In Adoption of Michael H. (1995) 10 Cal.4th 1043, 1055 (Michael H.) the California Supreme Court emphasized that a biological father who wants to parent a child must make a timely commitment to undertake parental responsibility. The Michael H. court evaluated the extent to which an unwed, biological father could assert his constitutional rights under Kelsey S. to block an at-birth adoption under circumstances where he had agreed during the pregnancy that the baby should be placed for adoption. (Michael H., supra, at pp. 1047-1048, 1053.) In Michael H., during the first four months of the mother's pregnancy, the biological father supported the adoption choice. (Id. at p. 1053.) He thereafter changed his mind, but continued to speak to the mother and the prospective adoptive parents as though he still agreed to the adoption. (Ibid.) It was not until shortly after the baby was born that the father asked for custody and visitation rights. (Id. at pp. 1048- 1049, 1053.) Citing policy concerns arising from the mother's need to decide how to handle the pregnancy and receive assistance during the pregnancy, as well as the need not to create uncertainty for prospective adoptive parents, our Supreme Court held that because the father did not demonstrate his commitment to parenthood during the pregnancy, but rather waited until after the child's birth, he did not warrant Kelsey S. status. (Michael H., supra, at pp. 1055-1056.) The court concluded that in order to block the adoption, the father must show that "he promptly came forward and demonstrated a full commitment to his parental responsibilities as the biological mother allowed and the circumstances permitted within a short time after he learned or reasonably should have learned that the biological mother was pregnant with his child." (Id. at p. 1060.)