Confused by triple test result

[Tinkjon]

Hi there,
I got a letter today saying that I'm not at high-risk for Down's or Spina Bifida. I rang to get the actual number and it was 1 in 354 (last time was 1 in 3900!) but my age-related risk was 1 in 181. I know the cut-off point is 1 in 250, so how can I be low-risk with an age-related result of 181? Do they just ignore the age result and only go by the first one? Being in the 300s seems an awful lot of difference to my last result of 3000s :-/ I rang my GP to ask but they weren't very helpful. Any thoughts anyone?
Thanks!

Percentage-wise, 1/181 is a little more than half a percent - which is very low risk. I know it's higher than, and therefore sounds worse than, 1 in 3900 but it's still very low.

The age related result is the same for every woman of your age. Now that they have done the triple test they have taken the result of that and you age into account and come up with 1:354. so you are about half as likely as the average woman of your age to have a baby with Downs. if you are now over 35 the age related risk increases steeply so it is harder to get a result in the thousands. If you phone your antenatal clinic where they did the test they should be able to give you more information if you want it

Thanks so much, that makes complete sense! Funny how a GP can't explain this but a mumsnetter can Much appreciated!