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Can you have a low NT measurement but still come back at risk on screening bloods?

11 replies

MinesALatte · 30/07/2020 17:41

Just pondering after a very successful 12 week scan, the NT was 1.6mm and I had the screening bloods - just wondering if it can still come back with abnormalities despite the 1.6

OP posts:
ivfdreaming · 30/07/2020 17:44

I think it is calculated on a range of factors that also include age and also your blood test results for PAPP-A and HCG. I've heard of lots of older women who had great NT measurements but just due to age they then were given a high risk score

WhatWouldPennyDo · 30/07/2020 17:48


My NT measurements ranged from 1.9-2.4 (baby was wriggling!) but when they ran that through the system with my bloods, I got a 1:27 risk for downs. We chose to then take the NIPT test and risk odds came back as 1:1,000,000. Felt like a lifetime waiting though!

sel2223 · 30/07/2020 17:57

Yes, as it's only one factor of a number they look at.
It's a good indicator though so I wouldnt worry unnecessary. Mine was 1.9mm and I'm 37 years old and I was low risk (around 1:8000)

bee222 · 30/07/2020 18:23

I've heard of lots of older women who had great NT measurements but just due to age they then were given a high risk score

There is a lot more to it than NT measure and age. At 39 years old with a 1.7 measurement my results were 1:12262

Somethingsnappy · 30/07/2020 18:43

They measure your hormone levels such as HG and Papp-a, and combine those levels with your age and NT measurement. Unusually low or high levels can raise your risk. But having a good scan and normal NT measurement is a great sign though! You would hear back very quickly if there was a high risk, within a few days. If all is well, you'll just get a letter through the post.
Congratulations on your pregnancy!

MinesALatte · 30/07/2020 19:17

Thank you ladies! That’s all really helpful xx

OP posts:
MinesALatte · 30/07/2020 19:22

I’m 34 and OH is 44 so not really sure where that puts me in terms of age and risk!

@WhatWouldPennyDo thank you for sharing your story, bet that was a long couple of weeks!

OP posts:
WhatWouldPennyDo · 30/07/2020 19:30

@MinesALatte hopefully everything will be ok for you. Generally there is an increase in the risk if you’re 35+ so being under that will help you. Good luck! Your NT measurement is great though, so definitely take some comfort from that (I won’t say ‘try not to worry’, as I know that’s impossible Grin)

MinesALatte · 31/07/2020 00:15

@WhatWouldPennyDo thank you! I’ll try not to worry... too much 😂😂

OP posts:
LeonieMacaroni · 31/07/2020 09:23

Both my pregnancies came back high risk despite good NT measurements at 12 week scan and I am under 30.

Both times I had a higher level of Hcg and a lower papp a level than what they deem to be acceptable. The first time I paid for a harmony which came back 1:10,000+ and baby was born with no issues. Second pregnancy was twins so they wouldn't do a harmony but CVS came back clear so it looks like that's just what my blood does. It's incredibly stressful though so I hope it comes back ok for you!

zombielady · 31/07/2020 09:39

I was 36, nt measurement of 3.8 and after bloods given odds of 1:2 (very stressful few days!) Luckily everything was fine, even with those odds!

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