To have a termination based on a nipt result

[Fliss89]

We had a nipt test a couple of weeks ago and it came back high risk, to cut a long story short we went for a cvs yesterday and they couldn't do it, have to go back again next week when I'll be 14 weeks.

Failing next week I have to then have an amino at 15 weeks. My issue is... I asked the consultant how accurate the nipt was and she said it had a 0.01% false positive rate.
Mentally still being pregnant knowing the outcome is pure torture waiting around for all these tests when it's highly likely the baby does have the condition. I'm torn what to do?
If I have a termination prior to a diagnostic it has to go down as a section C "social termination" over a section E for fetal anomaly. This means I won't get any extra support if I get pregnant again, it's also very upsetting to me that will be on my records when this is a wanted baby.

It said greater than 1/20

@sturdyartichoke yeh I asked if that was just in the nhs or across the board including the private sector and she said across the board for nipt with t21. I had always heard 1% but not 0.01%.
The ppv in the literature of the brand of nipt I used (nifty) says 92.19%, sensitivity of 99.17%. I guess I'm boggling my mind with numbers clinging on to a scrap of hope but when the consultant said that to me I just cried and thought what am I waiting for.

I would recommend waiting for the amnio. We were in a similar position whereby our CVS wasn’t totally conclusive (ours wasn’t a condition reliably detected by nipt) - some very slight suggestion of mosaicism. Those weeks were pure torture; I do not exaggerate. However, ultimately I am glad that we did wait for the amnio and had a definitive answer. It didn’t end well for us, but those few more weeks did mean our baby was a bit bigger and we got to hold her, have hand/foot prints done etc. Not for everyone but that was helpful for me to process the loss.

Also highly recommend speaking to ARC, as mentioned by others above.

Greater than 1/20 is more than 5 out of 100 of people getting the same result as you are affected by what is being tested for (but not a lot more because then it might be described as, say more than 1/10 ).

In other words up to 95 out of 100 people getting the same result as you are not affected by what is being tested for.
The 99.9% confidence is about confidence this is the right estimate of risk.

Unless someone in this medical field knows differently about the statistics of this test. (FYI I am quite mathematical but not a medical statistician).

Good luck

I'm sorry you're having to go through this.

This is an (oldish) blog post from the Nuffield Council on Bioethics where they talk about some of the concerns they had about communicating clearly with parents when NIPT first started to become more widely available.
www.nuffieldbioethics.org/blog/nipt-private

Unfortunately it sounds like the person who spoke to you fell into the trap of speaking about statistics they didn't properly understand. If you feel up to making a complaint/comment about this with the hospital further down the line it might make things better for the women that follow you.

There is a chance, small but it's there and not 0.01%, that you have a false positive and if your scan didn't show other reasons to be concerned then I'd urge you to wait for the diagnostic test although I also understand the agony of that wait.

Talking to ARC might help with the statistics and also to vent a bit.

This. I think you're misunderstanding the statistics. Greater than 1/20 still means the probability is that your baby is fine. There's a higher than average risk that something is wrong, yes, but it's not anywhere near 50%, let alone 99%. (It's actually around 5%.)

I am also maths-y but not medical so open to correction but I'm pretty sure this is how these tests work.

1/20 is high but definitely could still be clear. I would wait for amnio as it may not have the condition. It would be heartbreaking to find out after termination and autopsy/testing that it was clear.

1/20 means there's a chance. I know it's small but it's there.

Sorry it's not small. The chance is high. There's more chance of having the condition than someone who got a 1/10,000 result, but that doesn't means your baby has it.

I think you should go to the doctor or ask for a genetic counsellor for them to explain it to you again.

False positive rate is actually far higher for that and dependent on which abnormality you mean. NHS has the stats

I just wanted to update this thread for anyone that maybe reads in the future and also to say thank you for everyone's replies.
Sadly the cvs has confirmed the nipt result and we'll be going ahead with the TFMR. I am however glad that I waited for that diagnosis as horrible as the wait has been x

I'm really sorry to hear that OP

Nothing is going to make this feel better but it is always better to have all the facts and then make the hard but right decision.

💐💐💐

Lots of love to you OP. I'm so sorry

I’m very sorry OP x

Really sorry to hear that OP, thinking of you