Is a screening for Down's syndrome ...

(208 Posts)

MNHQ have commented on this thread.

KeepOnPloddingOn Sat 28-Jun-14 06:57:19

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.

Fevertree Sat 28-Jun-14 07:03:26

I thought 1:27 meant there would be 26
chances your baby doesn't have downs syndrome? Or am I being really thick?

Booboostoo Sat 28-Jun-14 07:10:46

The combined test is not a diagnostic, as in it does not tell you whether the baby has Downs syndrome or not, it is a statistical test, as in it gives you a probability the baby might have the condition. The test has a very small chance of a false negative and about 5% chance of a false positive. Either way the test is not positive, it says that there is a one in 27 chance of the condition, which also means a 26 in 27 chance of not having it.

Have you considered an amniocentesis? That is a diagnostic test but does carry a 1:250 chance of causing a miscarriage.

You may also want to ask for your post to be moved to a more suitable board where you will get more answers.

Poshsausage Sat 28-Jun-14 07:10:53

I think it is used alongside nuchal scan and further scanning for soft markers and a cvs if showing problems ? It's not just used on its own is it ?

Sorry just been through it but am a bit hazy on it all.we had hydrops showing and other problems the downs screening was the last and almost irrelevant result we had

Best of luck

kim147 Sat 28-Jun-14 07:17:16

It's a screening test - so they can not guarantee a yes / no answer. The probability of 1 in 27 puts you in the high category - are you having an amnio? I suppose the question is - do you want to know in advance and what would you do if the amnio was positive?

notoasthere Sat 28-Jun-14 07:21:07

It certainly isn't a given that your baby will have downs. The only way to know for sure is to have an amnio or cvs. The blood screening can be affected by so many different factors. Women should really be counsellors well before the test about what they would do if the result was to show a high risk

LoveBeingInTheSun Sat 28-Jun-14 07:28:40

After I very high result with ds I asked lots of questions on here and found stories of women who had been given high risk who went on to have children with out it however on there mext they had very low risk and had a child with ds.

Basically a one in 27 means, 1 woman in 27 with the same result will have a baby with ds.

I always wondered if high stress/depression affected my result and whether this was a true risk or if the stress/depression had actually had an effect on the baby

KeepOnPloddingOn Sat 28-Jun-14 07:31:42

Thanks everyone. I am well aware that 1:27 mean a 26 babies won't have it and one will according to their stats. But I am seeing a lot of people with downs kids saying that a high risk is a high risk regardless and it is very likely. They haven't explained why though. Hence why I am here smile

Sorry of I haven't explained this clearly. I have been up since 5 with my dd !

SimplyRedHead Sat 28-Jun-14 07:33:07

My baby's NF measurement was huge - can't remember the number but I think it was 6.3. His downs score was 1:3.

He doesn't have Downs. We also had a lot of specialist heart scans as a high NF measurement is often a sign of a whole in the heart but he's completely fine.

Good luck.

My bloods came back with a 1 in 11 chance of Downs for ds2. I had an amino and it came back all clear. So, the test is not certain, but those few days between getting the news and getting the results from the amino were the most worried I have ever been in my life.

x2boys Sat 28-Jun-14 07:37:31

I chose not to have any screening but my son was born not with downs but another rare chromosome disorder which I have since read ds screening may have shown some soft markers for this probably isn't what you want to hear and I hope all your tests come back completely normal .

I don't understand what a false positive could mean in a system that only gives you a ratio chance of 1 in 2 at the highest, however..... OP - this most definitely does not mean your dc is likely to have ds.

What it means is that based on whatever historical cases were used to build the algorithm, women with the same nuchal and blood results as you would have one ds child for every 27 born. Or to look at it another way you are believed to have about a 96% chance of your baby not having downs.

Look into harmony testing. We did it recently as I was given a 1:37 chance. It's non invasive so no risks of miscarriage; it's done on the mother's blood and has a 1:10, 000 chance of giving the wrong result.

It's offered in a few nhs hospitals but otherwise it is rather expensive I'm afraid.

Good luck - it's a horrible time but chances are very definitely in your favour!

AbiAbi Sat 28-Jun-14 07:40:53

DS had a reading of 1:65, so I know how terrifying it is.

We chose not to have any further tests, and just ride it out.

I read a lot about it, and there can be external factors upon the result. If you have been pregnant previously very soon before this pregnancy it can have an effect. Ditto bleeding in early pregnancy. There are others too. I will google.

Sorry you're going through this, it's agony isn't it. flowers

thobblywighs Sat 28-Jun-14 07:41:31

I had a result of 1 in 64. Didn't have an amino due to previous late miscarriage and DS didn't have Down syndrome. My friend had a result of 1 in 8 and did have an amino and that came back negative. I didn't have the test with DS2.

thobblywighs Sat 28-Jun-14 07:45:12

I chose not to have any screening but my son was born not with downs but another rare chromosome disorder which I have since read ds screening may have shown some soft markers for this probably isn't what you want to hear and I hope all your tests come back completely normal .

Interestingly, DS does have a chromosome disorder we have since found out whereas DS2, who had a number of soft markers on the 20 week scan, doesn't have it! 20 years ago we wouldn't have known about either of these!!

bruffin Sat 28-Jun-14 07:46:28

Dd was 1 in 60 and i had an amnio which came back clear. Dd does not have Downs

KeepOnPloddingOn Sat 28-Jun-14 07:46:38

Thanks everyone.
Abi- my dd is one so that makes sense. I have also had spotting...

lougle Sat 28-Jun-14 07:47:38

1:27 equates to a 3.7% chance of your baby having DS. which, of course, means a 96.3% chance that your baby does not have DS.

So no, it isn't highly likely that your baby has DS. Let's face it, if the National Lottery had a 96.3% success rate, we'd all queue up to pay!

Squiglettsmummy2bx Sat 28-Jun-14 07:49:20

My results were 1 in 250 & my son has Down syndromes he was that 1. Someone will have 1 in 2 but will not be the 1. Your baby has 26 chances not to be the 1 or 1 chance he or she will. Unless you have further testing you will not know for sure.

KeepOnPloddingOn Sat 28-Jun-14 07:50:09

Lou- haha, yes we would...

As I say, I have read a high result generally means a positive. But obviously what I have read is wrong given by everyone's responses on here anyway!

tobysmum77 Sat 28-Jun-14 07:52:26

As I understand it 1 in 27 is high risk but not as high risk as some people get.

There is a 26/27 chance of your baby but having downs but that's not the same as everything bring ok. There are other conditions which would lead to higher risk results which would also figure in the 26/27.

Therefore if you get a 1 in 2 then most of the time there will be something wrong. 1 in 27 however I doubt that is the case and it is far more likely to be a false positive. 2.1cm nuchal is also above average so would raise your risk without it actually being anything to worry about as such.

Are you having further testing op? Very worrying for you sad

KeepOnPloddingOn Sat 28-Jun-14 07:55:45

Toby- have cvs Monday smile will know by the end of the week. I didn't know 2.1 is higher than average :/

RunnerHasbeen Sat 28-Jun-14 08:07:03

If you are sampling people whose children were the 1 in 26 then of course they will say their risk translated to the condition. It doesn't make them wrong but what else are they going to say? If the tests were so wrong that 1/27 translated to a positive then we, as researchers, would adjust the scores to even higher. All the people you have spoken to have had their data added to the database and taking them into account gives you 1/27.

Glastokitty Sat 28-Jun-14 08:13:23

I had one in 11 with my son, had a cvs and he doesn't have downs. Like mrsdoylesteapot the wait for results was the longest few days ever. Good luck!

ikeaismylocal Sat 28-Jun-14 08:23:37

You are probably more likely to find stories from people who had 1/20 1/50 etc who did go on to have a diagnosis of down syndrome as it is relevant to their everyday lives, people who were in the 19/20 49/50 will probably not talk about their experience as often as it wasn't as relevant.

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