Once you’re pregnant, life is suddenly a whirlwind of excitement and anxiety and queasiness – and tests. All sorts of tests for all sorts of things, it seems. And one of the newest antenatal tests that people are talking about most often is Non Invasive Prenatal Testing, or NIPT, for short.
What does NIPT test for?
NIPT, also known as cfDNA screening, is a blood test that can tell you if your baby has a high chance of having conditions such as Down’s syndrome, Edwards’ syndrome and Patau’s syndrome.
It can be done from about the 10th week of pregnancy, and offers a more accurate result than the routine ‘combined screening’ test you are offered on the NHS around the time of your 1st booking-in appointment.
But it still can’t give you a definite yes/no answer.
What is the benefit of NIPT then?
Currently, if you have the routine combined screening test and it indicates a high chance of Down’s syndrome, Edwards’ syndrome and Patau’s syndrome, you are then offered an invasive test – either an amniocentesis or chorionic villus sampling (CVS) – where doctors insert a needle into your bump to remove cells that can be analysed to give you a 98% to 99% definite yes/no answer.
As these tests are invasive, they carry a (small) risk of miscarriage.
But now, because NIPT is so much more accurate than the combined screening test, it’s a much safer next step – a low-risk NIPT result means you don’t then need to risk the amniocentesis or CVS.
“NIPT for Down’s syndrome is not diagnostic, like an amniocentesis or CVS, but large-scale studies show that the test has a detection rate of over 99%,” says Jane Fisher, director of the charity Antenatal Results and Choices (ARC). “It is currently a very sensitive screening test. It will still only give you a risk rating, but it’ll be a much more accurate one [than the combined screening test].”
Is NIPT available on the NHS?
Not to everyone just yet but it looks like it will be soon. The UK National Screening Committee recommended in January 2016 that it should be made available nationwide, so NIPT should be rolled out throughout the UK in 2018. And it is actually already available in some hospitals – including all NHS hospitals in Wales.
The plan is to offer NIPT, as a secondary test, to any pregnant woman whose combined screening test suggests a 1 in 150 chance (or more) of Down’s syndrome, Edwards’ or Patau’s.
“Then, if the NIPT result says your baby is very likely to be affected with one of the conditions,” says Jane, “you would still need an amnio or CVS to get that [almost] definite yes/no answer.
“But offering NIPT testing means many women will get a NIPT result telling them their baby is very unlikely to be affected after all – so that means they can avoid having a CVS or an amniocentesis.”
So, NIPT won’t replace invasive testing like amnios and CVS. But it will, in ever so many cases, rule out the need to have them.
This is what happened to Teetee, who posts on our Chat forum and found that her hospital, St George’s in London, is one of those already offering NIPT.
“After my combined screening, I was put at high risk for Down’s: 1 In 25,” she says. “I already have 2 kids, so was totally distraught. I had [the NIPT] blood test. It came back all clear.”
To put all this into some kind of context, the UK National Screening Committee predicts that, by offering NIPT as this 2nd stage of testing, the number of amnio and CVS procedures done every year will drop from 7,910 to 1,434.
Can I get NIPT privately?
Yes. There are lots of places offering NIPT privately – to women who are 10 weeks pregnant or more. And, to be honest, the choices and options and prices can all seem rather bewildering.
“There are many commercially available tests,” says Professor Lyn Chitty, who led the NHS NIPT trials. “They all have slightly different characteristics and report different things. I do therefore think that women should be aware of which test is being used, and what exactly it is screening for.”
Some privately offered NIPTs, for example, include screening for many more conditions than just Down’s syndrome, Edwards’ syndrome and Patau’s syndrome – and some of those results may not come with such a high degree of accuracy.
“The NIPT result for Down’s syndrome is very accurate indeed but the testing is not so well validated for other much rarer conditions,” explains ARC’s Jane Fisher.
“We would advise you to think very carefully before agreeing to be tested for other conditions. The evidence is not so clear on how good NIPT is for these and sometimes you might be given information that leads to great uncertainty. We are also concerned about private providers having the expertise to deliver complicated genetic information.”
In other words, it’s important to do your research (check the company’s website for their published data on test performance) and work out what you actually want to be tested for before you book a NIPT privately.
Perhaps the most well-known privately offered NIPT is Harmony, which providers such as Ultrasound Direct and Babybond use. We can’t recommend any particular NIPTs but others we have heard of include The NIFTY test, The Maternit21 Plus Prenatal Test, Panorama Prenatal Screen, as well as Genesis Serenity Prenatal Test, Verifi Prenatal Test, and the IONA test.
What does a private NIPT cost?
Again, this can really vary – anything from about £350 to £900. ARC recommends that, if you’re quoted anything over about £500, you should get a really clear breakdown of what exactly it is that you are paying for.
What will the results tell me?
You will be given 1 of 3 possible results: positive (it’s highly likely your baby will have Down’s or another condition); negative (it’s highly unlikely your your baby will have Down’s or another condition), or inconclusive (usually becase there isn’t enough fetal DNA present in the sample to give an accurate result). If your result is inconclusive, you may be offered (or may want to book) another test. If your result is positive, you will need further tests to confirm a diagnosis.
Anything else I need to know about a private NIPT?
“You should always be scanned before you get a NIPT done,” says Jane. “This is to check gestation [how far along you are in your pregnancy] and that it is a single pregnancy.”
Some NIPT test packages will include the cost of a scan. If you’re having a NIPT before your NHS dating scan(usually done at about 12 weeks), you should make sure a scan is included; if you’re having a NIPT after your dating scan, you may not feel the need to pay for another one.
You should also make sure you find out:
- How long you’ll wait for the results. The average wait is between 3 and 10 working days.
- How you’ll be told the results. Some providers send them on by phone or email but others will ask you back in for a 2nd appointment to get the results in person.
- How the results will be presented. Will you get a copy of the lab report? Will someone be able to talk you through it? Will you be offered a 2nd test if the results are inconclusive?
- What happens if you get a ‘positive’ result. Does the clinic follow through in any way: helping you access NHS services for further tests and advice, for example? Or do you have to sort all that out yourself?
Will a private NIPT tell me the sex of my baby?
Yes, if you want to, you should be able to find out if your baby’s going to be a boy or a girl. For some people, this is one of the main attractions of a NIPT: because it can be done as early as 10 weeks into pregnancy, you can find out your baby’s sex much earlier than you would if you waited to see what showed up on the NHS 20-week scan (when most people find out whether they’re having a boy or a girl) or a private gender scan (not usually offered till you’re about 16 weeks).
So, is it worth paying for a NIPT?
There really is no right or wrong answer here and, of course, a lot will depend on whether or not you can afford it.
It’s certainly something to consider seriously if you live in an area where NIPT has not yet been rolled out on the NHS, and your combined screening result indicates a high chance. You may prefer to pay for a NIPT before proceeding straight to an invasive amnio or CVS, as the NIPT may show you’re actually not a high risk after all.
You may also want to go for a private NIPT from the beginning, if money isn’t an issue and it’s important to you to have testing done at the earliest opportunity and/or you’re desperate to know if you’re having a boy or a girl.
“Waiting for tests on the NHS can feel like a long time for some people,” says Jane. “NIPT can be done from 10 weeks so that means you will get a result early on in pregnancy which you may find reassuring.”
But it’s important to remember that a NIPT is much more than a ‘find out your baby’s sex’ test: you need to be prepared for the fact that you’ll find out about your baby’s chance of developing certain life-limiting conditions.
And it’s not necessarily the end of testing, either: if you do get a ‘positive’ result for Down’s, Edwards’ or Patau’s (or something much rarer), you will be advised to have further invasive tests – which may take a little while to organise.
“I think if we came back [from combined screening] with a risk of 1 in 100 or higher (even though 1 in 150 is considered high), we would opt to have a NIPT,” she says. “I would consider the cost well worth it for either peace of mind or to know [more clearly] what we’re faced with.
“However, my sister had a NIPT done [privately] at 10 weeks because her age [over 35] would almost automatically put her into high-risk category and she didn’t want to faff about.”
What is NIPD? Is it the same as NIPT?
No, NIPD is slightly different to NIPT. NIPD is short for Non Invasive Prenatal Diagnosis and it’s exactly the same sort of blood test as NIPT but, in this case, it provides a definite result for certain single gene disorders, including achondroplasia and thanatophoric dysplasia.
Also, because the test also definitely determine the baby’s sex, it is used in cases where either the mum-to-be or the dad-to-be is a carrier of an altered gene that, if the baby is male, can cause conditions such as Duchenne muscular dystrophy or haemophilia.
If you or your partner are already known to be a high-risk for conditions such as these, you will be offered NIPD on the NHS.