K.M.

*134 Opinion

We granted review in this case, as well as in Elisa B. v. Superior Court (2005) 37 Cal.4th 108 [ 33 Cal.Rptr.3d 46 , 117 P.3d 660 ], and Kristine H. v. Lisa R. (2005) 37 Cal.4th 156 [ 33 Cal.Rptr.3d 81 , 117 P.3d 690 ], to consider the parental rights and obligations, if any, of a woman with regard to a child bom to her partner in a lesbian relationship.

In the present case, we must decide whether a woman who provided ova to her lesbian partner so that the partner could bear children by means of in vitro fertilization is a parent of those children. For the reasons that follow, we conclude that Family Code section 7613, subdivision (b), which provides that a man is not a father if he provides semen to a physician to inseminate a woman who is not his wife, does not apply when a woman provides her ova to impregnate her partner in a lesbian relationship in order to produce children who will be raised in their joint home. Accordingly, when partners in a lesbian relationship decide to produce children in this manner, both the woman who provides her ova and her partner who bears the children are the children’s parents.

Facts

On March 6, 2001, petitioner KM. 1 filed a…

Unlike the majority, I would apply the controlling statutes as written. The statutory scheme for determining parentage contains two provisions that resolve K.M.’s claim to be a parent of the twins bom to E.G. Under one provision, a man who donates sperm for physician-assisted artificial insemination of a woman to whom he is not married is not the father of the resulting child. (Earn. Code, § 7613, subd. (b).) 1 Under the other provision, mies for determining fatherhood are to be used for determining motherhood “[ijnsofar as practicable.” (§ 7650.) Because K.M. donated her ova for physician-assisted artificial insemination and implantation in another woman, and knowingly and voluntarily signed a document declaring her intention not to become a parent of any resulting children, she is not a parent of the twins.

I.

In 1994, K.M. and E.G. began living together as a couple, and some months later they registered as domestic partners. E.G. had long wanted to become a mother but had been unsuccessful in conceiving. She eventually pursued in vitro fertilization, but her body failed to produce sufficient ova. Her physician then suggested that she obtain ova from K.M., her partner. K.M.…

The majority determines that the twins who developed from the ova K.M. donated to E.G. have two mothers rather than one. While I disagree, as I shall explain, with that ultimate conclusion, I agree with the majority’s premise that a child can have two mothers. Our previous holding that “for any child California law recognizes only one natural mother” (Johnson v. Calvert (1993) 5 Cal.4th 84, 92 [ 19 Cal.Rptr.2d 494 , 851 P.2d 776 ] (Johnson)) must be understood in the context in which it arose—a married couple who intended to become parents and provided their fertilized ova to a gestational surrogate who did not intend to become a parent—and, thus understood, may properly be limited to cases in which to recognize a second mother would inject an unwanted third parent into an *149 existing family. When, in contrast to Johnson , no natural 1 or adoptive father exists, two women who intend to become mothers of the same child may do so either through adoption (Sharon S. v. Superior Court (2003) 31 Cal.4th 417 [ 2 Cal.Rptr.3d 699 , 73 P.3d 554 ]) or because both qualify as natural mothers under the Uniform Parentage Act (Earn. Code, § 7600 et seq.) (UPA), one having donated the ovum and…