Well, because the test has no risks, other than the emotional risk of a false positive, I'm going to do it. With regard to a false positive, I believe that if the test is positive, they repeat it, thus reducing the chances of another false positive.
While I totally agree with the previous posting mamas, if I found out my angel would need me to become educated in ways I was not already, I'd like to get a jump start before she was even born. I would want to go ahead and join support groups/read books/etc. and be as ready as I could be to meet this child. I agree that they all need basically the same things in the beginning, but certain disorders may make those basic things (nursing, etc) more challenging, and I'd like to already KNOW what to do to give it all the best chance. Also, if there were going to be surgeries to make decisions regarding, I'd like to have more than a few months to become educated before it was time to give a decision.
My thought is, it can't hurt, but it could help.