A friend of mine had a 1 in 10 risk of DS, as you can imagine she was pretty panicked but she had the Amnio and everything was fine so you could easily be too with that risk.
My risk with my last pg after the nuchal tests etc was 1:850 and the ob wanted me to have an amnio. I asked him the risk of losing a healthy pg because of an amnio and he said 1:400, I said I know which risk I would rather take thanks!

You need to weigh up the risks of whatever you decide to do and also make an informed decision about what you would do if it came back positive for downs.