You can certainly say that you wish not to parent children with FASD. The thing is, all of us have expressed certain behaviors, diagnoses, etc that we don't want. Sometimes we end up with them, anyway. Or worse. To a certain extent, it's a crapshoot, IMO.

If the children have been screened for FASD, and you have documentation of that, I would hope that it would be reliable. That doesn't mean that the diagnosticians might not miss a dx of RAD.

BTW, you will need to read the Special Needs thread, specifically FASD, to read all the very informative posts about this disorder. There are also many links that you may wish to check out. The issues thread doesn't have nearly the amount of information as Special Needs.