It’s still an open question. The general feeling is that it might encourage abortion by making people feel that their “extra” embryos will be adopted. At the same time, the fact is that adopting these embryos does save the lives of these babies.
My daughter has been looking into this and we have done a fair amount of research on it.
I don’t understand how the church can be against embryo adoption. I understand their concern, but their position should be quite clear. If life begins at conception (it does) then embryo adoption should be considered no different than adoption after birth. No one says that the practice of adoption encourages people to get pregnant unnecessarily, and the church is very supportive of the adoption practice. How can the adoption of an embryo be any different?