnormality). Other frequently occurring genetic abnormalities are also examined.

Also read: Non-invasive prenatal test (NIPT) detects blood cancers

Sources:
www.fara.be
www.uzleuven.be/nl/nipt
www.uzgent.be
www.uza.be
http://www.brusselsgenetics.be