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Next Biosciences brings you TriScreen – an advanced genetic screening test done in the first trimester of pregnancy to detect chromosomal (genetic) defects in the unborn child, mainly trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome) and trisomy 13 (Patau syndrome).

Most babies are born perfectly healthy. However, as many as 1 in every 33 babies can be born with a birth defect, some of which are more severe than others. These birth defects are now well understood and prenatal blood (serum) and ultrasound screening tests are offered to pregnant mothers to detect these defects early on in the pregnancy.
With advancing technology, genetic prenatal tests are now available to analyse the unborn child’s genetic material and diagnose these birth defects more accurately.

What is the TriScreen test?

TriScreen is a non-invasive prenatal test (NIPT) that detects and analyses the baby’s DNA fragments in the mother’s blood.

When a women is pregnant, some of the baby’s DNA floats around freely in the mother’s blood stream. By taking a blood sample of the mother’s blood, we are able to detect and analyse the baby’s DNA and screen the pregnancy to see if there is any chance for Down syndrome, trisomy 18 or trisomy 13.

NIPT is performed from a single tube of the mother’s blood from 10 weeks of pregnancy. The results from NIPT are much more accurate than other traditional screening tests, and the detection rate for chromosomal defects is much higher.

NIPT is safe for the mother and the pregnancy, with no associated risk for miscarriage.

Because NIPT is a screening test, any abnormal results will have to be confirmed with CVS (chorionic villus sampling) or amniocentesis. Your doctor will advise which is most appropriate for you.


Cell-free DNA


What are chromosomes?

Chromosomes are thread-like structures in the nucleus of our cells that contain our DNA. We usually have 46 chromosomes arranged in 23 pairs. The first 22 pairs are numbered 1-22.

The last pair is the pair of sex chromosomes:

In men

In men, this last chromosome pair contains one X chromosome and one Y chromosome: XY.

In women

In women, this last chromosome pair contains two X chromosomes: XX.

It is essential that each of our cells contains the right number and configuration of chromosomes.


What are Chromosomal defects?

If there is an extra chromosome, or if parts of a chromosome are missing, chromosomal defects will arise, resulting in an affected child.
Extra or missing chromosomes are called “aneuploidies”. The most commonly seen aneuploidies are trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome) and trisomy 13 (Patau syndrome). All these syndromes can be accurately detected by TriScreen.

Trisomy 21 (Down Syndrome)

Trisomy 21 occurs when there are 3 copies of chromosome 21 instead of the usual 2 copies. It is typically associated with physical growth delays, characteristic facial features and intellectual disability. With better medical care and education, many Down syndrome children attend school, hold down jobs and overcome medical diseases associated with the syndrome.

Trisomy 18 (Edwards syndrome) and Trisomy 13 (Patau syndrome)

Trisomy 18 occurs when there are 3 copies of chromosome 18, and trisomy 13 occurs when there are 3 copies of chromosome 13.

Both disorders cause severe developmental issues and medical complications that are not compatible with life. Many pregnancies result in miscarriage, stillbirth or death in the newborn period.

“Life is a DNA software system.” Craig Venter


Who should have the test done?

If you are of advanced maternal age

Older than 35 years for singleton pregnancy and older than 32 for twin pregnancy.

If you have an abnormal or 'positive' serum screen

Ultrasound Concerns

If your Ultrasound shows concerns or abnormalities with foetal growth and/or development.

Family History

If you have a personal family history suggestive of trisomy 21, 18, 13 or other sex chromosome abnormalities.


TriScreen Process


Frequently Asked Questions

When can the test be done?

1 tube of the mother’s blood is drawn as early as 10 weeks of gestation.

When will I get the result?

You will receive the result within 10 working days of the blood being drawn

What do my TriScreen test results mean?

Your results will tell your doctor whether or not trisomies 21, 18, 13 or sex chromosome abnormalities (if ordered) are highly likely to be present in your pregnancy. In the case of a positive result, your healthcare provider will discuss what the results mean and what the next steps are.

Your test report will include 3 possible results for chromosomes 21, 18 and 13:

  1. No Aneuploidy detected – means the correct number of chromosomes was found
  2. Aneuploidy detected – means too many or too few copies of one of the chromosomes have been identified. This can mean a chromosomal abnormality exists and further diagnostic testing is required.
  3. Aneuploidy suspected – a borderline result, which occurs infrequently, and suggests there might be too many copies of chromosome present. Further diagnostic testing will be necessary.

If sex chromosome option is ordered, results will be reported as either No Aneuploidy detected or Aneuploidy detected.

What is the difference between a Screening test and a Diagnostic test?

Screening tests – screening tests can be a blood test, ultrasound or a combination of both to estimate the chance for certain birth defects. It is important to remember that a screening test does not provide a definitive answer about the condition that is being tested. If a screening test shows that there is a chance for a certain defect, a diagnostic test must be performed.

Diagnostic tests – diagnostic tests analyse DNA in detail from a sample of the pregnancy.

The two most common diagnostic tests available to pregnant women are chorionic villus sampling (usually called CVS) and amniocentesis.

CVS can be performed by a specialist between weeks 10–14 of pregnancy. In this procedure, a small sample of the placenta is removed either by inserting a small needle through the pregnant woman’s abdomen or by inserting a tube (called a catheter) through the cervix.

Amniocentesis can be performed in the second trimester of pregnancy or later. During amniocentesis, a small needle is inserted through a pregnant woman’s abdomen, and a small amount of the fluid is removed from the amniotic sac.

After either procedure, the sample is sent to a laboratory where the chromosomes are analysed.

Additional testing for other conditions can be performed on the sample from the CVS or amniocentesis, if indicated based on your specific family or medical history.

With both of these procedures, there is a risk of complications, including a small risk for miscarriage.

What is a false positive test result?

A false positive result indicates that the given condition is present when it is not, i.e. the test result will show that there is a chromosomal abnormality when in fact there is not.

What is a false negative test result?

A false negative results indicates that the given condition is not present when it actually is, i.e. a chromosomal abnormality does exist but it does not show on the test.

There is a small chance that false positive or false negative tests results can occur. This is normal in any screening test. If there is any doubt, a diagnostic test must be done to confirm or exclude a diagnosis (the presence of an abnormality).

Will I still need a chorionic villus sampling or amniocentesis?

If the TriScreen test comes back positive i.e. a defect has been reported in one of the chromosomes, you will need to have a diagnostic test like CVS or amniocentesis. Your doctor will advise which is most appropriate.

If the TriScreen test comes back negative i.e. all the chromosomes are normal, and the ultrasounds look normal, then you will not need a CVS or amniocentesis.

Can the test detect the sex of my baby?

The TriScreen test can test for the sex of the baby. This test is OPTIONAL. If you do not want to know the sex of the baby, you will not be told the outcome of this part of the test.

Sex chromosome testing can only be done in singleton pregnancies. It cannot be done in twin or triplet pregnancies.

What other genetic defects can TriScreen detect?

If your healthcare provider chooses, the TriScreen prenatal test can also be used to identify:

  • Sex chromosome abnormalities, such as Turner syndrome (only one X chromosome in a female) or Klinefelter syndrome (an extra X chromosome in a male). Other possible conditions are Triple X and Jacob’s syndrome (an extra Y chromosome in a male).
  • Additional aneuploidies such as trisomy 9 and trisomy 16
  • Microdeletion conditions which are caused by a small missing pieces of a chromosome material, such as:
    • 2 deletion syndrome (DiGeorge syndrome)
    • 1p36 deletion syndrome
    • Angelman syndrome
    • Prader-Willi syndrome
    • Wolf-Hirschhorn syndrome
    • Cri du Chat syndrome

The about expanded aneuploidy and microdeletion tests must be requested separately. If any abnormality is found, the test must be confirmed with a CVS or amniocentesis.

Does a normal TriScreen test mean that my baby is perfectly healthy?

The TriScreen test is a highly accurate advanced screening test. However, no test can guarantee a baby will have no medical issues. The TriScreen test only addresses aneuploidies of chromosome 21, 18, 13 and the sex chromosomes, if ordered. It does not test for, or report, all genetic and non-genetic problems that may occur in your unborn child. If the test result is No Aneuploidy Detected, indicating a negative result, it does not completely rule out all potential problems with chromosome 21, 18, 13 or all sex chromosome aneuploidies in your baby.

Genetic counselling before and after testing is recommended.

Results of Aneuploidy Detected or Aneuploidy Suspected are considered positive and women who receive such results should be offered diagnostic tests, such as CVS or amniocentesis, for confirmation.