6mm NT at 20 weeks scan as soft marker for Down's after low risk 1st trimester screening...not sure what to do

[Pugalina]

Hi everyone,

I had my 20 week scan this week and baby was in an awkward position (head all the way down in my pelvis) and the sonographer struggled to measure the baby's head and brain properly and she measured the Nuchal Fold Thickness as 6mm, but she said it could have been because of baby position, that she struggled with the measurement, but because it's right on the border of what's considered normal they booked me in for another scan the next day with the consultant. When I had the scan with the consultant, it was all very fast, he said he couldn't measure NT at all because of baby's position (didn't ask me to shift position or try to move baby or do anything) but that he looked at the scan from the day before and that he thinks that measurement was accurate, which means there's a small risk of Down's and we should either get an NIPT test or the amnio directly (they kept trying to push this on us). I was extremely shocked to hear that, because at my 12 week scan NT measured 1.3mm and my screening result came back as 1:16,710 for Down's so low risk, and I expected they would measure the NT again to confirm, but instead they told us there's no other scans they can do and to get the NIPT or the amnio which I'd really want to avoid (I have an anterior placenta and I'm RH negative so don't want to risk any bleeding).

Has anyone gone through anything similar and what did you do? Has anyone had a NIPT test after having a low risk initial screening result? I'm extremely confused and worried. Thanks!

Sorry you’re going through this, it sounds so stressful, especially after thinking it was all behind you with such low risk from the 12 week scan. I can totally understand your reservations about an amniocentesis, but what are your reservations with the NIPT? I thought these carried no risk and were very accurate? Sorry not to be more helpful.

I had a nipt after a high NT at 12 weeks. It was straightforward and carries no risk (unlike an amnio). If I were you I would definitely do the nipt to find out more.

Sorry to hear you are having to deal with this stress. I had NIPT with my first baby and have booked for a second one now I'm pregnant again. I wanted it for reassurance because it's so much more accurate that the scan measurements or the 'likelihood number' the NHS gives you. It carries zero risk to you or baby because they just use a sample of your blood. It is worth every penny in my experience.

Thank you @AutumnVibes and @Houserenoqueen I will definitely have the NIPT - with the NIPT do you get an actual result of 1:x or is it just low risk/high risk general classification? It's more the stress of having to deal with all of this so unexpectedly and I know that the NIPT should come back fine, but there's that tiny possibility of what if it's not...and it also seemed like such a small thing for them to go straight into 'you should get the test or do the amnio', without even repeating the initial measurement (despite sending me for a second scan), so I was wondering if anyone else has experienced something similar with their 20 weeks scan after having low risk at the 12 week one and the initial screening test and what they did/what the outcome was?

@Hummingbird20 thank you, how soon do you get the results and is it just for the chromosomal abnormalities or other stuff too? Or does it depend on the actual test you take? I've been recommended the IONA one through the NHS (but you still have to pay for it).

@Pugalina I too chose to pay privately for a NIPT this pregnancy. Just due to my age and wanting a more reliable result than the standard nhs screening.

I got my results exactly 7 calendar (not working) days after the test. It stated my results as 1:100,000 of the trisomies tested for.

Also just to reassure you, the actual nipt is perfectly harmless, literally a blood test for you. I have an anterior placenta but they don’t touch your abdomen (apart from a scan). It was literally like every other blood test I’ve ever had.

Thank you @Moominmiss that's helpful to know. Glad your test came back with such a low risk! Which one did you have, do you have know? I've been recommended the IONA test.

Hi @Pugalina. We had the IONA test as it was offered by our trust after our combined screening results came back high. I had the blood test on the Tuesday, dropped it off at the post office and amazingly had the results by the following Monday - I was expecting a longer wait. They gave us a risk of 1:10000 as well as a ‘low risk’ and the gender of baby.

The only thing I would point out is the NIPT test isn’t diagnostic. We had already agreed that if this NIPT came back as high we’d have an amino to try and get a diagnosis but as we were only 13 weeks we didn’t want to have to wait and worry for a couple of weeks until we could have the amino.

I’m happy to try and answer any questions you may have xx

Thank you @Wibblewobble99 I think if the NIPT comes back low risk then that will give me the peace of mind I need as it's only this NT measurement that is right on the border and everything else has been fine so far, will only have the amnio if it comes back high risk. Glad your test came back with such a low risk!

Thank you. It was a horribly worrying time, my thoughts are with you and hoping you get an equally low risk. X

@Pugalina I opted to have the SAFE nipt. We had it done at the Birth Company on London.

Thank you @Moominmiss, I've managed to book the test for tomorrow, will have the IONA one.