What is NIPT and Why Is Everyone Talking About It: Mythbusting Non-Invasive Prenatal Testing

06/06/2016 13:19 | Updated 06 June 2016

In January of this year, the National Screening Committee recommended a period of review to assess whether non-invasive prenatal testing (NIPT) for Down's Syndrome and other serious genetic diseases be offered to all high risk women on the NHS. This recommendation has sparked widespread debate. Naturally, with any new tests, there can be confusion.

Lately, people have been asking me a lot of questions about what this recommendation means for them. Here, I want to help to answer those questions and talk you through the facts about NIPT. At my clinic, the test we offer is called the IONA® test as we believe it is a highly effective screening test and is the first to be CE marked for quality. Mums-to-be should speak to their midwife and obstetricians about the options available to them.

First of all, how does NIPT work?

From 10 weeks gestation a small blood sample can be taken from the mother's arm and sent to a local laboratory for analysis, using an NIPT test such as the IONA® test. During pregnancy, the placenta leaks DNA from the baby into the mothers bloodstream. As a result, the mother's blood sample contains a mixture of placental and maternal DNA. This can be extracted from the mother's blood sample and genetic testing performed on the small amount of DNA present.

The mum's blood sample is sent to the IONA® lab, based in Manchester, where it is analysed for Down's Syndrome and two other serious genetic diseases, Edwards' and Patau's Syndromes. Edwards' and Patau's syndrome are much rarer than Down's syndrome, but are very serious and many affected babies die before or soon after birth. NIPT is completely safe for the baby and avoids the pain, stress and the risk of miscarriage from a more invasive procedure such as amniocentesis, where a needle is inserted into the womb and amniotic fluid removed through mum's tummy. For an expectant mum, any risk is just too high, so it's fantastic we have been able to employ NIPT testing and reduce mum's stress. Also, the results come back in just under a week, which is so important during a very anxious time.

Why did the NSC recommend that NIPT be introduced?

Traditionally mothers are offered a combined test: this is an ultrasound scan combined with a blood test. This is less accurate than NIPT, only detecting about 85% of babies with Down's Syndrome. The IONA® test is also better at avoiding false positives - this is when your test result says your baby is at a high risk of having Down's syndrome, but is actually healthy. Ordinarily, women who get a high risk on their combined test will be offered a needle test. The NSC have recommended that NIPT is offered before invasive testing such as amniocentesis. Using a more accurate test means that fewer pregnant women will undergo unnecessary invasive follow-up procedures, which is big step in the right direction for mums-to-be.

Is this a way of reducing the number of babies born with Down's Syndrome?

This is not a new test to find Down's, rather it is an improvement on the current test. It gives expectant parents more accurate screening results to enable them to make informed choices about their pregnancy and reduces the need for invasive procedures.

It is important for people to remember that all antenatal screening tests are optional, and not mandatory. The choice will, as ever, be down to the individual woman and whether it is right for them. Women who do not wish to have exploratory tests don't need to have NIPT. This recommendation is aimed at those women who would previously have had to go through amniocentesis or CVS, safely giving them a more accurate risk of Down's and other syndromes.

Many women choose to continue with their pregnancy following a positive test for Down's, but learning this information early gives them and their families time to prepare for the birth, and also allows doctors to make sure that the baby is looked after in the best possible way.

But surely making prenatal testing easier and simpler to access will mean an increase in terminations of babies with Down's Syndrome?

This is the crux of the concern that many Down's Syndrome campaigners have about NIPT, and is a valid and important question. Debates around screening carry a lot of emotion for parents of children with Down's, and their voices and opinions are important and deserve be heard.

However, in my own practice, I have not seen a rise in terminations since introducing NIPT. A study by Professor Kypros Nicolaides of the Fetal Medicine Foundation looked at over 15,000 pregnancies and found no increase in terminations since the introduction of NIPT. In my experience, women who don't want testing will continue not to have it, and those who want a test are always relieved to be offered an option which is safer, better, faster and carries no risk of miscarriage.

What happens if a mum-to-be gets a positive result?

All high risk results would need to be followed up with a further diagnostic test. No NIPT or screening test is ever 100% accurate due to natural human biology. Women will be supported throughout this time to make the decision that is right for them. The media and their peers may have strong opinions, but it is so important to remember that the decision is theirs, and theirs alone.

What are the advantages for the NHS, and health professionals?

Invasive procedures are costly to the NHS because they require additional time and a trained health professional to carry out. NIPT will result in a dramatic reduction in invasive tests thus saving the NHS and health trusts money, while providing better care to pregnant mums.

Will I need to pay for NIPT if I choose to have it?

If you are considered high risk, it could be subsidised. The IONA® test can be purchased from private clinics and some NHS hospitals, costing around £300. Many mums have told us this is money well spent for the added peace of mind; however we hope it will be fully available on the NHS soon.