In my opinion everyone has the right to choose what is best for themselves, no government, no church, no other person has the right to tell you how to live your life.
As someone who was adopted, trust me, its not just the aids babies, or the drug babies or the FAS babies that are hard to place in good homes. A birth mother can take great care of herself and the baby can still have problems. Diabetes, Epilipse, CP, and any other number of diseases that can occur also affect placement. I was lucky. I'm diabetic (have been since birth too) and my parents still took me. How many sick kids aren't that lucky.
Now don't read this as "abort any fetus that might be sick" Believe me, I'm not saying that. All I'm saying is that all the choices that are available right now have downsides. Each woman, or rather couple (fathers shouldn't be left out of any decision, if at all possible) has to be allowed their choice.