Non-invasive prenatal testing or NIPT is a screening test designed to determine the likelihood of a child developing certain genetic abnormalities. During pregnancy a child’s DNA mixes with the mother’s in her bloodstream, allowing doctors to perform a simple blood test to examine the genetic material and find particular issues early.
Non-invasive prenatal testing is a highly sensitive prenatal screening test that can help mothers understand the risk of their child developing certain genetic abnormalities during pregnancy. The test is done in the first trimester and screens for:
- Downs syndrome: a genetic disorder caused by a partial or complete copy of chromosome 21, which is associated with developmental delays and intellectual disability.
- Edwards syndrome: a genetic disorder caused by a partial or complete copy of chromosome 18, which causes severe developmental delays that are often fatal before birth or within the first year of life.
- Patau syndrome: a genetic disorder caused by a partial or complete copy of chromosome 13, which causes severe issues with development that are often fatal within the first week of life.
- Turner syndrome: a genetic disorder caused by a female born with only one X chromosome, which is associated with short stature, delayed puberty, infertility and particular learning difficulties.
While all of these genetic abnormalities are very rare, screening for them allows the mother and their families to properly prepare for all eventualities and make informed medical decisions based on the findings of the tests.
Who should consider non-invasive prenatal testing?
Non-invasive prenatal testing is not a standard test in the first trimester, and is only offered in particular specialist clinics, however, it can be an extremely useful test for mothers who:
- Are over 35 years of age, which increases the chance of their child having a genetic abnormality.
- Had a past pregnancy with a genetic abnormality.
- Had abnormal test results from their first trimester ultrasound or other tests and screenings.
Non-invasive prenatal testing has had such an impact on prenatal screening because of its major benefits:
- It is 99% accurate. NIPT is highly accurate at screening for Downs, Edwards, Patau and Turner syndrome, which makes it more effective than the regular ultrasound at detecting potential abnormalities.
- It is non-invasive. Unlike some tests such chorionic villus sampling (CVS) NIPT is non-invasive, which means that it poses no risk of miscarriage.
- It can be done as soon as 10 weeks. Because the test is available from 10 weeks, it can help parents start preparing earlier and with better certainty.
What are some considerations you should be aware of?
Non-invasive prenatal testing is highly accurate, however, it is still a screening rather than diagnostic test. This means that while it can help assess the likelihood of a baby being affected, it can not give parents a definitive answer, which will require a diagnostic test like CVS. It can however allow mothers make better informed decisions about how to prepare and whether to take a more invasive test to get a definitive diagnosis.