NT, CVS or Amnio? what do you think?

Hi ladies,
with my lovely DD I had the scare of my life. The share-care gp sent me to do a NT scan, even though when I got to the hospital they told me it wasn't routine at my age (I was then 30 y.o). Both my partner and I don't have any family member with genetic problems and the gp told me she thought it started to be routine at 30.
Anyway we had the NT scan with a terrible girl who wouldn't answer my questions or acknowledge she heard me at all (after we gave her the time to do her job, we didn't want to distract or disturb her). She just left the room mumbling she was going to get the Doctor. Obviously we started panicking. The doc confirmed that the NT showed high risk of "something wrong" with the baby because the thickness behind the neck was more than expected. They tried to reassure us saying that this needed to be analysed through a formula once they also had the blood test results.
Few days later they called me to go as a matter of emergency to the hospital because the doc wanted to talk to me. The NT results showed 1 on 17 chances of having a baby with Down syndrome or other genetic problems. They forced us to talk to a genetic counsellor who as soon as we got in the room showed us pictures of babies with Down Syndrome. We were shocked, but we had already decided what we were going to do. They explained us that if we waited any longer and decided that we didn't want the baby I had to deliver it(that was another shock!). We asked to go for a CVS and waited the 2 long weeks to get the answer. I was crying every day during those 2 terrible weeks.
Our DD is fine, healthy and happy.

Now I am 33 (34 by the time the baby is born) and I am wondering... should I go through NT again (since it is not invasive just an US) and risk to get a false positive (again) or worst, a false negative result or should I go straight to do a CVS (with the small risk of mc) and wait 2 weeks to know if my baby is ok.

While one is a screening test and the result can NOT be 100% sure, the other one is 100% sure answers. On the other hand, there is a small chance of mc. The third test (Amnio) is a bit safer, but a bit later in the pg.

What to do? Any opinion? what's your experience?

Thanks

I wouldn't get the CVS without having the NT done. There could be no need to have it at all!

Also, you don't actually have to have the NT scan at all if you don't want to.

It's a tricky one. Given your age I'd say just go for the NT & see what the result is. Then again it is only a screening test so it's not like it gives you a result, just a risk. I had a similar experience to you but opted for an amnio. I think if I was pregnant again I'd ask if I could just skip the NT & go to the amnio, but I am almost 10 years older than you so my risk is going to be high regardless.

Don't think of it as a false positive cos there's no such thing. It only gives you a risk factor therefore you were not given a false result.

Hi,
thanks for the answers.
Satya: why would you go for amnio instead of CVS? any particular reason?
Thanks again

Amnio has half the risk of miscarriage of a CVS & as I had a history of m/c it seemed the best option. To be honest both my OB's (I had changed) both recommended amnio rather than CVS.

yep, I thought that would be the reason. Even though it's done later on in the pg...
well, I have an ob app this week. Will hear what he thinks and then decide... either one or the other though... I don't like to not know, iykwim.
cheers

What an awful experience that must have been for you... I can understand why you would be anxious about getting a misleading NT scan again after having been through what you have.

When we were deciding whether or not to have the NT scan my OB had what I thought was an interesting take on the situation. Basically he suggested that we decide whether or not we would terminate the pregnancy if we did find out that our baby had Down Syndrome before deciding to have the NT scan. If we would terminate, he then said that we should go ahead with the NT scan and any other testing that was necessary to determine it. But if we were of the mind that we would keep the baby he recommended that we not do the NT scan, because then if it indicated a problem you would be risking miscarrying a child you intended to keep with an amnio or CVS.

I'm not necessarily sure that I agree with the logic, but it is an interesting take on what is a terribly difficult decision...

Good luck with it all!

Thanks MissExcited,
we have already decided with our first baby what we would do and we maintain the same decision for baby No 2. We had a mc between No1 & No2 and we know how it feels loosing a baby.
On the other hand we can't bring ourselves to give life to a baby that may suffer from day 1. We have done lots of research and we have talked a lot about it and we have reached our conclusion. We respect others opinions and decisions on the issue, but we have reached our own.
Hence my need to know and the choice between different tests.
I do appreciate your suggestion, it is exactly the thinking we used with our DD. I am glad everything ended up fine with her and that she is the happy toddler I love so much!
good luck with your pg.

Hey Titti,

I'm having to make those same kind of decisions, I will be 37 by the time the baby is born so thats against me. I'm having my NT on the 16th, I had to make the decision to do the NT and bloods or go straight to amnio or CVS. I decided CVs was too risky for me, amnio risk is more then enough for my to get my head around.
Its a big decision to make and I get very scared about Amnio but I feel it's the right decision for me and my family.

All the best with everything
Cheers Missy

Hi Titti,

DH and I are going through a very similar thing - as you can see by my sig.

Our original diagnosis was 1:2 of Downs and 1:6 of Trisomy 18. I insisted upon a second scan (had to have a third 'cause they got all confused) and now our odds are 1:230 of Downs, no risk of Trisomy 18. Soooo inaccurate and questionable. How the odds can change so fast is beyond me.

I am having an amnio on Wednesday next week. Not necessarily to determine termination, but rather so that DH and I know for sure what is going on. I would like to sit back and enjoy my pg, not worry about what may or may not be - just as I am now.

I am glad to hear it ended well for you!!

I would go for an NT again, if I were to have another baby. BUT (big BUT) have a different sonographer.

thanks lestypuss.
your terrible experience is exactly what I want to avoid. You had to ask for a second or third scan... you!!! not the doctor, but the distressed parent! How can that be possible?
This time I would go through a private UltraSound company (very competent and specialised in pg women), but the result would still be just a screening and it is not 100% accurate. Which means they can tell me everything is fine and later found out it is not or viceversa...
I am very confused. I can't see the point of doing an NT if I know I will go for a CVS or Amnio. Well today I have the first appointment with the OB, hopefully we will do an US and see that the baby's heart is still beating (not like in June)... then we will decide.
Thanks to all of you for your words.

titti, what happened?

I insisted upon the second scan because I thought she'd stuffed it - and I was right. Because the second scan showed a discrepency the Dr wanted me to go for a third. If the risk was low, I wouldn't have had the amnio. But it's still higher risk than they like - hence still having the amnio. I had the same sonographer the whole time. Mostly because it's a public hospital and around here there isn't any other choice unless I travel three hours to Adelaide.

hi,
I've been to my new OB, who is great!
THe US was good too, baby's heart is beating and baby growing perfectly! I'm relaxed now... We have talked to the OB about our bad NT experience and I listened to his suggestion... so we will go for an N-T and if it shows that everything is fine we will do an amnio otherwise the CVS.
In Europe they DO NOT believe in N-T, there is too much uncertainity and is not 100% accurate. On the other hand if you are over a certain age you are strongly suggested to do a CVS or Amnio.
After my bad experience in the public hospital, I decided to go private for everything, and especially for the US, N-T and CVS or Amnio. THe risk is even smaller because they do only that and just that all year around. So hopefully everything will be fine.
Thanks for everything
xxx

hi hun,

if you do hav the nt and have a high risk (as i did) you can get the cvs done straight away and pay a little extra to have the results within 24 hours, some of the best dollars i ever spent!!!

cvs does have a slightly higher risk, however it is earlier on in the pregnancy, where the risk itself is still higher... kwim??

i hope there is no need to go through it, but if there is we will be here for your 24 hours of hell post cvs :hug:

thanks Kit3n!
we had the scare with our DD N-t but in the hospital (public) they never told us that we could get a quick result for an extra fee... if only!!! I spent 2 weeks crying and fearing the worse (we did decide we weren't going on if the results confirmed serious problems with the baby)... 2 weeks of living a nightmare... but all was good at the end.
thanks for your support!!!
xxx

Hi titti,
i'm so sorry you had to go through such an awful time with your last pregnancy and completely understand that you would want to avoid the entire situation. From experience (professional, not personal) it is a tough decision to make, and one that depends greatly on your personal beliefs.

Yes NT is a screening test and only identifies babies that are at a higher risk than normal, but it is also non-invasive and carries no risk to you or your baby. Many people choose to have this done because they a) would like the heads up that there might be something wrong or b) purely because it is available and they think they should or c) because if something was found to be wrong with the baby in later tests they would opt to terminate. I am planning on having an NT, just because if there is a higher risk i would like to be prepared for a baby that may have a disability, even though it would not change my approach in having the child. Others may find the wait and the rest of the pregnancy too stressful and hence opt not to have the NT, as they would not terminate if there was a problem anyway.

The beauty of an NT is that it is non-invasive. Amnio carries a <1% risk of m/c and i believe CVS has a 1% risk of m/c. Again this depends on the individual as to whether you want to know because u can prepare, or you want to know because you would terminate. Also, one must not forget that medical tests are not perfect.. a high risk NT may in fact be a completely healthy baby, a low risk NT may still have a disability, a positive amnio/CVS may be falsely positive and a negative amnio/CVS may not have detected a child with a disability.

at the end of the day, it is a very personal choice and difficult to weigh up. i probably have just added to your questions rather than helping you answer them. The best advise i can give is to find an OBGYN or midwife or GP who you trust and develop rapport with and whom you are comfortable discussing these concerns with. Then they can tailor their advise to your individual concerns/needs.

Good luck. I'm sure you will do the right thing for you.
xx

THanks Emmykate82.
I never heard of any false result with Amnio or CVS. I thought (and read) that they are 100% accurate in diagnosing genetic anomalies.
Does anybody have different info? I am very interested in this.
thanks

I too have never heard of a false result with an amnio or CVS and am very interested to know if this is possible.

I wouldn't have thought so.

CVS takes cells from the placenta. Amnio takes cells from the amniotic fluid that have been shed from the baby.


CVS
Baby and placenta are both produced from the original egg + Sperm. The sperm enters the egg and then these split into 2 cells, and then 4 cells....

Presumably, all these cells are identical to the original cell, but sometimes there are slight changes.

Early in this splitting, the cells that produce the baby are separated from those that produce the placenta. The baby cells keep dividing making the baby. The cells that go to make the placenta also keep dividing, but are no longer part of those that are making baby.

It is possible that something happens to one of the cells that are dividing to make the placenta, that do not affect the cells in the baby. This cell will keep dividing and will form part of the placenta.

When a CVS is performed there is the chance that this 'change' that has occurred (e.g. an extra chromosome or minus a chromosome) will be detected in the placenta even though the change is not present in the baby.

If this happens, the lab will see some cells that look like the baby (the cells without the change) and some cells that will have the change.

The lab knows that some changes only occur in placenta cells (if it happened in a baby cell, the baby would not keep growing) and therefore they know that they don't have to worry about these changes.

Some changes detected through CVS in only some cells are harder to work out if they will affect the baby because they would still produce a viable baby (e.g. 3 copies of chromosome 21).

If some 'normal' cells and some cells with changes were detected through CVS, they might suggest to the Mum that she have a follow up amnio to confirm.

This would be very rare, but it is a possibility.

For a CVS to have completely 'wrong' results (ie the results from the cells taken from the placenta are not the same as the cells that make up the baby), a change in a cell must have occurred very early in a cell that makes the placenta. and this cell, must have made all the subsequent cells in the placenta and have contributed no cells to the baby.

This situation is almost so so so so rare to occur that i don't think it has ever been detected yet.

Amnio

The cells analysed using amnio are closer (than CVS) to the composition of the cells in the baby, because the cells they look at come from the fluid surrounding the baby. So these cells have come from the baby and have had less time to have changes occur (that aren't already present in the baby).

Summary

So, it is possible for CVS to produce uncertain results but this is rare, and the lab can usually tell whether the changes detected will affect the bub. Overall, both CVS and amnio are in all but the rarest times quite definitive in the results.

Kate - thank you for taking the time to provide the details.

Thanks Kate,
what you said certainly makes sense!
I really appreciate your message, I was quite surprised and confused about the chances of not being accurate.

Hi ladies, I have never posted on a forum before so I hope I dont press the wrong button. I have been through 2 x high risk downs probablilities, the first 1 in 200 (perfectly normal little boy nearly 3 now) the second 1 in 2!! With both I had the CVS and both came out normal, no problems with either CVS (number 2 is still cooking). Its up to the idividual but especially with number 2 I couldnt BARE not knowing, I was simply beside myself with all kinds of dreadful emotion. I cant even begin to tell you the releif I had when I found out there was a normal little baby growing in there and no longer have to think of the consequences of a positive result later on in the pregnancy. I dont really have an answer as to whether one should go for CVS , amnio or not, I guess I just want to say, I have survived CVS twice (im 37 by the way) and have had normal results from the worst possible risk scenario.

Good luck to everyone.

Hi Everyone,

I had my NT scan yesterday and because I'm in NZ I now have to wait till I'm 15 weeks and have my bloods and then wait up to 10 DAYS for my ratio results!!! talk about torture!
On a positive note the Dr doing the ultrasound said the measurement was only 1.6mm and that that was normal and that she could see nothing at all that concerned her so thats reassuring.
I know my bloods will have an impact due to me having just turned 37 last week so I will be so pleased to have the results one way or another.

I hope everyone is well
Cheers Missy