If I were you I would think about what you would do if the amnio results came back not so good. Would you terminate? Or would you carry on with the pregnancy and take the risk?

If its the latter, then I wouldn't do the amnio. But thats just me and I wouldn't terminate anyway.
That is exactly what I was going to say. But then again like someone said, the peace of mind would be good.

If you look at it realistically though, the chances of miscarrying from the amnio are higher than the risk of Downs.

Whatever you choose will be right for you.