OP, I'll say it again: you really, really need to consult with an attorney. If your jurisdiction's rules for artificial insemination with adoption are not followed correctly, you could be facing some nasty surprises and legal headaches down the road.
There was a famous case in New York [Thomas S. v. Robin Y., 209 A.D.2d 298 (N.Y. App. Div. 1994)] where a sperm donor to a lesbian couple initially asserted he wanted no parental rights or responsibilities, but the couple agreed that the child would know her birthfather when she was old enough. When the child was three, he began to develop a close relationship with her -- frequent visits, letters, gifts, etc. Then he requested to take the child to meet his own parents; the couple balked and cut off contact. There was a lengthy court battle, with the state Supreme Court eventually awarding him standing as the father. The lesbian couple announced their intent to appeal, and he ultimately dropped his application for paternity. This was 13 years after he agreed to be the donor.
Make certain you understand the legal ramifications before the child is born.