Opinion
MOSK, J.In this appeal we further clarify the circumstances (see Adoption of Kelsey S. (1992) 1 Cal.4th 816 [4 Cal.Rptr.2d 615, 823 P.2d 1216] (hereafter Kelsey S.)) in which an unwed biological father has a right under the due process and equal protection clauses of the Fourteenth Amendment to withhold his consent to the biological mother’s decision to give their child up at birth for adoption by a third party. We are also asked to consider whether an unwed father can be equitably estopped from attempting to veto such an adoption on constitutional grounds, whether an unwed father is barred as a matter of law from asserting such a veto if he was over age 18 and the mother was under age 18 at the time of conception, and whether children have a Fourteenth Amendment liberty interest in the continuity and stability of their family lives that limits their unwed father’s ability to exercise his own Fourteenth Amendment right to veto the adoption.
We conclude that the unwed father in this case did not satisfy the requirements of Kelsey S. as they are properly understood, and hence that he *1048has no constitutional right to veto his child’s adoption. The judgment of the Court of Appeal to the contrary must therefore be reversed. In light of this holding, we need not and do not consider the parties’ contentions regarding equitable estoppel, the ages of the biological parents at the time of conception, and the interests of children in the stability and continuity of their family lives.
Facts
Stephanie H. met Mark K. in December 1988 in Arizona. In February 1990, Mark, then age 20, told Stephanie, then age 15, that he wanted to marry her. She declined to get married until she graduated from high school and until he quit drinking and using drugs. However, they considered themselves engaged at that time. In early July 1990 Stephanie learned she was pregnant with Mark’s child. Mark suggested that she have an abortion, but she would not consider it. They also briefly discussed keeping the baby, but finally settled on adoption.
Stephanie came to California with her grandparents in July 1990. While here her aunt introduced her to two friends, John and Margaret S., who were interested in adopting a child. Stephanie told Mark about John and Margaret when she returned to Arizona at the end of July 1990. Around that time Stephanie and Mark were also researching adoption agencies.
In September 1990 Mark and Stephanie began attending birthing classes together, and Mark went to at least one yard sale with Stephanie to buy baby apparel. He also bought a trailer for them to live in together, although they never did. In early October 1990 Mark arranged to have a videotape of Stephanie’s ultrasound made.
Mark and Stephanie’s relationship started to deteriorate around this time. Stephanie excluded him from the birthing classes. Mark had two violent outbursts involving Stephanie, and after one of these he was arrested on a charge of aggravated assault. Mark quit his job on October 26, 1990. Two days later, on Stephanie’s 16th birthday, Mark went into his trailer, which was parked behind Stephanie’s mother’s house, and attempted to kill himself.
After his suicide attempt, Mark admitted himself into a rehabilitation hospital. While there he decided to stop using drugs, seek stable employment and residence, and continue counseling. He also decided that he did not want to give up his child for adoption and started looking for an attorney to help him obtain custody after the child was born.
*1049Mark and Stephanie had very little contact after his suicide attempt. In January 1991 Stephanie moved from Arizona to San Diego to live with John and Margaret. She gave birth to Michael H. on February 27, 1991. Michael was released from the hospital directly into John and Margaret’s custody, where he has remained ever since.
On March 7, 1991, Mark found an attorney who would take his case free of charge. That day his attorney telephoned John and Margaret and learned that Michael had been born. As soon as he found out, Mark asked for custody, sent out some birth announcements, and bought several items, including a car seat, a crib, and some baby clothes.
In April 1991 John and Margaret filed a petition to terminate Mark’s legal status as Michael’s father. (Fam. Code, § 7662.)1 Mark subsequently filed a petition to establish a father-child relationship (§ 7630, subd. (a)(1)), and the two proceedings were consolidated (id.., subd. (c)). The court concluded that Mark was not a “presumed father” under the statutory definition (§ 7611) and that it would be in Michael’s best interest to be adopted by John and Margaret (§ 7664, subd. (b)). It therefore terminated Mark’s parental status and allowed the adoption to proceed.
While Mark’s appeal from that judgment was pending we filed our decision in Kelsey S., supra, 1 Cal.4th 816, in which a majority held that under certain circumstances unwed fathers have a Fourteenth Amendment right to prevent third parties from adopting their biological children. John and Margaret contended, on the basis of certain dicta in that decision, that Mark had no such right because he was over age 18 and Stephanie was under age 18 at the time of conception. The Court of Appeal rejected that contention but reversed the judgment with directions to the trial court to hold an evidentiary hearing on whether Mark had a constitutional right to veto Michael’s adoption under Kelsey S.
None of the parties petitioned this court for review, but John and Margaret requested that we order the opinion unpublished on the ground that the Court of Appeal erred in rejecting their contention regarding Mark’s and Stephanie’s ages at the time of conception. (Cal. Rules of Court, rule 979.) We granted their request.
1After holding an evidentiary hearing on remand, the trial court concluded in light of our decision in Kelsey S. that Mark had a constitutional right to *1050veto Michael’s adoption absent a showing that he would be an unfit parent. John and Margaret noticed an appeal.2
The Court of Appeal affirmed the trial court’s decision. It rejected John and Margaret’s contentions that the trial court misinterpreted our holding in Kelsey S., that under the correct legal standard there was insufficient evidence to support the decision, and that Mark was equitably estopped from attempting to assert a constitutional right to veto the adoption. The Court of Appeal declined to consider whether Michael had a Fourteenth Amendment liberty interest in the stability and continuity of his family life with John and Margaret, both because the trial court had not considered the issue and because it was not necessary to the decision. We granted review.
Discussion
I.
There has been some confusion in the lower courts and among the parties in this case regarding the relationship between the two distinct but closely interwoven sources of law that govern the rights and duties of unwed fathers in adoption proceedings—California’s statutory scheme and the Fourteenth Amendment to the federal Constitution. To allay this confusion and to place the issues in their proper context, we begin with an overview of these two bodies of law insofar as relevant.
Much of the statutory law governing this case is derived from the Uniform Parentage Act of 1973 (UPA), adopted by our Legislature as section 7600 et seq. of the new Family Code. (See § 7600.) “The UPA provides a comprehensive scheme for judicial determination of paternity, and was intended to rationalize procedure, to eliminate constitutional infirmities in then existing state law, and to improve state systems of support enforcement.” (Michael M. v. Giovanna F. (1992) 5 Cal.App.4th 1272, 1278 [7 Cal.Rptr.2d 460]; 9B West’s U. Laws Ann. (1987) U. Parentage Act, comrs. note, pp. 287-290; Legis. Counsel’s Dig., Sen. Bill No. 347, 2 Stats. 1975 (Reg. Sess.) Summary Dig., p. 344.)
An unwed father’s rights and duties under the UPA substantially depend on whether he is a “presumed father” within the meaning of section *10517611. (Kelsey S., supra, 1 Cal.4th 816, 823 [“Whether a biological father is a ‘presumed father’ ... is critical to his parental rights [in adoption proceedings].”]; see also In re Zacharia D. (1993) 6 Cal.4th 435, 448-449 [24 Cal.Rptr.2d 751, 862 P.2d 751] [only “presumed fathers” are entitled to custody and reunification services].) Under section 7611, a man who has neither legally married nor attempted to legally marry the mother of his child cannot become a presumed father unless he both “receives the child into his home and openly holds out the child as his natural child.” (§ 7611, subd. (d), italics added.) We recently rejected an unwed father’s contention that a man can constructively receive a child into his home within the meaning of this statute. (Kelsey S., supra, 1 Cal.4th at pp. 825-830.) Therefore, to become a presumed father, a man who has neither married nor attempted to marry his child’s biological mother must not only openly and publicly admit paternity, but must also physically bring the child into his home.
If a man is a presumed father, a third party generally cannot adopt his child unless both he and the mother consent. (§§ 8604-8606.) If a man is not a presumed father, however, the situation is quite different. The mother’s consent is still required in most cases (ibid,.), but the father’s consent is not required unless he successfully petitions to block the adoption and establish his legal status as the child’s father. (§§ 7630, 7662.) Even if he files such a petition, the adoption will proceed over his objection if either the mother or the party seeking to adopt the child successfully petitions for termination of his parental status. (§ 7662.)
If the court finds in such a proceeding that “it is in the best interest of the child that the father retain his parental rights,” it must enter an order providing that his consent is necessary for an adoption. (§ 7664, subd. (b).) In making this determination, the court “may consider all relevant evidence, including the efforts made by the father to obtain custody, the age and prior placement of the child, and the effects of a change of placement on the child.” (Ibid.) If, however, the court finds that it is in the best interest of the child to be adopted by the prospective adoptive parents, it must enter an order stating that the father’s consent is not required. (Ibid.) This order also “terminates all [the father’s] parental rights and responsibilities with respect to the child.” (Ibid.)
In essence, therefore, our statutory scheme creates three classes of parents: mothers, fathers who are presumed fathers, and fathers who are not presumed fathers. (Kelsey S., supra, 1 Cal.4th 816, 825.) Parents belonging to either the first or second class usually have a statutory right to veto adoption by withholding consent regardless of what the court believes to be the child’s best interest. (Ibid.) However, a biological father who is not a *1052presumed father has no statutory right to block adoption unless he first proves that it is in the child’s best interest that the adoption not proceed. (Ibid.) As we noted in Kelsey S. (id. at p. 824), “the trial court’s determination is frequently that the child’s interests are better served by a third party adoption than by granting custody to the unwed natural father.” (Fn. omitted.)
Here the trial court determined at the first hearing that Mark is not a presumed father under the statutory definition (§ 7611) and that it would be in Michael’s best interest to be adopted by John and Margaret (§7664). Mark does not contend these conclusions were erroneous. It follows that Mark has no statutory right to withhold consent to Michael’s adoption. However, both the trial court and the Court of Appeal concluded that although Mark has no statutory right to block adoption by withholding consent, he has a constitutional right under Kelsey S., supra, 1 Cal.4th 816, to prevent Michael’s adoption and to establish his legal status as Michael’s father unless John and Margaret prove that he would be an unfit parent. The only issue before us is whether that conclusion is correct.
II.
We held in Kelsey S., supra, 1 Cal.4th 816, that an unwed father who has no statutory right to block a third party adoption by withholding consent may nevertheless have a constitutional right to do so under the due process and equal protection clauses of the Fourteenth Amendment and thereby to preserve his opportunity to develop a parental relationship with his child. Under such circumstances, however, the unwed father’s constitutional interest is merely inchoate (Lehr v. Robertson (1983) 463 U.S. 248, 261-263 [77 L.Ed.2d 614, 626-628, 103 S.Ct. 2985]) and does not ripen into a constitutional right that he can assert to prevent adoption unless he proves that he has “promptly come[] forward and demonstrate^ a full commitment to his parental responsibilities . . . .” (Kelsey S., supra, 1 Cal.4th 816, 849.) This is so because “the mere existence of a biological link does not merit . . . constitutional protection” (Lehr v. Robertson, supra, 463 U.S. at p. 261 [77 L.Ed.2d at p. 626]); rather, the federal Constitution protects only the parental relationship that the unwed father has actively developed by “ ‘com[ing] forward to participate in the rearing of his child’ ” (ibid.) and “act[ing] as a father” (Caban v. Mohammed (1979) 441 U.S. 380, 389, fn. 7 [60 L.Ed.2d 297, 305, 99 S.Ct. 1760]).
We must decide whether Mark took sufficient steps to transform his inchoate constitutional interest in his potential parental relationship with Michael into a constitutional right that entitled him to block John and *1053Margaret’s efforts to adopt Michael and terminate his status as Michael’s father. Our task is made more difficult by the circumstance that here the adoption process began at birth and Michael has been in John and Margaret’s custody and care for all of the more than four years of his life. Mark has therefore had little contact with Michael and little opportunity to directly develop a parental relationship with him, and Michael instead experiences only John and Margaret as his parents.
After its hearing devoted to the question whether Mark was entitled to constitutional protection under Kelsey S., the trial court prepared a rather lengthy summary of its findings. In this summary the court declared that during the period between early July 1990, when Mark first learned that Stephanie was pregnant, and October 28, 1990, the day he attempted suicide, “it cannot be said that he was fully committed to his parental responsibilities. While he always acknowledged his paternity, he clearly planned with Stephanie to give the child up. Like many fathers (and mothers) he was initially frightened and eagerly looked for a way out of these responsibilities.” During his hospitalization in November 1990, Mark “decided he did not want his child given up for adoption.” Despite this decision, however, Mark continued to “speak to Stephanie and even [John and Margaret] as though he still agreed with the adoption” until March 7, 1991, some two weeks after Michael was born, because, according to Mark’s testimony, “he did not want to risk the sort of polarization which might totally close the door to further communication.”
The trial court found that “After his release from the hospital, and particularly after the birth of his son, Mark’s efforts were nothing short of impressive,”3 and “In the two years since his son’s birth, Mark has never wavered in expressing his desire to take on the full responsibility of fatherhood.” The court also noted that each of Mark’s three attorneys testified that Mark “incessantly, relentlessly urged” them to seek visitation rights. In light of these findings, the court concluded that Mark’s “struggle before his hospitalization and the subsequent birth of his son does not counterbalance his truly extraordinary efforts and commitment afterward,” and that “In the context of all the facts of this case, his efforts sufficiently demonstrate his full commitment to his parental responsibilities” within the meaning of Kelsey S.
*1054The Court of Appeal held among other things that the trial court had correctly interpreted our decision in Kelsey S. as creating a “balancing test,” under which courts must weigh “all factors against each other. . . weighing positives against negatives to arrive at a determination whether a father ‘demonstrated the necessary commitment to his parental responsibilities’ ” “over the whole course of the proceedings.” The Court of Appeal then held there was ample evidence to support the trial court’s decision under this standard.
III.
John and Margaret contend that the trial court and Court of Appeal misinterpreted and misapplied our decision in Kelsey S., supra, 1 Cal.4th 816, and that under the correct standard the trial court’s findings do not support its decision that Mark “promptly [came] forward and demonstrate^] a full commitment to his parental responsibilities” and was therefore entitled to constitutional protection. (Id. at p. 849.) They focus on that portion of Kelsey S. in which we stated that in deciding whether an unwed father is entitled to constitutional protection, “A court should consider all factors relevant to that determination. The father’s conduct both before and after the child’s birth must be considered. Once the father knows or reasonably should know of the pregnancy, he must promptly attempt to assume his parental responsibilities as fully as the mother will allow and the circumstances permit. In particular, the father must demonstrate ‘a willingness himself to assume full custody of the child—not merely to block adoption by others.’ [Citation.] A court should also consider the father’s public acknowledgment of paternity, payment of pregnancy and birth expenses commensurate with his ability to do so, and prompt legal action to seek custody of the child.” (Ibid., italics in original, fn. omitted.)
John and Margaret rightly concede that the quoted language does not mean that an unwed father must continually express an unequivocal desire to raise his child from the very moment he learns of the pregnancy or that he can never take a minute to reflect on the importance of his decision and the responsibilities that will come with it. Rather, they contend that although all the unwed father’s conduct is relevant and important, he has no constitutional right to withhold his consent to an at-birth, third party adoption under Kelsey S. unless he “promptly” demonstrated a “full commitment” to parenthood during pregnancy and within a short time after he discovered or reasonably should have discovered that the biological mother was pregnant with his child, and that he cannot compensate for his failure to do so by attempting to assume his parental responsibilities many months after learning of the pregnancy.
*1055We agree with John and Margaret’s reading of the quoted language. It is difficult to conceive how our statement that “Once the father knows or reasonably should know of the pregnancy, he must promptly attempt to assume his parental responsibilities as fully as the mother will allow and the circumstances permit” (Kelsey S., supra, 1 Cal.4th at p. 849) could be read in any other way. To construe it as Mark does destroys the mandatory force of the word “must” and makes the word “promptly” meaningless. Such a conclusion is particularly inappropriate in view of the fact that we also stressed the importance of timely action both in the paragraph preceding and in the paragraph following the quoted language. In the former we stated that “If an unwed father promptly comes forward and demonstrates a full commitment to his parental responsibilities—emotional, financial, and otherwise—his federal constitutional right to due process prohibits the termination of his paternal relationship absent a showing of his unfitness as a parent.” (Ibid.., italics added.) In the latter paragraph we stated that “The statutory distinction between natural fathers and presumed fathers is constitutionally invalid only to the extent it is applied to an unwed father who has sufficiently and timely demonstrated a full commitment to his parental responsibilities. Our statutes [citations] are constitutionally sufficient when applied to a father who has failed to make such a showing.” (Id. at pp. 849-850, italics added and deleted.) John and Margaret’s reading of Kelsey S. is not only correct, but virtually inescapable.
John and Margaret also contend their reading of Kelsey S. serves several important public policy goals. We find their points persuasive. They first assert that an unwed father should be encouraged to promptly inform the biological mother during pregnancy whether he objects or consents to the child’s adoption at birth, and that he should be denied constitutional protection after birth if he concealed his views during pregnancy. They stress that during pregnancy the mother must make many important decisions, most importantly whether to have an abortion, to prepare an adoption plan, or to keep the baby, and that she has only a relatively short time to make and implement her choice. It is therefore important that the father give the mother prompt notice whether he plans to object or consent to adoption so that she can evaluate that and other options on an informed basis.
John and Margaret also point out that the mother may well need emotional, financial, medical, or other assistance during pregnancy, particularly if she, like Stephanie, is a teenager. It can scarcely be disputed that prenatal care is critically important to both the mother and the child. (See, e.g., Matter of Adoption of Doe (Fla. 1989) 543 So.2d 741, 749 [“Congress [has] found . . . [that] substantial numbers of pregnant women and unborn children are placed at special risk with respect to physical and mental health by *1056inadequate nutritional or health care.”]; In Interest of Baby Girl K. (1983) 113 Wis.2d 429 [335 N.W.2d 846, 851] [“Medical authorities have long recognized that prenatal care is important to the eventual health and well-being of an infant.”].) To the extent the mother needs such critical assistance and the unwed father is able to provide it, the father, as one of the two individuals responsible for the pregnancy, should be encouraged to do so early on and should not be granted constitutional protection after birth if he has failed to timely fulfill this responsibility. Indeed, if unwed fathers are not encouraged to provide prenatal assistance when they are able to do so, the burden will often shift to the state and therefore to society generally. (Matter of Adoption of Doe, supra, 543 So.2d 741, 749 [“The failure of unwed fathers to provide support during pregnancy is certainly a major factor in this public problem and transfers the burden to society at large . . . .”].)
Furthermore, if an unwed father is permitted to ignore his parental role during pregnancy but claim it after birth, it will often be very difficult to know with certainty whether he will be able to successfully contest an adoption until after the child is born. This uncertainty could well dissuade prospective adoptive parents from attempting to adopt the children of unwed mothers who, like Stephanie, have chosen for whatever reason not to keep their child and raise it themselves. And that result would frustrate the state’s clear interest in encouraging such adoptions and providing stable homes for children. (See Kelsey S., supra, 1 Cal.4th 816, 844 [“There is no dispute that ‘The State’s interest in providing for the well-being of illegitimate children is an important one.’ ”]; Robert O. v. Russell K. (1992) 173 A.D.2d 30 [578 N.Y.S.2d 594, 597] [“without the requirement that the unwed father manifest his interest promptly, parties to an adoption proceeding would have no assurance that an adoption was permanent. Such uncertainty would undermine the State’s recognized interest in facilitating sure and speedy adoptions and providing permanent, stable homes for adopted children . . . .”].) The state’s interest in this matter is particularly important in light of the large number of children born to unwed parents: some 25 percent of all children born in the United States between July 1989 and July 1990—approximately 913,000 out of 3,900,000—were born out of wedlock. (Kelsey S., supra, 1 Cal.4th at p. 830, fn. 6.)
John and Margaret also contend that an adopted child may suffer emotional damage if the unwed father conceals his objection to a third party adoption during pregnancy and the adoptive parents take custody at birth in reliance on the unwed father’s apparent consent, but the unwed father then initiates often lengthy legal proceedings after birth in an effort to derail the adoption and remove the child from the adoptive parents’ custody. If such an unwed father is allowed to prevail after perhaps years of litigation, during *1057which time the child will likely come to see the adoptive parents as his “true” parents, the resulting disruption in familial relationships and living arrangements can have a very damaging impact on the child’s psychological growth and development.
Experts in child development agree with John and Margaret on this point. In the words of one authoritative treatise on the subject, “Continuity of relationships, surroundings, and environmental influence are essential for a child’s normal development.” (Goldstein et al., Beyond the Best Interests of the Child (1979) p. 31.) Indeed, we have recognized the harm that children may suffer when they are separated from those they have come to identify as their parents. (In re Baby Girl M. (1984) 37 Cal.3d 65, 76, fn. 12 [207 Cal.Rptr. 309, 688 P.2d 918] [when a child remains in the custody of the prospective adoptive parents pending the outcome of protracted litigation, “strong relationships . . . develop [], and breaking those bonds could be harmful to the child”].)
The United States Supreme Court has also recognized this problem. (Stanley v. Illinois (1972) 405 U.S. 645, 647 [31 L.Ed.2d 551, 556, 92 S.Ct. 1208] [when children are removed from their usual environment they “suffer from uncertainty and dislocation” even if they are later returned to it, and therefore even temporary disruptions can be detrimental].) And many courts in other states have emphasized the importance of stability and continuity in a child’s family life and the harm often caused by drastic changes. (See, e.g., Matter of Kailee C.C. (1992) 179 A.D.2d 891 [579 N.Y.S.2d 191, 192] [“Bearing in mind a child’s need for early permanence and stability, the key to the unwed biological father’s constitutional right to consent to the adoption is the prompt assertion of his interest and a manifestation of his ability and willingness to assume custody of the child . . . .”]; Matter of Adoption of Baby Boy D. (Okla. 1985) 742 P.2d 1059, 1067-1068 [“Children are not static objects. They grow and develop, and their growth and development require more than day-to-day satisfaction of their physical needs. . . . [¶] This court recognizes that a child’s need for permanence and stability, like his or her other needs, cannot be postponed. . . . The need for early assurance of permanence and stability is [therefore] an essential factor in a constitutional determination ... of whether or not to protect [an unwed father’s] potential relationship with his child.”].)
Lastly, there can also be little doubt that “the . . . adoptive parents suffer emotionally if the child is separated from them after a prolonged period.” (Allen, Adoption of Kelsey S.: When Does an Unwed Father Know Best? (1993) 24 Pacific L.J. 1633, 1678; see also In re Baby Girl Eason (1987) 257 Ga. 292 [358 S.E.2d 459, 460] [one of the “competing interests of overwhelming value” in cases addressing an unwed father’s federal constitutional *1058right to veto adoption is the interest of the prospective adoptive parents, who often “have developed strong emotional connections through their custody of the child, beginning very soon after birth, [and therefore] have interests they likely value beyond measure”].) It would seem inequitable to give preference to an unwed father who failed to fully grasp his parental obligations in a timely fashion over prospective adoptive parents who have made a significant and continuing effort, both before and after birth, to discharge the responsibilities of parenthood.
In similar circumstances our sister states have likewise insisted that unwed fathers must assume their parental responsibilities promptly during pregnancy. (See, e.g., Matter of Adoption of Doe, supra, 543 So.2d 741, 749 [holding that “the failure of [the unwed father] to provide prebirth assistance to pregnant mother, when he was able and assistance was needed, vested [the] mother with the sole parental authority to consent to the adoption of the child and removed from the natural father the privilege of vetoing the adoption by refusing to give consent,” in light of “the public policy interests of society in encouraging unwed fathers to assume parental responsibilities”]; In re Baby Girl Eason, supra, 358 S.E.2d 459, 462-463 [although an unwed father has an “opportunity interest” in developing a parent-child relationship under the due process and equal protection clauses of the Fourteenth Amendment, that interest “begins at conception” and may be lost “if not timely and diligently pursued”]; Matter of Adoption of Baby Boy S. (1991) 16 Kan.App.2d 311 [822 P.2d 76, 78] [affirming decision to terminate unwed father’s parental rights and allow adoption because unwed father “made no effort to inquire after the welfare of the mother in her pregnant condition,” lived with her only briefly, and did not provide food or money after he learned of her pregnancy]; Matter of Kailee C.C., supra, 579 N.Y.S.2d 191, 192 [affirming judgment that unwed father was not entitled to veto adoption when, upon learning of the pregnancy, he quit his job and “essentially became a street person,” suggested abortion but acceded to adoption, left the adoption arrangements to the mother’s parents, and did not “manifest any interest in the child during the critical period prior to birth and placement,” but only “told several friends that he was responsible for the pregnancy and desired involvement in the child’s life”]; Matter of Adoption of Baby Boy W. (Okla. 1992) 831 P.2d 643, 646 [under Oklahoma law, a court may terminate an unwed father’s parental rights and allow adoption without a showing of unfitness if the father fails to prove that he has both contributed to the support of the mother during pregnancy and contributed to the support of the child after birth].)
IV.
Mark contends that John and Margaret’s reading of Kelsey S., supra, 1 Cal.4th 816, would unfairly discriminate between unwed mothers and unwed *1059fathers. In support of this contention, he notes that all an unwed mother must do to obtain a virtually absolute statutory right to withhold consent to an adoption is to show that she has a biological link with the child by proving that she gave birth to it (§§ 7610, subd. (a), 8604-8606), and that the mother possesses this statutory right after birth even if she has consistently and openly consented to adoption throughout her pregnancy. According to Mark, such disparate treatment would not only conflict with what he asserts is the premise of Kelsey S., i.e., that unwed mothers and unwed fathers are entitled to essentially the same rights in adoption proceedings, but would also violate the equal protection clauses of both the Fourteenth Amendment and article I, section 7, subdivision (a), of the California Constitution.
Mark cites no authority for this contention other than a statement in Kelsey S. that “The anomalies under [our] statutory scheme become readily apparent. A father who is indisputably ready, willing, and able to exercise the full measure of his parental responsibilities can have his rights terminated merely on a showing that his child’s best interest would be served by adoption. If the child’s mother, however, were equally of the opposite character— ««ready, ««willing, and ««able—her rights in the child could nevertheless be terminated only under the much more protective standards of [sections 8604 and 8606]. Such a distinction bears no substantial relationship to protecting the well-being of children. Indeed, it has little rationality.” (Kelsey S., supra, 1 Cal.4th 816, 847, italics in the original.)
Although Mark’s contention seems plausible at first blush, it has at least two fatal flaws. First, we held in Kelsey S. that despite its apparent anomalies our statutory scheme passes constitutional muster except “to the extent it is applied to an unwed father who has sufficiently and timely demonstrated a full commitment to his parental responsibilities.” (Kelsey S., supra, 1 Cal.4th 816, 849, italics in original.) As explained in part III, ante, the words “promptly” and “timely” in Kelsey S. mean within a short time after the father knew or reasonably should have known that the mother was pregnant with his child. In effect, therefore, we rejected the contention that Mark now raises when we decided Kelsey S. His quarrel is thus with Kelsey S. itself, rather than with John and Margaret’s reading of it; and to the extent he now invites us to reconsider Kelsey S,, we decline the invitation.
Second, the many public policy justifications that John and Margaret have provided and that we have discussed at some length in part III, ante, clearly demonstrate that any disparate treatment resulting from Kelsey S. is “ ‘substantially related’ ” to a significant number of “ ‘important governmental objectives,’ ” and therefore does not unconstitutionally discriminate between unwed fathers and unwed mothers on the basis of sex. (Caban v. Mohammed, *1060supra, 441 U.S. 380, 388 [60 L.Ed.2d 297, 304-305], quoting from Craig v. Boren (1976) 429 U.S. 190, 197 [50 L.Ed.2d 397, 406-407, 97 S.Ct. 451].)
V.
We conclude that an unwed father has no federal constitutional right to withhold consent to an at-birth, third party adoption under our decision in Kelsey S., supra, 1 Cal.4th 816, 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.
Here the trial court found that Mark learned that Stephanie was pregnant with his child in early July 1990, that between July 1990 and November 1990, “it cannot be said that he was fully committed to his parental responsibilities . . . [and] he clearly planned with Stephanie to give the child up.” (Italics added.) The court further found that although Mark decided in November 1990 that “he did not want his child given up for adoption,” he “continued to speak to Stephanie and even [John and Margaret] as though he still agreed with the adoption” until March 7, 1991, some two weeks after Michael was born. In light of these findings, we conclude that under Kelsey S. Mark has no constitutional right to withhold his consent to Michael’s adoption and that the Court of Appeal erred in ruling to the contrary.4
We therefore reverse the judgment of the Court of Appeal with directions to remand the cause to the superior court for entry of judgment against Mark on his claim he has a constitutional right to veto adoption, against Mark on his petition to declare the existence of a father-child relationship (§ 7630, subd. (c)), and in favor of John and Margaret on their petition to terminate Mark’s parental rights and adopt Michael (§ 7662).
Lucas, C. J., Arabian, J., Baxter, J., George, J., and Werdegar, J., concurred.
Effective January 1, 1994, the Legislature repealed the Civil Code sections governing adoption and reenacted them as part of the new Family Code. (Stats. 1992, ch. 162, §§ 4, 10.) There is no substantive difference between the relevant sections of the Family Code and their predecessors in the Civil Code.
All further statutory references are to the Family Code unless otherwise stated.
A determination that an unwed father has a constitutional right to veto adoption absent a showing of unfitness under Kelsey S. is not a final judgment in and of itself, nor is it an appealable interlocutory order. (Code Civ. Proc., § 904.1, subd. (a).) Here, however, John and Margaret waived the contention that Mark is unfit by noticing an appeal rather than raising that issue in the trial court. Because of this waiver, the order appealed from was in effect a “final determination of the rights of the parties” from which an appeal may be taken. (Lyon v. Goss (1942) 19 Cal.2d 659, 670 [123 P.2d 11]; accord, UAP-Columbus JV 326132 v. Nesbitt (1991) 234 Cal.App.3d 1028, 1034-1036 [285 Cal.Rptr. 856].)
Between November 1990 and March 7, 1991, Mark sought free legal advice, contacted the media, and requested assistance from local political figures. Because he was unable to find an attorney who would take his case free of charge, Mark researched the law himself and filed a custody petition in Arizona in February 1991. He found an attorney who would take his case on March 7, 1991, and the latter contacted John and Margaret to immediately request custody. He also sent out birth announcements and bought things for Michael as soon as he learned of his birth.
There is no need for yet further evidentiary proceedings on whether Mark is entitled to constitutional protection under Kelsey S. because the trial court’s existing findings are responsive to and dispositive of this issue. To remand the cause for such further proceedings, moreover, would be to delay resolution of an already lengthy lawsuit and protract the uncertainty it has brought into the lives of all concerned, particularly the minor child, beyond the four-plus years already elapsed.