high risk nuchal scan/blood test but CVS normal

[inglis]

Hi everyone
I am 35 years old and p/g with my 3rd child. Last Friday, I went for a 12 week nuchal scan and was given a 1:15 chance of having a child with trisomy 13/18 based on blood readings and a nuchal scan reading of 3.6mm. I immediately opted for a CVS. After a horrible wait of 5 days the results came back, today, normal. Of course, I am so happy but am aware that we're still not out of the woods. (ie Cardiac scans etc to come) I would love to hear from anyone who has had a similiar experience. Am I silly to feel hopeful that all will be OK in the end? Or could the increased nuchal fold/poor blood tests indicate some other abnormality that I should be aware of?
Please help -if you can.

Are they doing a chromosome check as well (a karyotype). Because of the speed with which you have got the results it sounds as if they have done a DNA test- so they will have actually looked for trisomy 13 or 18 and possibly not much else. A karyotype checks all the chromosomes- it isn't always as sensitive as a specific test but will pick up more problems.

A friend had a very large nuchal fold reading. The DNA test for Down's syndrome came back negative- then a week or so later the karyotype came back as XY/XO mosaic. Basically that meant that some cells were missing a Y chromosome. She was scanned- and as the baby was a boy no-one was very concerned. Her son is developing completely normally and is 3 now.

Do you have a number you can ring to see whether any general chromosome checks are being done- and when you will get the results.

REmember nuchal fold is just a screening test- so no you're not silly to feel hopeful. My friend had a high reading, but no further tests and her son was absolutely fine.

the boy bit was reassuring as if there had been problems from the missing Y chromosome then he may not have developed as a boy.

Jimjams, you obviously know your stuff so I don't know why I'm adding this, but I was always under the impression that the nuchal fold was a screening test and the cvs was a diagnostic one so that with the results of the latter, one could breathe a sigh of relief (at least with regard to what is being diagnosed.)

Well, your nuchal fold test plus blood test gave you a 14 out of 15 chance of a perfectly healthy baby - so it's not really surprising that the CVS confirmed it, is it? I don't think you are silly to be hopeful at all. After all, the odds were always very much in your favour.

I'm pretty certain JimJams that this is a chromosome check - in two weeks I get the results for rarer chromosomal defects.

I suppose what i worry about is the increased nuchal fold/poor blood tests point to some other abnormality that I don't know of yet. I can't quite get my head around the fact that having been told that these tests might indicate that the babe has a fatal abnormality now all is hunky-dory again. Ah well. I wait and pray.

I had exactly the same. Low ratio with pg3, followed by normal CVS and then heart scans. All well ds is nearly 1 and huge and active etc etc.

I know what you mean tho'. First two pgs were just fine, but my brain went into overdrive and I was convinced that my pg3 would go wrong somewhere. I put it down to hormones, retrospectively.

well, there is still increased risk of cardiac and neurological problems, even with normal chromosomes. Forgotten the website I used to read, from prof Nicolaides who has done lots of research in London. Anyway, was told if cardiac scan and anomaly scan were ok, then not to worry...

Having said this, dd has turned out just perfect....

fetalmedicine.com
click on 11-14 week scan book, only 100 odd pages

thats good that CVS so far shows good results for trisomy 13/18. nuchel and blood tests are just screeening tests.

Try to feeel positive. cardiac scans are ok, very scary and they do put pressure on your bump and feel achey afterwards, but generally ok and actually quite interesting. where will the fetal scan be done?

I posted a reply which hasn't shown....

I'm sure you would never do this Jimjams, but I sometimes preview, look at the post and then go straight to Active Convs so my post doesn't appear. If you can find your post that would be good, you're so much better at explaining these things than me....

Basically I said that moondog is right- the results so far show that trisomy 13 and 18 can be ruled out. It sounds as if they have done a DNA check on that- the test effectively counts the numbers of chromosomes 13 and 18 - but without anyone looking directly at them. The results coming through in 2 weeks will be the karyotype results. This is when they actually look at the chromosomes down a microscope- it takes 2 weeks as the cells have to be grown. It's at this stage that problems like my friend's XY/XO mosaic would be picked up. However however however the nuchal is just a screening test - so I was trying to reassure that having had the all clear on trisomy 13 and 18 its likely that the nuchal just gave a false positive- it does happen fairly often- and that all is well- and this will soon just be a bad memory.

ah probably did something like that tamum- have total pregnancy brain. I was just thinking we needed you as you're better at explaining this than me

I'm off to make my name xmassy.......

Thanks everyone for the comments.

The test was done at the Fetal Medicine Centre and the first follow-up scan (around 15 weeks)will take place there too just before Christmas. Apparently we get to see the big cheese himself - Professor Nicolaides - which surprised me.

I'll let you know how I get on