What is Non-Invasive Prenatal Testing?

When you’re pregnant, your blood contains fragments of your baby’s DNA.


A non-invasive prenatal test (NIPT) is a new type of test that analyses this DNA in a sample of your blood to predict the chance of Down syndrome (trisomy 21), Edwards syndrome (trisomy 18) and Patau syndrome (trisomy 13). Collecting your blood sample for NIPT poses no threat to your baby.

What does NIPT screen for?

NIPT screens for Down syndrome (trisomy 21), Edwards syndrome (trisomy 18) and Patau syndrome (trisomy 13). They cause moderate to profound intellectual disability and are associated with major congenital malformations.

Sex chromosome abnormalities, such as Turner syndrome (45,X) and Klinefelter syndrome (47,XXY), can also be detected, but with reduced accuracy. Sex chromosome abnormalities are often clinically milder than other chromosomal abnormalities. Testing for sex chromosome abnormalities will also reveal the fetal gender.

What is different about NIPT?

In recent decades, screening for these chromosome abnormalities during pregnancy has been called “First Trimester Screening” (FTS). FTS and NIPT are very different types of tests, both in what they test and the accuracy of their results. However, together they offer you very important information about your developing baby.

First trimester screening combines the results of biochemical blood tests with the structural findings measured under ultrasound to predict the chance that your baby has a chromosomal or other structural abnormality.

NIPT is a genetic test that analyses your baby’s DNA fragments that are circulating in your blood stream to detect the three most common chromosomal abnormalities. By directly analysing your baby’s DNA, NIPT results have been shown to be more accurate and have fewer false-positives (i.e. abnormal result that is incorrect) than FTS in identifying Down syndrome cases.

How accurate is NIPT?

NIPT is more accurate than traditional first trimester screening and much less likely to give a false-positive result. That means there will be much less chance your doctor would recommend follow-up testing, such as amniocentesis.

Why the Harmony Prenatal Test?

Since NIPT first became available in early 2013, there have been changes to test methodologies and new evidence has emerged about test performance. We carefully reviewed the evidence regarding the accuracy and reliability of different forms of NIPT, and chose the Harmony Prenatal Test. We constantly review the medical literature on NIPT to ensure that we are providing you with a test that meets these high standards.

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