Is a screening for Down's syndrome ...

[KeepOnPloddingOn]

Generally correct? I know occasionally there can be blips and false positives ... But generally is a high result a positive? I have a 1:27 chance of dc having downs. I have read conflicting info, but some say that getting such a high result generally suggests ds is inevitable - as the screenings are not 100% and a very high result should be taken as a highly likely.

I know this may sound confusing sorry, I am no expert on all this- I have been researching lots and as there are no answers as to why some Get such high results if baby doesn't have downs. So I am starting to believe it means in most cases a very high result such as mine is a 'more than likely' ...

For me it was my bloods giving me this high positive. The nt was 2.10- normal. I am mid twenties.

A result of 1:150 or less is considered high risk by the way. I think if I had a 1:100 it would be different - but our screening was relatively very high ...
Aibu to believe that thiS 1:27 Is not a diagnostic, but a pretty cert dc will have downs....? Any feedback would be appreciated.

I had a 1:27 result too. Had the amnio and no downs. There's still a high chance that your baby won't have downs.

Why do people stress so much about down syndrome? My daughter, who has a severe disability caused by NOTHING goes horse riding with a girl with down syndrome who is far more agile, intelligent, goes to a normal school and will leave and get a job, sees to all her personal care needs. Unlike my own daughter, who as I say has no testable syndrome at all, all tests clear.

Why does having a child with learning disabilities cause so much angst? Do you pass people like my family and feel pity for us? Because it's unnecessary. My daughter is a valuable member of society like all of you

I had a 1:13 risk of DS but my boy doesn't have it. Good luck for the CVS. The procedure itself is nothing to worry about.

Owllady - the demonization of DS by the medical system is interesting. There's a lot of discussion about it elsewhere.

None of my children have Downs Syndrome, but out of the three, I do have two with untestable conditions, one caused by birth injury. Life is pretty much a lottery.

Good luck on Monday, op xxx

I wasn't having a go at anyone by the way, I just find it a bit confusing when I feel we deal with far worse which has been described as 'one of those things'

I wish they wouldn't put so much pressure on women to have the whole perfect pregnancy, birth, child. Life isn't perfect or straightforward, but we all love our children (mainly)

I hope you can enjoy your pregnancy and have any worries dismissed very soon.

I don't remember any 1 in ? results for me but that may be because I didn't have any blood tests. My child's potential problems were picked up at the 20 week scan and I was asked if I had had the CVS test. Panic of course at this from me and scorn from the HCP when I refused an amnio and termination. The HCP were completely wrong about DC and I could have terminated a healthy baby if I had listened to them.

Always your baby, your choice as only you have to live with your choices. The HCP carry on and probably barely remember a lot of their patients.

A false positive relates to the fact that a 1:250 or higher result is considered positive, anything lower is considered negative. So about 5% of the positive results will be mistakes.

I admit I was stressed when we were told DS2 may have Downs Syndrome when I was pregnant.

Not because he could have simply had Downs Syndrome, but because of many things that are likely to come with that such as heart defects and other health issues.

I also worried about his future and who would care for him if he needed that when I couldn't any more.

The fact is people want to go to scans and hear 'Everything is fine'. Anything other than that is stressful.

owllady it is something that i have thought about a lot too. I had two pregnancies in my 40s and I felt like it was one of the major issues I was supposed to be thinking about. There are lots of posts on MN that give the risk of DS as a reason why older mothers shouldn't have children full.stop.

I just wrote a great long post but deleted it because I didn't want to hijack the thread.

Just want to be clear that I am not making any judgments about any women who have tests, don't have tests, have terminations or not.

Hi there,

We're going to be moving this thread to our Antenatal tests/choices topic shortly.

Thanks to everyone who has contributed so far.

I know that websites talk about 'false positives' but I'm not sure that makes sense as the test screens for risk rather than absolute diagnosis. Wouldn't the 1/27 risk indicate 26 'false positives' rather than 5%? Does anyone know what the 5% false positive thing actually means?

Pico - I have been pondering this too...

"A false positive relates to the fact that a 1:250 or higher result is considered positive, anything lower is considered negative"

Not at all. 1:250 is the cutoff point under which you get offered an amnio, because the risk is considered worthwhile. Nobody pretends when you get a 1:250 result (as I have) that you have had a positive test result.

"False positive" is a term used in tests that actually give a positive or negative result - i.e. you test positive for HIV although you don't have HIV. It has nothing to do with a test like the triple blood test that only gives a likelihood figure.

But even MN's guidance states 5% false positive of putting a foetus in a 'high-risk category' incorrectly here. What does it mean? Does it mean that in 5% of cases the scan measurement is inaccurate and the foetus actually has a 'normal' nuchal measurement? Because the other 95% don't seem to me to be actual positives at all, but might be read as such by concerned pregnant women. It's just confusing and probably leads to the type of question that the OP is asking.

Interestingly the NHS website doesn't talk about false positives at all, which is what I would expect.

I think people stress about DS because it can be screened for without risk to the foetus via a blood test/scan.

Sadly, I fear that it isn't DS people fear. It is disability. If people could screen for any disability and then terminate, many would. That saddens me -DD1 has the honour of going to school with some of the best people in the world.

Triple blood test is not the same thing as nuchal scan. Triple test gives a result like 1:27 or 1:250, not nuchal scan.

Re nuchal scan - My understanding is that it looks for markers that can strongly indicate a fetus with DS. It doesn't give a positive or a negative. You don't get told that your baby has DS, you only get told that you should have an amnio to know if your baby has DS. A nuchal translucency measurement above 3.5 mm is a strong indicator of not only DS but of other chromosomal abnormalities such as Trisomy 18.

Pico- when I asked doc about why some women have the hormonal correlation to suggest downs- when it actually isn't downs, she said they don't know.

No wonder people worry fgs...

I had a 1/100 result for my current pregnancy. It was because of my bloods too. I had amnio , and was all clear. That wasn't a 'false positive'. It was a 1/100 chance that I wouldn't get the all clear. a 99/100 chance I would get the result I did. But I needed to know.

I disagree with the idea that you should only have the tests if you would definitely terminate. There was actually a whole thread about this a while ago. I don't know for sure what we'd have done. But I know that, if I'd continued the pregnancy, I'd have prepared the children for a disabled sibling. I'd have pushed for a delivery where there were suitable specialists. I wouldn't have had a homebirth, probably pushed for a planned section. We were also clear that, if we had come back with a diagnosis incompatible with life (i.e. one of the other trisomies) we wouldn't have continued.

Penguin- we are going for the cvs for the exact same reasons as you.

Just realised I said 'current pregnancy'. DS is actually two months old! Should have said most recent pregnancy!!

I don't get this false positive thing either Pico. Just doesn't make sense with a risk based result.

I'm half with you Kim. All that seems to make sense although this result seems surprising and maybe will make more sense in the morning!

"So out of 464 people who test positive - only 9 will have the actual disease."

But I suppose what is not clear is what is counted as a "positive" in the downs combined screening test. You never get a positive, or a negative. The most "positive" result you can get is 1:2. You could surely classify that as positive (and therefore true positive if the child has the condition and false positive if they don't) or negative...