The simple blood test that’s revolutionising prenatal screening

Expecting a baby is exciting, but it’s natural to worry about the health of your unborn child – particularly during the first trimester.

Non-invasive prenatal testing (NIPT) has made prenatal screening simpler and safer – and can be done as early as nine weeks into the pregnancy.

What Is NIPT?

“NIPT is a genetic screening test that any woman can choose to access during her pregnancy,” and it’s able to screen the unborn baby for a variety of genetic conditions,” says Liani Smit, a clinical geneticist at Mediclinic Precise. This simple blood test was initially developed to screen for Down syndrome but over time, NIPT’s ability to screen for other genetic conditions has improved. It can also determine the sex of the unborn baby.

“NIPT is currently the most accurate screening test for common chromosomal genetic conditions in a pregnancy,” says Smit. “A pregnant woman can discuss with her gynaecologist how broadly she would like to screen.”

However, she emphasises that NIPT is a screening test, as opposed to an invasive diagnostic test. “A screening test indicates either a high or low risk for certain conditions – it can never definitively diagnose a condition. So, if NIPT indicates a high risk, you’d want to do a diagnostic test, like an amniocentesis, to confirm the diagnosis.”

Benefits of NIPT

As the name suggests, NIPT is a non-invasive test with no risk to the unborn baby. The doctor simply takes a blood sample from the mother, as with any other blood test. The sample is sent to the laboratory, where DNA fragments of the pregnancy can be isolated in the mother’s blood and screened for genetic conditions. Results are usually available within two weeks.

In the event of twins, DNA from each twin can be identified and assessed for genetic conditions with the Panorama NIPT test offered by Mediclinic Precise.

If the NIPT screening indicates a low risk, it may limit the need for an invasive diagnostic test, such as amniocentesis. “Amniocentesis is still the gold standard for diagnosing genetic conditions, but it is invasive because it’s a needle test,” says Smit. “The procedure involves inserting a needle through the pregnant woman’s abdomen and womb and taking a sample of the amniotic fluid around the baby. There is some discomfort for the woman and a small risk of miscarriage. Because of that, some women may opt for NIPT instead.”

NIPT screening can be performed as early as nine weeks. “It’s a very early stage of the pregnancy – even before there may be concerns identified on an ultrasound,” says Smit, who says she elected to have NIPT screening during her own pregnancy. “This gives the expectant parents and their gynaecologist more time to decide on further pregnancy management.”

Limitations of NIPT

As reliable as NIPT is, it cannot screen for all genetic conditions. “If you have a genetic condition in your family, you can’t assume that NIPT will be able to screen for it,” says Smit. “That’s something you’d need to discuss with your gynaecologist. In such a case, it may be best to have a consultation with a medical geneticist or genetic counsellor who can recommend the most suitable genetic test based on your family history.”

Routine NIPT screening is not usually covered by medical aid, adds Smit, although you may be able to obtain preauthorisation if your pregnancy is considered high-risk. However, any pregnant woman can elect to have a self-funded NIPT screening and be empowered with the knowledge to make better, informed decisions about how to manage her pregnancy.

Find out more about Mediclinic Precise here.