SAFE tests vs NIPT vs Harmony

[CatintheFireplace]

Could someone please explain the difference? Do they test for different things? Have different levels of accuracy? And when can they've done? I have googled, honest, but it's very confusing with different providers pushing different things

Thanks all.

@FoxtrotSkarloey is right, and there are also lots of other “brands” of NIPT available.

I think the accuracy for the main trisomies (Down’s, Edward’s and Patau’s) must be pretty similar across the board. Some test for additional syndromes, but I understand that these results aren’t as accurate as for the main trisomies.

@nanmumandmidwife is very knowledgable about this and will hopefully be able to add her insight.

Read the info here
www.arc-uk.org/tests-explained/non-invasive-prenatal-testing-nipt

As others have said there are various brands of NIPT, they are all quite similar though. I personally had Harmony as that was the nearest to me. I had mine at what I thought was 10+3 but they thought 10+2 based on measurements. It had to be when at least 10 weeks to collect enough fetal DNA to test.
I think some tests don’t offer sex, Harmony does though.

Thanks all, that makes sense. That link is really helpful.

NIPT means “ non invasive prenatal test”. Generally that is used as a generic term for the sophisticated screening test for Downs, Edwards and Patau’s syndromes (trisomy 21,18 and 13). They use the same basic science of fetal DNA fragments being founded in maternal blood, but there are several ways of caputuring them.
Many people talk about Harmony as though it is the only NIPT, in the same way we might say Hoover to refer to a vacuum cleaner.
Harmony have just spent the most on advertising!
Many, many other branded tests are available, including SAFE, NIFTY, Panorama etc In principle they all do the same, assessing the chance of fetal trisomy by looking at little bits of fetal DNA in mum’s blood.
Important issues to consider:
1.this is always a screening test - it is not a certain diagnosis. The advertising standards authority recently won cases against several providers.

1. Internationally NIPT is only considered valid & reliable for tri 21, q18 and 13. Some tests offer results for other conspditions, but in many cases you would be as well to guesstimate the chance
2. It is more reliable for Downs than for Edwards or Pataus.
3. False positives are more likely than false negatives.
4. Where is the test processed? The SAFE test is done in an NHS accredited lab (at St George’s) and clinicians have ready access to experts in the case of unusual results.
5. Who does the test? Do they have expert knowledge to discuss with you what tests are appropriate in your specific situation ? What back up do they offer or have themselves if things get complicated?
6. Some test labs will take samples from anyone with no quality control, or assessment of the ability to give appropriate information/counselling/ support to clients in the case of a concerning result
7. How are results given to you? Whilst working in the NHS I met far too many people who had test x done and were then given a result of concern late on a Friday evening by email with advice to “contact your NHS provider to discuss”.

Just a little food for thought... Very happy to discuss further if anyone is interested

Remember they only look at the trisomies. There are many other genetic chromosomal conditions available.

Thank you so much @Nanmumandmidwife! One question - how do these tests differ from the ones you get automatically on the NHS? Is it worth taking them before the NHS one? Or only if the NHS one comes up with a higher risk than you're comfortable with? I'm 37 so potentially at a higher risk I guess, but do t want to throw money away unnecessarily.. thank you again.

The routine test offered to everyone in the NHS is the combined test. That is a statistical assessment of chance, looking at how “average” your results are for the nuchal translucency measurement (back of baby’s neck) and two hormones in your blood. That is computed with your agape, assuming that chance increases with maternal age). You get a pen assessment of chance.
The problem is that we are not all average! It may be quite normal for you to have higher or lower hormone levels than average. No-one knows what is ideal for you.
These tests will pick up about 70-75% of affected babies. This means that a significant number of affected babies are not identified. However, in doing this a great many women are worried for no reason.
NIPT ignores a averages and looks at fetal DNA.
My usual advice would be to have the routine first trimester scan & combined test & the discuss with someone who really knows what they are talking about and is keen to understand your thoughts, feelings and priorities.
I usually have a long phone call with people and the. A hour or so face to face before doing an NIPT. I want to be sure that it is a suitable test, technically and emotionally for you. I want to be sure that you understand the pros & cons. I feel it is important to at least in principle have thought a bit about “what if”.
A lot depends what you might do with the information that such tests provide.

It was totally worth the money for us (£399), I conceived at 40, DH was 45 (41 and 46 at birth). We didn’t want to continue the pregnancy if any of the trisomies were found and the risk score from the combined test would definitely have been higher due to the age factor. I wanted to know early if we needed to terminate.
Obviously we still had some concerns at 12 and 20 week scans of other issues being found but we didn’t need to consider amnio or CVS so it was worth it for us. Our results were 1/10000 for everything tested and scans were clear. The combined test on the NHS would never have given me 1/10000 due to age so we’d have had unnecessary worry, and we were already terrified of miscarriage.
The added bonus was the early scan as we knew pregnancy looked viable and dates were accurate.
I’d not hesitate to do it again, our results took 5 working days to arrive by email. Our clinic phones people first though if a high risk result is found.
Because we live rurally there was only one clinic within an hour of us so we had no choice of which test to use unless we spent even more money travelling. I think limited choice is sometimes helpful!

Our hospital offered NIPT at a cheaper price (£250) but only after 12 week scan (as they don’t include a scan for NIPT, bloods only), which for me was too late as I’d have been nearly 14 weeks rather than 11 when results known, and for bad news that difference mattered.

Thanks @Nanmumandmidwife, that's really helpful. When you say These tests will pick up about 70-75% of affected babies does that mean that the NHS tests miss 25-30% of babies affected and wrongly classify them as "low risk" - that's quite a worrying statistic.

Thanks @Megan2018. Interesting to hear you can have them early, as I doubt we'll have out "12 week scan" before 13 weeks at least, so unlikely to get results before 14 weeks I guess which is quite late..

I'm having my tests done at 10 weeks.

Info here about the combined test results & reliability. www.qmul.ac.uk/wolfson/services/antenatal-screening/screening-tests/combined-test/#performance
To identify more the threshold (increased/low chance) would have to be changed which would mean that more people were given an false positive (worried unnecessarily)
Remember that signs are also looked for on scan & some more affected babies are identified that way, the vast majority of babies with Edwards or Pataus can be identified by scan appearances

Thank you!

@CatintheFireplace I didn't have a nipt test my first pregnancy- 38 conceived, 39 gave birth. NHS results came back 1 in 6000 and 1 in 7000 for other trisonomies. I was happy with that result. Second pregnancy conceived at 39 and 13 week scan found fluid round baby, decided not to have test as would come back high risk, opted for tfmr when second scab with specialist indicated baby would die anyway. Resulta later found it was t21.

This time around.. Conceived at 40 and will be 41 when give birth I opted for prenatal safe test which comes back really quickly (tested Tues, resukts Fri) , is 99.9 accurate, but only comes back either low risk or high risk--no numbers.

If I was your age I would probably have the nhs test first and then decide based on how low/high risk you are. I know lots of people who have been high risk on NHS and then low risk on nipt.