In Adoption of Michael H. (1995) 10 Cal.4th 1043, the court considered more fully the question of what steps a biological father must take before a child's birth in order to veto a mother's plan for an at-birth adoption. In that case, the court held that "an unwed father has no federal constitutional right to withhold consent to an at-birth, third party adoption under our decision in Adoption of Kelsey S. (1992), unless he shows that he promptly came forward and demonstrated as full a 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." (Michael H., supra, 10 Cal.4th at p. 1060, ) The Supreme Court considered the situation of an unwed biological father who sought to prevent termination of his parental rights under Family Code section 7664. The court commented that under its decision in Adoption of Kelsey S. (1992), an unwed father can assert a federal constitutional right to withhold his consent to an at-birth third party adoption only if he has shown he promptly came forward and demonstrated full commitment to parental responsibilities as far as the mother and the circumstances would allow. ( Adoption of Michael H., supra, 10 Cal.4th at p. 1060.)