This suit was brought by Catholic Charities of the Diocese of Galveston-Houston to terminate the parent-child relationship of an infant illegitimate girl (T.E.T.). The biological father filed a cross-action seeking to legitimate the child and be awarded custody. The trial court rendered judgment on *794the jury verdict1 that (1) the parent-child relationship between the mother and T.E.T. be terminated; (2) the father’s petition to legitimate T.E.T. be denied and all of his rights to the child be foreclosed; and (3) Catholic Charities be appointed managing conservator of T.E.T. The biological father appealed and the court of civil appeals affirmed. 583 S.W.2d 484.
The primary question presented is whether portions of the Texas Family Code deny equal protection as guaranteed by the United States Constitution2 to the biological father who has not established a substantial family relationship with the illegitimate child. We hold that the Family Code does not violate this constitutional guarantee and affirm the judgments of the courts below.
The child, T.E.T., was born in 1977. T.E. T.’s mother was fourteen and a freshman in high school and T.E.T.’s father was eighteen and a senior in the same school when the child was conceived. They were not married and, in fact, the girl was forbidden by her parents to have dates alone with a boy before she reached sixteen years of age. After much consideration and discussion of her alternatives with her parents and the father, the pregnant girl went to a home for unwed mothers operated by Catholic Charities. After additional counseling with respect to keeping the child or permitting its adoption, the mother concluded that it was in the best interest of the child to relinquish her parental rights and allow the child to be adopted. After T.E.T. was born, the mother executed an Affidavit of Relinquishment of Parental Rights, pursuant to Section 15.03.3
Under the Family Code the parent-child relationship is a legal status which carries with it certain rights, privileges, duties and powers. This status does not necessarily exist between mother or father and child, but rather exists between a “parent” and child. A “parent” is defined in Section 11.01(3):
“(3) ‘Parent’ means the mother, a man as to whom the child is legitimate, or an adoptive mother or father, but does not include a parent as to whom the parent-child relationship has been terminated.”
Section 12.02 describes when a child is the legitimate child of his father as follows:
“(a) A child is the legitimate child of his father if the child is born or conceived before or during the marriage of his father and mother.
“(b) A child is the legitimate child of his father if at any time his mother and father have attempted to marry in apparent compliance with the laws of this state or another state or nation, although the attempted marriage is or might be declared void, and the child is born or conceived before or during the attempted marriage.
“(c) A child is the legitimate child of a man if the man’s paternity is established under the provisions of Chapter 13 of this code.”
Chapter 13 of the Family Code authorizes the biological father of an illegitimate child to establish his status as a parent as follows:
Ҥ 13.21 Voluntary Legitimation
“(b) The court shall enter a decree designating the child as the legitimate child of its father and the father as a parent of the child if the court finds that:
“(3) the mother or the managing conservator, if any, has consented to the decree.
*795“(c) The requirement of consent of the mother is satisfied if she is the petitioner. If the entry of the decree is in the best interest of the child, the court may consent to the legitimation of the child in lieu of the consent of the mother or managing conservator."
This Court recently upheld the constitutionality of the statutory procedure in question. See In the Interest of K, 535 S.W.2d 168 (Tex.), cert. denied, 429 U.S. 907, 97 S.Ct. 273, 50 L.Ed.2d 189, reh. denied, 429 U.S. 1010, 97 S.Ct. 542, 50 L.Ed.2d 620 (1976). We said:
“There is a rational basis for the state, which has an interest in securing stable homes and supportive families for children, to distinguish between the father who has accepted the legal and moral commitment to the family and the father who has not done so. The biological father may be a sperm donor or a rapist or someone as S.D.A. who has simply engaged in a single hit and run sexual adventure. He may, on the other hand, be devoted to child and family even though the legal contract has not been sealed. Texas law offers the biological father of an illegitimate child the opportunity to prove which category in which he falls and to show that he should not be treated differently from fathers legally committed to the mothers of their children. Thus S.D.A. sought and received a fair hearing. The evidence proved him to be an unfit person to act as parent of this child, and the denial of his petition for parental status was shown to be in the best interest of the child. His rights have been respected. The rights of society and baby girl K permit him nothing more.”
Petitioner urges that our holding should be reexamined in view of the writing of the United States Supreme Court in Craig v. Boren, 429 U.S. 190, 97 S.Ct. 451, 50 L.Ed.2d 397 (1976), and in Caban v. Mohammed, 441 U.S. 380, 99 S.Ct. 1760, 60 L.Ed.2d 297 (1979). These cases are distinguishable and do not mandate a holding that the Texas Family Code denies the biological father of an illegitimate child the equal protection guaranteed by the Fourteenth Amendment to the United States Constitution.
In Craig v. Boren, supra, the United States Supreme Court held that an Oklahoma statute which prohibited the sale of 3.2% beer to males under the age of twenty-one and to females under eighteen constituted a denial to males eighteen to twenty years of age of the equal protection of the laws in violation of the Fourteenth Amendment. The Supreme Court did not strike down all gender-based classifications, but simply required that such a classification serve important governmental objectives and be substantially related to achievement of these objectives.
In Caban v. Mohammed, supra, the United States Supreme Court by a 5 — 4 vote struck down as unconstitutional the gender-based distinction in the New York adoption consent statute between an unwed mother of the child and the unwed biological father. Under the New York law, an unwed mother could veto an adoption, but an unwed father could not, even if the adoption by the biological father was in the child’s best interest. The Court made it clear that its Caban opinion must be read in the light of the unusual circumstances of the case.
There the unmarried parents had lived together for five years as husband and wife, during which period two children were born to them.4 They then separated and the mother married Mohammed. Eventually Mohammed sought to adopt the children with the mother’s consent. The facts of the Caban case illustrated the injustice of that discrimination as applied to parents who had lived as a family unit for years.
The limited extent of the Caban holding is emphasized by the issue as drawn by the dissent of Justice Stevens:
*796“With this much the Court does not disagree; it confines its holding to cases such as the one at hand involving the adoption of an older child against the wishes of a natural father who previously has participated in the rearing of the child and who admits paternity ... . ”
The majority itself states:
“Even if the special difficulties attendant upon locating and identifying unwed fathers at birth would justify a legislative distinction between mothers and fathers of newborns, these difficulties need not persist past infancy. When the adoption of an older child is sought, the State’s interest in proceeding with adoption cases can be protected by means that do not draw such an inflexible gender-based distinction as that made in § 111. In those cases where the father never has come forward to participate in the rearing of his child, nothing in the Equal Protection Clause precludes the State from withholding from him the privilege of vetoing the adoption of that child. . . . ”
The Caban Court carefully pointed out that appropriately limited distinctions between the rights of the mother and the rights of the father are not necessarily improper. In fact, by a footnote, the Caban opinion added this qualification: “We note some alternatives to the gender-based distinction of § 111 only to emphasize that the state interests asserted in support of the statutory classification could be protected through numerous other mechanisms more closely attuned to those interests.” (Emphasis added.)
The Texas voluntary legitimation statutes differ from the New York statute in that our Family Code does give the biological father reasonable opportunity to establish his status as a “parent.” Once this is done, he has equal rights with the mother who is identified as the child’s parent at birth. Section 13.21 provides in part that the court shall render a decree designating an illegitimate child as the legitimate child of its father and the father as a “parent” if the mother or managing conservator has consented to the decree, or in the absence of such consent, if the court finds that such decree is in the best interest of the child. Section 13.09 provides that the effect of a decree designating the alleged father as the “parent” of the child is to create the parent-child relationship with the child as if the child were born to the father and mother during marriage. The father then has the same rights, privileges, duties and powers as the mother. Thus it is seen that, contrary to the New York statute, a mother cannot veto the father’s acquisition of full parental rights.
A similar distinction was noted by the California court recently in rejecting the contention of a biological father that under the Caban holding the California adoption statute denied him the equal protection guaranteed by the Fourteenth Amendment. The Court pointed out that California (like Texas) grants the biological father an opportunity to establish by the best interest rule his status as a parent. W. E. J. v. Superior Court of Los Angeles, 100 Cal.App.3d 303, 160 Cal.Rptr. 862 (1979) (Hearing denied by the California Supreme Court, 1980).
The Texas Family Code recognizes that the individual child’s interest is paramount in each contested voluntary legitimation case. The validity of the “best interest rule” was specifically approved by the United States Supreme Court in Quilloin v. Walcott, 434 U.S. 246, 98 S.Ct. 549, 54 L.Ed.2d 511 (1978). In Quilloin, the Supreme Court unanimously upheld a Georgia statute which permits the biological father to legitimate his child only upon a showing of best interest of the child. It should be noted that the Georgia Code is very similar to the Texas Family Code regarding the rights of the father of an illegitimate child. Although the Supreme Court did not there consider a gender-based distinction, Quilloin rejected the contention that the equal protection clause requires that all biological fathers be treated equally. The Supreme Court expressly held that the Georgia statute conferring upon the fathers of legitimate children the right to veto adoption of the children while denying that right to the *797fathers of illegitimate children did not violate the equal protection clause.
The narrow issue before us is whether the gender-based distinction of the Texas statutory scheme for establishing status as a parent is substantially related to the important state objective of promoting the best interest of children born out of wedlock and is substantially related to the achievement of this objective. We hold that it is so related. We believe that in the light of the “special difficulties” a mother faces at the birth and during the infancy of an illegitimate child this slight legislative distinction is justified. See Caban v. Mohammed, supra.
We pointed out in K that there is a rational basis for the State to distinguish between the father who has accepted the legal and moral commitment to the family and the father who has not done so. The Caban holding, as heretofore pointed out, is supported by the fact that the father there had established a family relationship with the children. The State has a valid objective in requiring the biological father to establish his “status” as a parent. Otherwise, we would recognize a sperm donor, a rapist, a “hit and run” lover, an adulterer and the like in the same legal status as a father who had accepted the legal and moral commitment to his family. While recognizing this valid distinction, Texas law offers the biological father of an illegitimate child the opportunity to prove in which category he belongs.
Furthermore, the State has a legitimate interest in protecting the children who are born as a result of pre-marital sexual activity. The mother, by virtue of her pregnancy, is automatically responsible for the child. She has the physical burdens and responsibilities of the pregnancy. She can choose to abort the child or she may carry it full term. The State has a substantial interest in encouraging the unwed mother to properly care for the child by assuring her that her wishes as to the disposition of the child will not, absent her consent or a finding of the child’s best interest, be subject to the absolute veto of the biological father. This statute is substantially related to the achievement of that interest.
On the other hand, the biological father is not automatically responsible for the child. He may not have an interest in legitimating the child. He may not promptly disclose his interest in the child. In most situations, he can wait until after the child is born before committing himself. While the mother who is unmarried and pregnant is trying to figure out what she will do with the child, the father is totally free from any responsibility with respect to the child. To classify him as a parent simply because he is the biological father would give him a powerful club with which he could substantially reduce the options available to the unmarried mother. All must agree that an unmarried fourteen-year-old high school freshman has a serious problem when she discovers she is pregnant and she needs all the options that the State can properly make available to her.
It is easy to understand her decision here that it would not be in the child’s best interest for her to be turned over to the nineteen-year-old father and be reared by him in the small town where the illicit sexual activity occurred. On the other hand, the best interests of the illegitimate child will more likely be served by her adoption into a family who will give her the stability of a normal, two-parent home. Moreover, adoption will remove the stigma under which an illegitimate child suffers.
The biological father was given timely notice of the proceedings to terminate the mother’s parental rights and, in response, brought suit as permitted under the Texas Family Code to legitimate the child. He thus had the procedural due process required by Stanley v. Illinois, 405 U.S. 645, 92 S.Ct. 1208, 31 L.Ed.2d 551 (1972). A full and complete trial was had on the question of whether it was in the child’s best interest that the child be legitimated. The jury found that it was not in the child’s best interest and no complaint is made as to the sufficiency of the evidence to support such finding. Our facts differ sharply from those in Caban as the biological father here *798had never had a family relationship with the child. In fact, he had never lived with, raised, or established any kind of relationship with the child, having seen her only the one time shortly after her birth.
We hold that Section 13.21(b)(3) and (c) of the Family Code do not deny to the biological father, who has not established a substantial family relationship with the child, the equal protection guaranteed by the Fourteenth Amendment to the United States Constitution.
Petitioner urges by several points of error that the court of civil appeals erred in not reversing the judgment of the trial court and remanding the cause for a new trial because of certain procedural errors in the trial of the case. These complaints are primarily based on his contention that the mother and Catholic Charities were not antagonistic parties and the trial court should not have given each party six jury strikes and additional time for jury argument. The problem with this contention is that the cause began as a suit by Catholic Charities to terminate the parent-child relationship of the mother. This issue remained in the case and was submitted to the jury. Nevertheless, these parties were united by their pleadings and in spirit against the petitioner’s petition for paternity and custody. The mother and Catholic Charities have been represented by unrelated attorneys throughout the cause and there is no indication in the record of any collaboration either in the selection of the jury or in the presentation of the argument to the jury.
We agree with the court of civil appeals that the question of the number of jury strikes was not properly preserved by petitioner. Although inquiry was made by petitioner of the trial court as to how many strikes each party would be entitled to make, there was no objection by him upon explanation by the trial court that each of the parties would be entitled to six strikes. Thus, petitioner waived any complaint to this alleged error.
We also agree with the court of civil appeals that reversible error has not been shown by the other procedural errors asserted by petitioner.
The judgment is affirmed.
STEAKLEY, J., dissenting in which POPE and SPEARS, JJ., join..The jury found substantially as follows:
No. 1. “We do” find that it would be in the best interest of the child to terminate the parental rights of the mother.
No. 2. We find that it is in the best interest of the child that the father “should not be designated her parent.” (Emphasis added.)
. Petitioner does not address the question of the application of the Texas Equal Rights Amendment. See Article 1, Section 3a, of the Texas Constitution.
. Unless otherwise noted, references to sections are to sections of the Texas Family Code.
. Under Texas law, the children could have been declared legitimate children since they were born of the purported common law marriage. See Section 12.02(b).