triple test results difference between 1st and 2nd pg - can anyone explain?

[mabel1973]

HI

I have just had my triple test results back. The results sheet explains that for my age (33 in may) I have a 1 in 590 chance, however combined with my bloods this brings it down to 1 in 470. I know this is still good odds, but when I had DS ( I was 31 when I had him) my results were the equivalent of something a 15 year old would get (1 in over a 1000).
I guess I am concerned about the vast difference bewteen the results and what factors can cause this. Can anyone explain this for me?

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I know your risk rises with age but your bloods are a major factor too.

Info found online:

Low maternal serum alpha-fetoprotein (MSAFP), elevated human chorionic gonadotropin (hCG) and low unconjugated oestriol are markers for Down's syndrome and form the basis of the antenatal triple test which should be particularly offered to at risk (ie older) mothers

What are the risks of Down's syndrome?

On average, one in every 1,000 babies born in the UK will have Down's syndrome. The risk increases with the mother's age, particularly after 35, as shown in the list below.1

At 25 years old the risk ratio is 1 in 1400.

At 30 years old the risk ratio is 1 in 800.

At 35 years old the risk ratio is 1 in 380.

At 38 years old the risk ratio is 1 in 190.

At 40 years old the risk ratio is 1 in 110.

At 45 years old the risk ratio is 1 in 30.

As well as your age, you can get different results depending on your weight and whether you are further along or less far along in your pregnancy than was thought.

I havent had my triple test yet but hope the result will be good. take care.

Thanks Seona
do you have the link to that information?

\link{http://www.womens-health.co.uk/downs.asp\womens health}

and \link{http://www.netdoctor.co.uk/health_advice/facts/pregnancy_testing_time_000617.htm\net doctor}

I just googled 'triple test downs' and looked up a couple of the sites that came up. There were quite a few more if you want to check it out.

The chemicals that are measured are produced by the baby (and placenta etc) not by you. So this baby is producing different concentrations of chemicals than your last baby, which is why the risk is so different.

The only thing that is provided by you is the age of the egg - which in this case is 2 years older - the increase in risk due to increased maternal age is not a proportional relationship - the risk slowly rises to about age 30 then it starts to increase rapidly (as Seona's)

Sorry, hit post accidently.

meant to say....as Seona's post shows.

Hi Mabel - I had DS when I was 36 and had a perfectly fine Nuchal scan and then had a triple test - terrible result - got a huge fright but was lucky enough to be able to have a consultation with Dr Kypros Nickolaides in London - Google him if you are interested - anyway - he called me a neurotic old woman for having the triple test in the first place and then told me that if he had his way he would ban the triple test all together! (That's how useless he thinks it is) Basically it measures only one hormone when, in actual fact, you need a combination of hormone measurements to get a true risk assessment - so what blubear said is absolutely spot on -
Kypros also told me that we are way too obssessed with the "age" thing - it's not like your body goes from being 34 years and 364 days old to the next day and suddenly knowing that now something is different. another analogy that I liked was the story about night creams - I mean, how does the cream know that it's night so must now work? why not use a night cream during the day? - IYSWIM
BTW - have a beautiful healthy baby boy.
Let me know if you want to know more aobut what Kypros told me - will happily send you the rest of what he said - none of which was complimentary about the triple test BTW.

Thanks coolmama - I have read up a little bit and did find a bbc report saying that it was thought to be a waste of money. I honestly wished I'd not had it done. After last time I was so anxious during the wait then it came back fine, I suppose I just expected to get a similar result this time and it was a bit of a shock when it came back at a much higher risk.
If you know a link where I can read up any more that would be useful, but in the mean time I think I am going to just wait til my 20 week scan and hope that it gives me some more detailed info.

Hi im 37 and 17 weeks preg. I never took the t/test as i thought if the outcome was negative i would be unable to take any further steps anyhow. Now i have worried if i have done the right thing and should i have taken the test anyhow? Just giving myself more worry about not taking a worring test! Isnt pregnancy a great thing?

I really don't think you should worry about not having taken the test - the important thing is to relax and enjoy your pregnancy!

If the triple test isn't very reliable, if it was skipped, does anyone know, would any abnormalities (perish the thought!) be detected at the 20 week scan?

The more obvious abnormalities associated with Down syndrome would be - like heart defects and some bowel problems, but some babies with Down syndrome would not have any abnormalities that can be seen by scan.

Before the maternal blood test was available, definitive testing (by amniocentesis or chorionic villus testing) was only available to mothers over the age of 35 or to those with abnormalities seen at the 20 week anomaly scan - this picked up 30% of babies with Down syndrome.
The triple/quad test will pick up 60% of babies with Down syndrome (so will give a 'low risk' result for 40% of affected babies).
The nuchal fold test also picks up 60%, but if you have nuchal fold plus nasal bone it supposedly picks up 85% (so still misses 15%) - this was pioneered by Nicolaides so he's going to say it's the best - but it's only available in specialist units that have trained ultrasonographer and fantastically good ultrasound machines.
Other combinations of blood tests, plus nuchal fold scans will pick up about 80%.
All of the stats above are used with the same 'cut-off' point ie. most of the babies that are identified as at high risk of DS are in fact normal.
The only test that cuts down on the number of tests that are given a 'high risk' result whilst picking up 80% of DS babies is the combined test pioneered by Nick Wald - it involves combining a blood test and nuchal scan at about 12 weeks with another blood test at 16 weeks so it's a hassle and you have to wait til about 17 weeks for your result. (I had this test when pg with dd).
Have I bored you all now :)

I guess the most important thing to understand about all these scan + blood tests is that they give you a "risk assessment" (ie not definite) which is supposed to be of help in deciding if you want or need to have an amnio or CVS - So that needs to be kept in mind when contemplating having these scans - the only definitive tests are the two invasive ones and, on a personal note, I would have to have a really good reason for having one of those.

I have heard alot about DS, but my #s came back with an elevated risk of trisomy 18...1/120...I have 2 healthy children, but since I'm 36 my Dr. recommends the amnio, because of the elevated risk??? I don't know what to do??? What do you think???

syd I have a little girl with down syndrome and we knew before she was born that she would be born with a serious but operable heart defect and if she did not have down syndrome - it would be very very rare.
Her heart defect is very very common in children with down syndrome.

WHen they found the heart defect - at Harris birthright trust where Prof Kyriades is - we were offered an amnio. Dh and I said no - mainly because we knew the outcome of the amnio would not change anything. We were going to have our baby.

We then when pregnant with dd2 - they picked up a soft marker for down syndrome and again we were offered an amnio - we refused again simply because it would not have changed the outcome and therefore saw it as an unnecessary procedure. I was 35 - 36 when pregnant with dd2.

I think you need to decide what you need to know - that is whether you need to know for certain and if you would act on that information in some way. You also need to consider the risk of miscarriage versus the risk of having a child with trisomy 18.

No one can tell you one way or the other what to do - but for me it was the decision about the outcome was important in determining whether to have an amnio or not. I guess you just have to work out what is best for you in your situation.

hope that is a help.

Hi. When I had my first child 3 years ago (age 31), my results from the triple test were something like 1:6000. However, I am now 22 weeks pregnant with my second (age 34) and my triple test at 16 weeks came back 1:50 for downs. After a lot of researching on the internet and postings on mumsnet, I had an amnio and found out everything OK. It really depends on a number of factors; age, weight, blood group, etc.