How is each part of downs test weighted?

[Newfamily2014]

Just wondering how each of the parts of the 12 week screening test: nuchal fold, maternal age, blood test etc is 'weighted'? Is most 'weight' put on the nuchal fluid measurement?
I know it's all added together but I have been worrying because I am 35 (34 when conceived) and know that the risk of abnormalities shoot up at 35. I had a normal scan today but will wait to tell people after I get my risk score, but I am so impatient and was just wondering if I could get a rough indication...
(I hope this makes sense!)

I'm sorry I don't know how all the tests results are worked out, but I just wanted to reassure you that your risk of downs is very low. Yes, it does rise (a bit) in your 30s but it is still much more likely that your baby won't have downs.
I had my first baby at 35 and I will give birth to my second when I am 38. My 'risk' this time was 1:65,000 so please try not to be too worried. If the nt measurement today was good then the odds should be in your favour.
All the best.

Thank you mayflower that was such a lovely message :-)
All the best for your pregnancy too!

I worried just like you - too much googling is not good! I also think there is a lot of scare mongering regarding having a baby in your 30s. I blame the dalily mail!

Forgot to say thanks for your good wishes!

I totally agree!! The Daily Mail has a lot to answer for! Coupled with pregnancy being a wonderful, yet worrisome time anyway!
Have you got long to go before your baby arrives?

I'm due in Jan. Time goes so slowly when you're pregnant ......

The Nt Test alone picks up 70% of cases of DS, adding in the bloods ups that to 95% so, quick bit of maths...!

70/95 * 100 = 73%
25/95 *100 = 26%

So the weighting of the combined test is (approx) 73% NT measurement, and 26% bloods.

Unsure about age etc, but the risk only really starts to shoot up at 35, the increase from 25-35 is still there, but not quite as dramatic...