Would you have NIPT after a high chance screening result?

[Orangeballoons]

Hoping for a handheld. I am pretty sure I have made up my mind but want to hear other people's experiences.

I am pregnant and my screening test has come back with high chance of downs. 1 in 21. I would never abort no matter what let's state that at the start. I also won't risk an amniocentisis.

However this is an IVF pregnancy and the blastocyst was PGTA tested so the chance of downs is probably fairly low.

I think that I don't want to do further testing but will accept a more in depth abnormalities scan.

If I do the NIPT test then whilst a negative would be reassuring a positive would still leave uncertainty and just be stressful.

Im so sorry for your stress 🤍

Just with you saying “a positive would still leave uncertainty and just be stressful” - would this feeling also be the case if you didnt do the test? If so then I would say go for it youve got nothing to lose - and you could gain reassurance from a negative

best of luck whatever you decide 🤍🤍🤍

I think atm as I know the 'high' result is just a statistical thing I am comfortable trusting the PGTA. I haven't got any readings outside of normal.

Another positive i think would add uncertainty. Unfortunately as I am not willing to risk the pregnancy I can't get absolute answers.

Even if I knew 100% my child would have downs I would keep the pregnancy and love my child. I would like to know as would help to prepare however...

Edited for typo

I would do the NIPT in these circumstances. It just helps you to have a bit more certainty in the likely outcome.

Like you, I wouldn't personally abort either way (although I appreciate nobody knows till they're in the situation) but I would want to prepare as best I can.

Xx

In your position, I think I would have the NIPT. Information feels valuable, and if the embryo was tested I'd be very confident for you the results will reassure and help you have fewer questions in your mind running up to the birth. If it's positive, you do have more uncertainty, but also may be in a better place to prepare for whatever the outcome is. Did they say which measurement(s) had likely put you into this risk category?
I was told the 20 week scan would not be able to screen for Downs Syndrome, other than if there is a detectable heart condition.

Whatever you choose to do, congratulations on your pregnancy!

I'm so sorry you're going through this.
Do you know what exactly was included in the PGTA? Obviously they can't test for every single genetic condition, but I would imagine most PGTA testing includes Downs Syndrome as standard. Do you know if it included any other trisomies or chromosomal anomalies as well?
Were there any concerns at your dating scan? Sometimes the combined screening can come back raised for Downs, Edwards or Pataus, but on further investigation it's actually a different trisomy.
Presumably you've already had a conversation with the antenatal screening team. They should talk to you about what would be available if you didn't go ahead with the NIPT - depending on how your hospital is resourced I would expect them to offer a scan with a fetal medicine consultant around 17 weeks and/or a fetal cardiac echo.
It's also worth knowing (perhaps you already do) that different NIPT providers screen for different trisomies. So they'll all screen for T21, 13 and 18 (Downs, Edwards and Pataus) but some will also screen for other trisomies that can trigger a raised T21/13/18 chance at the initial screening.
Sorry, I hope that doesn't add additional complications to your thought process - it's just some things to consider, and that I would have spoken to you about when I worked in antenatal screening.

The screening is based on a lot of things and not conclusive so often creates high chance results.
I would get the NIPT just so I could be prepared but it's completely up to you.

Also, it's worth looking at the whole clinical picture. Anecdotally, in my experience, a pregnancy with, say a 1 in 100 result, where there's also a raised nuchal thickness / absent nasal bone / fetal hydrops / a cardiac abnormality etc is much more likely to be an unwell baby (either with Downs or with a different chromosomal condition) than a pregnancy with, say a 1 in 20 result where all of the scans are unremarkable.

My age is a risk factor. I am 40. The nucleotransparancy reading was well within normal but not in the lowest risk category.

They checked for chromosomes. This included all of the trisomies and I have lower risk of the other conditions. The PGTA checked 21/13/18 as well.

I have been offered the 17 week scan with a fetal consultant and I think I will take that.

No other flags whatsoever. Nothing is outside normal ranges at all. It is just the statistical chance thing.

I would find this reassuring (with the caveat of course that I haven't seen your results, scans etc and don't know your medical history!). But this combined with your age and the PGTA definitely works in your favour, especially if all is well at the fetal medical scan.

Had a similar result and did NIPT and no regrets. The process was simple and I found the fetal medicine team were the loveliest people I had ever met.

May I ask how it went for you in terms of results?

I was 1 in 13 for Down Syndrome with my first baby (despite being 31 and having a normal NT - I think it was because I had high HCG). My trust does the NIPT automatically if you have a high chance screening - so I just got a letter in the post saying I was low chance, and didn’t read it too carefully. I only found out about the 1 in 13 chance result during this pregnancy (where the baby does have a heart condition, high NT and I was over 1 in 2 for the screening). Even though I wouldn’t consider termination no matter the results (and also have declined cvs/amnio because of the miscarriage risk) I would always want more information. A word of warning - I have been advised that the NIPT is very accurate for Down Syndrome, and accurate for Patau and Edwards (the 3 the NHS look for) but much less accurate for the myriad of other trisomies that you can get tested for privately. So if there’s even a question in your mind - I would go for the NIPT on the nhs.

The NIPT is very accurate for negative results. However with downs if there is a positive result there is a 20% chance that it is a false positive. For me that rate jumps up because of the PGTA

Currently there is an 85% to 93% chance this is a false positive. With an NIPT test the chance of a false posture if the result were positive is still high.

These tests are usually accurate but the PGTA is more so. If there was downs it would very very likely be mosaic downs.

The Fetal Aneuploidy Rate of PGTA tested blasocysts is about 0.13. Way way lower than natural populations

Statistically the NIPT becomes pretty unreliable because of the PGTA. Usually yes it is accurate but PGTA is very accurate. If they conflict then PGTA is still more likely to be right. Or it is this very rare mosaic downs.

I suppose as I am not going to change the outcome. So it is just about information. Given this I think for my sanity I will just go for the early anomaly scan.

with my second dd I was pregnant at 40. 12 week scan showed thickness back of neck no other abnormalities at this stage. Fetal medicine insisted I see them next day I had a CVS test which I was not keen on but took their advice as they strongly suspected downs (as scanned me again before doing it and said baby had absent nasal bone). results came back were extremely low for downs and the other two trisomies, However for other genetic conditions it came back positive for a rare one that runs in husband family we had found out about after our first baby - this baby was a happy accident(they were aware of this so added it to testing)
This genetic condition is unusual as many people who have it all very mildly affected (or not at all ) on the other scale People can be extremely affected physically and mentally and have to have support for the rest of their life.so with that information it was tough. Anyway later scan showed nasal bone was not absent but there was a hole in heart. So a rollercoaster as was told this may need surgery as large and unlikely to close on its own.
anyway fast forward 4 years I have the most amazing smart happy little girl. She wears glasses and has some hearing loss (and a lot of allergies )but otherwise she’s perfect. The hole in heart closed itself after birth. No issues with behaviour/development etc so far. I guess all the testing increased my worry and stress however I was prepared mentally that baby may have extra needs and actually she is doing incredibly well.
i think it depends on how much you want/need answers- also is it possible it’s not downs but another genetic condition ? My consultant was adamant (before results) my baby had downs but clearly they didn’t. And yes absolutely this could be nothing and I would be reassured by the testing the ivf clinic had done.
Wishing you a healthy happy pregnancy x

Thank you for sharing. I had a few minor alarms that turned out to be nothing with my first so I have some experience of getting stressed and it turns out as nothing.

I have stopped my middle of the night panic now and although I will add to my mental calculation that there may be more chance of extra medical needs.

The anomalies scan may tell me more.

I recently paid privately for a NIPT test as I was low chance, but on the borderline of being higher chance. Even though we would have proceeded with the pregnancy regardless, I felt it would give us some clarity and help us plan if positive. Results came back negative about a week later and I’m glad we did the test privately now

I get this and may have done the same in your shoes.

However if the NIPT result is different to the PGTA result then the PGTA is more accurate. That is because they could analyse a cell directly from the blastocyst instead of placental DNA from my blood stream.

The only way to be sure is to have the diagnostic test which is an amino. I am not willing to risk this.

Thank you everyone.

I get this may seem contrary and like I am ignoring you but your reply have been helpful. It is just that the NIPT accuracy for the general population is completely different than it's accuracy when PGTA testing has already happened.

I will talk to the screening midwives tomorrow and say that I will have a 17 week scan but not the NIPT.

I didn’t have a PGTA result to compare to as I didn’t have IVF. The NIPT report (or at least at window to the womb where I went) tells you the percentage of babies DNA they were able to extract which gives some reassurances to the accuracy of the test.

I would have been the same and not wanted the diagnostic test though, felt too risky. I hope everything is ok for you x