very different nuchal fold test results

[babyworries]

Hi

After advice from friends I decided to have a private 12 week scan done at The Fetal Medicine Center - and the next day had my 12 weeks scan at UCH.

I wish I'd thought more about this beforehand and decided not to go ahead as my partner and I have been down a long road of IVF and I cannot imagine deciding to terminate if there is something wrong. I never felt like there was a choice (clearly I didn't have to go privately) but the NHS 12 week scan is just given to you as a fait-accompli without anyone advising you that you may then face a very difficult decision that runs a risk of miscarriage.

Apparently my risk factor as a I walked through the door as I'm 42 was 1 in 38.

The FMC gave me 1 in 40 which puts me in the high risk category for Downs (which I understand now I was already in anyway). Everything on the scan was normal (heart, nasal bone, size, bloods etc) but the nuchal translucency measured 2.9mm which is outside their normal range. The baby was very active which I understand from other sites is a good sign of no problems - but makes it more difficult to get a correct reading.

UCH gave me exactly the same test ( it also included a transvaginal scan which apparently gives more detailed results - although not for nuchal fold). However their results were entirely different. Every marker was normal including the nuchal fold which they measured at 2mm. They were very pleased with the results and said it was a good scan as the baby was still enough for them to get an accurate reading. They said my risk is now 1 in 1080.

How can these results be so wildly different? I tend to believe the FMC as it's a specialist clinic (although it wasn't Nikolaides who scanned me). I checked out the guy who scanned me at UCH and he is a very well respected gynaecologist.

I don't think I want to go through with a CVS as I'd never forgive myself if there was nothing wrong and I then miscarried after everything we've been through. Even though they say it's 1% it still feels too risky especially when I cannot imagine terminating.

Clearly this is not an exact science. I cannot believe that women are being put through these stressful tests and there appears to be such a huge margin for error.

Has anyone else experienced anything like this?

Hi

So we went back to the FMC this morning - and they re-did the test. The woman who did the scan said there was a possible explanation for such a wide discrepancy in the results - which was that the chord could have been around the baby's neck which is nothing to worry about but can increase the nuchal fold width - and that it's a very difficult thing to see on the scan. At last a possible explanation!

She also said that it was a very wide discrepancy and quite unusual - which was not what the previous scanner said. She did the whole test again and everything was as before apart from the crucial nuchal translucency test. She measured it over and over and it came up consistently as 2.3mm. She said this would be consistent with UCH's results as the baby has grown significantly in the last 10 days and the measurement goes up as they grow.

She then left us on our own for about 25 minutes - I imagine that she'd gone to consult with Nikolaides - and when she came back she apologised and said she believed that UCH had got the measurement right. She reassessed our risk and it came out as 1 in 800. Obviously we are hugely relieved.

Based on there initial results, we may have decided to go for a CVS which would have put our pregnancy at risk for no good reason. It amazes me that something so important can be left to such an untrustworthy system. How many women out there are having completely unnecessary CVS and amnios and going on to miscarry? It doesn't bear thinking about.

We are very lucky I know to have had such a positive outcome in the end - and I know many women out there are struggling with high risk results and painful decisions. My heart goes out to them.

Debs3013 - I was thinking about you this weekend - have you had your results yet?

Glad you got some answers. Those odds are really good now. I think generally the systems work well, seems you had a difficult experience but at least you know where you stand now.

Good luck for the rest of your pregnancy!

I just want to add to this thread that I find myself in a similar (agonising position) tonight this morning. I am 12+2 and went to the FMC for a nuchal this morning, follwed by an NHS nuchal at C&W this afternoon. FMC gave me an overall risk of 1 in 1200, which I am happy with. But, the nuchal measurement was 2.8mm, which I and more so DH are not really comfortable with. The scan at C&W gave us a measurement of 2.1mm, which I am happy with.

So, it seems I too am having the same experience of everything but the actual nuchal measurement at FMC of being fine. But, why the discrepancy in nuchal measurements over a period of 6 hours.

DH wants CVS but says it's my choice... but he obviously wants it. I keep looking at the 1/1200 and thinking the risk of miscarriage at 1/100 is far greater than the risk of having a Downs baby so am inclined to chuck out the FMC nuchal measurement and look at all the other data, which is all reassuring. Oh, bytw, I am 40. So my risk on age alone is 1/64.

Another thing I have noticed is that FMC got a crown rump measurement of 64.8 and C&W got one of 58.9. FMC measured NT at 2.8 and C&W at 2.16. And dates based on size put me at 12 +6 at FMC and 12 +2 at C&W (C&W is bang on my my LMP dates. Sooooo... I am wonder - sice all of FMC's figures are a bit higher than C&W's - if the explanation could be the machine and not it's operator. Is it possible the FMC (or the C&W one) is not properly calibrated.

Babyworries, do you happen to know what scan room you went into at C&W (assuming they have not moved the machines around)? And did it's operator by any chance bear the first name of a main biblical character?

I am totally confused... oh, did you get your second FMC scan for free? I don't really fancy shalling out another £150 for more inconsistent data.

Also, the FMC scan was hugely more thorough. The NHS one couldn't get us in and out fast enough and I had to drag the actualy nuchal measurement out of her - was not impressed by her reluctance to share information.

Sorry for the momouth post. I really should be in bed. But just can't sleep.

Those differences in measurements are actually tiny and the size of the nuchal folds are still well within 'normal'. Sonography isn't totally exact so the discrepencies are expected and in your case are really small tbh.

Your odds of 1 in 1200 are fantastic. Personally I wouldn't jeapordise a pregnancy for those odds. However it's your choice obviously.

Not sure why you would opt for 2 scans of the same type either tbh. I only paid for mine as the NHS one isn't available here. There is always going to be a discrepency between scans - however small. Not a criticism but just think it's never going to be helpful or give you exact results. I think you have to accept one or the other and go with that.

Good luck with your pregnancy.

hey there Persnickety,

I saw your other post in the 40 thread

I think your DH is probably being too cautious and your risk sounds very low. I agree that you have to weigh up the miscarriage risk against the other risks and so in your case the further testing might not be worth it. I felt quite a lot of pressure from my husband but have decided to go for the Amnio now.

My measurements were really different too. At the private scan the baby was measured crown to rump and was 64.4, so similar to you. At the NHS scan 3 days later they only measured the crown but told me I was a week further on than I could possibly be - I know for sure because I had IVF. They didn't measure the nuchal fold at my NHS scan unfortunately.

I think the measurements can differe from machine to machine so far as dating the baby goes - I was told it can vary by 5 days sometimes.

babyworries congratulations on the successful IVF. I know how scary all this is and I thought it would all stop after the positive test. Great news that your risk has been re-assessed.

My nuchal fold measurement was 2.4 and my overall risk was is 1:80 (starting risk of 1:70 because I am 40) so I am going to have the Amnio.

sorry - starting risk of one in 77!

i think reality is you need to be much more worried if nuchal fold is way off scale ie something like more than 4mm. at the just beyohd normal range is even more of case of statistics/risk/guesswork.

with these results you can wait for detailed anomaly scan at 20 weeks and see if any other markers come up - or go for 4-d scan if you want further info before birth.

i had substantially increased NF with my son (was 13 years ago - dont have actual figure) and there were then also anomalies on 20 week scan - he does not have downs but does have a microdeletion syndrome not diagnosable on current Amnio/CVS.

My sister is going through something similar, the nuchal fold measurement is 6mm. She had all the test things (sorry not to sure of the correct names of them) she was given a 1 in 2 chance of downs and a 1 in 5 chance of a problem that wouldnt be compatable with life but it has all come back clear of any chromosome problems. Scans have shown that her baby (a little girl, it's so cool knowing for definite at only 13 weeks!) has a leaky heart valve which is probably causing the increased fluid build up.
Good luck to anyone having amnio and awaiting results