Agreed Peapod, the risk can result in a big reward, but the risks are huge. Not only drug addiction, but Fetal Alcohol syndrome can be also difficult to diagnose in a baby. I used to volunteer at a childrens group home, and some of those children were afflicted with this, and they were extremely difficult to handle, violent etc.
Then there's the issue of raising an ethnic child for a lot of people, not to mention the difficulty for the child as he/she reaches school age etc.
Issues that can be overhelming for most people, hence why we do not see as many public adoptions of kids in the system.
While I volunteered for this agency, I became attached to an African American boy about 8. We considered the possibility of adopting him had his Aunt not come forward to do so, but I do not think I would have ever considered adopting any of the other children he was housed with due to the above reasons.