Trying to navigate early pregnancy can be a stressful time; there are lots to things to think about and consider, one of which is Non-Invasive Prenatal Testing (NIPT). You may be asking What is NIPT? Which NIPT test is best? Dr Alex Eskander, Consultant Gynaecologist here at The Gynae Centre, explains everything you need to know about NIPT.
What Is The NIPT Test For?
NIPT is an alternative, added screening for chromosomal abnormalities to give you peace of mind. NIPT screens your unborn baby for common genetic problems, including Down’s Syndrome (Trisomy 21), Edwards Syndrome (Trisomy 18), and Patau Syndrome (Trisomy 13). Down’s Syndrome is a congenital disease which arises from a chromosome defect. It can create severe learning difficulties, and is linked to vision and hearing issues, as well as heart problems.
Is The NIPT Test Accurate?
Traditionally a blood test, combined with the nuchal translucency scan at 12 weeks, is used to look at the nose bone and skin fold at the back of the baby’s neck in order to ascertain any abnormalities. This method is 92% accurate, but still leaves margin for error.
“NIPT testing offers a considerably higher degree of certainty – more than 99% accuracy when screening for Down’s Syndrome.
Although not 100% conclusive, it reduces the need for more invasive, higher risk testing,” explains Dr Eskander.
The only way to be certain of any chromosomal defects is to undergo an invasive procedure like Amniocentesis which withdraws some of the amniotic fluid that surrounds the baby, or Chorionic Villi Sampling (CVS) which takes a small amount of tissue from the placenta. Both of these tests are invasive, stressful, and involve risk of miscarriage. For mums-to-be, this is a nerve-wracking thought.
How Does The NIPT Test Work?
At around 10 weeks of pregnancy, some of the foetus’s DNA enters the mother’s bloodstream. NIPT is non-invasive, and involves taking a blood sample from the mother – zero risk to mum and baby – and analysing the sample for cell free foetal DNA. The test will determine the risk of genetic abnormalities; an imbalance of chromosomes shown in the blood sample may indicate a genetic condition.
NIPT is a fantastic advancement in the screening of genetic conditions but tests only look for a specific set of conditions, which don’t include some of the less common diseases like early preeclampsia, open spina bifida.
NIPT can also identify the sex of your baby early on if you don’t want to wait until the gender scan at around 18-21 weeks
Dr Eskander says: “It is particularly important for mothers who have a history of genetic abnormalities, or older mothers, to have NIPT as they are at higher risk of giving birth to a baby with chromosomal abnormalities. Being prepared is always advised and even if you are experiencing a normal pregnancy, NIPT can offer you peace of mind. The results of your NIPT test can help you decide whether to pursue further investigative testing, prepare to make adjustments to your life, and also enables you to come to the difficult decision of whether or not to terminate the pregnancy.”
Which NIPT Test Is Best?
There are currently two main NIPT tests available in the UK: Harmony Test and Panorama Test – both are offered at The Gynae Centre. All three have a high accuracy rate, are non-invasive, and are safe for mum and baby, and results take the same time to come through.
“Both NIPT tests offer a very high level of accuracy, but which you choose is a very personal choice. There are minor variations in the accuracy of the results, which we have outlined below so you can weigh up the differences and your options,” adds Dr Eskander.
|Harmony Test||Panorama Test|
|Down’s Syndrome (Trisomy 21)||Sensitivity||>99%||>99%|
|False positive rate||0.1%||0%|
|Edwards Syndrome (Trisomy 18)||Sensitivity||98%||>99%|
|False positive rate||0.1%||<0.1%|
|Patau’s Syndrome (Trisomy 13)||Sensitivity||80%||>99%|
|False positive rate||0.05%||0%|
|Turners Syndrome (Monosomy X)||Sensitivity||96.7%||91.7%|
|False positive rate||Unreported||<0.1%|
|Triploidy (optional)||Sensitivity||Unable to detect||>99%|
|False positive rate||>99%||0%|
|False positive rate||Unreported||0%|
(Table adapted from The Portland Hospital comparison)
The Gynae Centre is London’s finest private women’s healthcare clinic. If you would like to book an NIPT test with one of our consultants, simply call the clinic on 020 7580 8090 to book an appointment.