NT 1.5mm but no blood test

PPop · 2023-03-12T19:40:56+00:00

So I had my 12 week scan on Wednesday past, but as I had a vanishing twin I couldn't have the bloods for downs/Edwards/patau screening due to the twin hormone throwing the test off. NT measured at 1.5mm which is well within normal range for 12w 3d measurement. I have been told I can have the NIPT test but this will be later on in the pregnancy. I don't really understand it all but it seems NT is only downs related? I am trying to work out if I should be concerned/find out how soon I can do the NIPT test due to hormone situations if anyone has any advice to soothe my worried mind. For information first pregnancy at 35.

Whentwobecomesthree · 13/03/2023 13:43

I had a similar situation recently. Although the vanishing twin was discovered at my private NIPT appointment at 10 weeks. I did have the combined test on the nhs, the NT was 1.7mm. I got a 1 in 500ish result for DS, much less for Edwards and Pitau.

I then had the NIPT at 15 weeks and got a low risk result. They advised not to have the NIPT until 8 weeks after the vanishing twin pregnancy ended. Which they calculated as between 6 and 7 weeks.

I think the NT is relevant to Edwards and Patau as well as Downs. But your NT result of 1.8 is good

Whentwobecomesthree · 13/03/2023 13:46

You can still have the combined test (blood and NT) but it's just not as accurate as they have to discount one of the hormones (Papp-A I think). Hence why they often suggest an NIPT too. They do this once the right amount of time has gone by to not pick up any genetic issues that caused the vanishing twin to not progress

royalrecording · 13/03/2023 13:58

I had a (significantly) raised NT measurement with an Edwards diagnosis, if that helps.

Original poster

PPop · 13/03/2023 14:53

They said they wouldn't do the bloods? So I didn't get them done as it was a refusal? Now I'm wondering if I should have pushed/should ring my midwife and ask for bloods to be arranged?

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Whentwobecomesthree · 13/03/2023 20:00

Might be different protocols at different nhs trusts. At mine your bloods are taken before your scan so they already have them. They did say they weren't as accurate but never suggested not valid. Worth asking.

royalrecording · 14/03/2023 10:43

I’m not sure why you’d push for the bloods when knowing it would be an inaccurate result. NIPT is the better test so if I was going to push for anything it would be clarity on when you could have that and making sure it gets booked in for you.

Original poster

PPop · 14/03/2023 16:04

royalrecording · 14/03/2023 10:43

I’m not sure why you’d push for the bloods when knowing it would be an inaccurate result. NIPT is the better test so if I was going to push for anything it would be clarity on when you could have that and making sure it gets booked in for you.

Because and apologies if I've read responses incorrectly but it seems that the bloods can be done they are just slightly less accurate but not - as I believed - completely pointless. That is why I asked if people would push.
I don't think downs is a concern as per the 1.5mm measurement but the more concerning issues I may have to wait until 20 weeks for answers which seems concerning to me.

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royalrecording · 14/03/2023 16:25

PPop · 14/03/2023 16:04

Because and apologies if I've read responses incorrectly but it seems that the bloods can be done they are just slightly less accurate but not - as I believed - completely pointless. That is why I asked if people would push.
I don't think downs is a concern as per the 1.5mm measurement but the more concerning issues I may have to wait until 20 weeks for answers which seems concerning to me.

Show quote history

Sure I can understand wanting as much information as possible, I’ve been in the position of getting troubling results at the 12 week scan and having to wait for more testing etc. But say you get the results and they give a high chance of one of the syndromes - you may be subject to a lot of worry for no reason. Or if it comes out all clear this could be a false reassurance. It sounds like you don’t yet know when you can have NIPT, so that would be my first question to the midwife. She may say you can have it in a couple of weeks in which case it’s a no brainer to wait (in my opinion).

The bloods only test for Edwards, patau and downs. All those three syndromes are associated with increased nuchal thickness and other abnormalities detectable via ultrasound so hopefully you have some reassurance that there is currently no evidence your baby has any of those conditions.

Again having been through the awful process of receiving an Edwards diagnosis I do understand what a worrying time it is but for me personally I would be pushing for the NIPT as soon as possible instead of the combined blood test that could give confusing or stressful results. I would also consider contacting a private clinic that offers NIPT and seeing when they would be willing to administer the NIPT. Even if that’s not affordable for you it’s extra information that could help with your conversation with the midwife.

Original poster

PPop · 14/03/2023 16:34

Thank you @royalrecording I am sorry about your previous diagnosis and appreciate the help. I struggle at appointments to take stuff in I think at the moment as it's just so much to take in and I'm an "older" mum hence the deep concern.
Hopefully the NT being so little is a really good sign. I next see the midwife on 3rd April but I have a consultant appt before then so I could ask questions to him 😊

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royalrecording · 14/03/2023 16:40

@PPop understand completely and hope you find the right path forward for you. Let us know how you get on and don’t be afraid of contacting the midwife or the consultant before your appointments, it’s normal to have follow up questions after an appointment.

Original poster

PPop · 16/03/2023 10:36

Hello,
I have had this today, so I am more confused as it states no further testing? Can anyone advise before I ring the midwife for the second time today 😂🤦‍♀️

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royalrecording · 16/03/2023 18:43

Looks Like they’ve calculated your odds based on age, NT etc and not including the blood tests. Good that they’re so low! But a bit at odds with what you were told about being able to get NIPT later, right?

Original poster

PPop · 16/03/2023 19:22

royalrecording · 16/03/2023 18:43

Looks Like they’ve calculated your odds based on age, NT etc and not including the blood tests. Good that they’re so low! But a bit at odds with what you were told about being able to get NIPT later, right?

Yeah it feels strange to have calculated my odds with not the full data to hand? I'm a little miffed at the change of plan and now if I want a NIPT it's £275. More annoying as I'm such an anxious person about all these things, I said on the phone but couldn't the bloods have changed those odds she did agree with that thought which hasn't helped 🤦‍♀️😂

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Whentwobecomesthree · 16/03/2023 20:08

Just fyi if you get the NIPT privately, you can't have the Harmony test with a vanishing twin pregnancy. You can have the SAFE test though

Original poster

PPop · 16/03/2023 20:21

Whentwobecomesthree · 16/03/2023 20:08

Just fyi if you get the NIPT privately, you can't have the Harmony test with a vanishing twin pregnancy. You can have the SAFE test though

What does that mean sorry? Would it be less reliable?

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Whentwobecomesthree · 16/03/2023 20:53

No I don't necessarily think so. They are just different versions of the NIPT test. There are Harmony, SAFE, Panorama, IONA maybe others. Different providers might offer different tests. My hospital only offered harmony which I couldn't have with the vanishing twin so they recommended that I get the SAFE test privately. I just didn't want you to book and pay for a harmony test (it's the most common) you can't have.

Original poster

PPop · 16/03/2023 21:00

Thank you! I appreciate all the information possible. DH looked at the results and doesn't see why we should spend £275 as in his mind he doesn't see that some data has been missing so it might not be correct...

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Umbuster · 18/03/2023 05:46

@PPop I also had a vanishing twin at 6 weeks and had to wait until my body absorbed the placenta and sac. This wasn’t confirmed until my 16 week ultrasound. At that point, my maternal fetal doctor told me I could have the NIPT done to confirm baby did not have any genetic abnormalities.

2021ivfagain · 17/01/2025 18:56

@Umbuster I know this is an old thread. I had a vanishing twin at 8 weeks and waited a long time to have my nipt. I had nipt at nearly 20 weeks and waiting for results. I kept getting conflicting information. Do you mind me asking how you got on with the nipt?

Umbuster · 27/01/2025 02:27

2021ivfagain · 17/01/2025 18:56

@Umbuster I know this is an old thread. I had a vanishing twin at 8 weeks and waited a long time to have my nipt. I had nipt at nearly 20 weeks and waiting for results. I kept getting conflicting information. Do you mind me asking how you got on with the nipt?

I’m sorry I can’t be of help because I did my NIPT test before I found out about the vanishing twin. My doctor told me it was likely that the results would come back abnormal/say something was wrong but that I needed to ignore that since there was a vanishing twin. I decided not to proceed with another NIPT test to avoid any anxiety as the doctor was confident at the 20 week ultrasound that my baby was developing normal and there would be no abnormalities. My baby is now a happy and healthy 20 month old.