Actually, this is not the case. In extremely early gestation, in the case of "test tube" fertilization, embryos are frozen and kept in case earlier implantation into the mother's womb are unsuccessful. Most of the time, the implantation works, leaving embryos in waiting. In these cases the choice of some of these mothers is life for the embryos, leading to the adoption process beginning. A friend of mine adopted several of these embryos, two of which successfully thawed and were implanted into her womb. One survived to term and is now a toddler. Before this adoption, though, the couple had contact with a birth mother who indeed had changed her mind. It is indeed "relevant."