Mary Beth Whitehead was in court again the other week, trying to gain custody of the child she bore for William Stern. It is clear this issue is not going away.

According to Judge Irving Sorkow's original ruling, labor and pregnancy do not a mother make -- at least not in New Jersey. And marriage and intercourse do not establish paternity, either. According to the judge, Stern, who contracted with Whitehead for her womb's services, is the "natural" father of the baby girl who resulted from that pregnancy and the contract they signed is valid. Besides, the Sterns will be better parents.

Judge Sorkow's decision in the so-called Baby M case raises fundamental questions of family integrity, ethics of surrogacy, and biological vs. legal paternity. Who are Baby M's natural parents? Who should be her legal parents?

Judge Sorkow's opinion leaves no doubt as to his values. Baby M will clearly have more advantages and opportunities as the child of William and Elizabeth Stern. Thus, Judge Sorkow sets up a new standard for parenthood: annual income.

In contrast, consider the following three rules.

Rule 1: The woman who bears a child is its mother, until she relinquishes her rights and duties through adoption.

Modern adoption laws protect the child, the birth parents and the adoptive parents by assuring that consent is freely and voluntarily given. One underlying motive for these laws is to protect poor and/or gullible persons from exploitation. In addition, modern adoption laws assure that no one acts for profit. Likewise, federal organ donation laws attempt to protect the poor and/or gullible from exploitation by prohibiting the interstate sale of human organs.

Judge Sorkow ruled that "the surrogate parenting agreement is a valid and enforceable contract . . . constitutionally protected under the 14th Amendment." But contracts are not sacred cows. Some promises are unenforceable because they violate public policy or affront morality and decency. For example, a promise not to sue for divorce after adultery of one's spouse is unenforceable.

In this case, Whitehead's promise to surrender her child should be unenforceable because it comes too close to baby selling. Moreover, the contract deprives Whitehead of the right to withdraw consent to the surrender of her baby after her baby's birth.

Rule 2: A child born or conceived during marriage is presumed to be the legitimate issue of both spouses.

This rule is a modern version of Lord Mansfield's Rule, first stated in 1777 in an ejectment action between heirs: "It is a rule founded in decency, morality and policy, that {the parents} shall not be permitted to say after marriage that they have had no connection {read: intercourse}, and therefore that the offspring is spurious."

The presumption of legitimacy can be rebutted only by testimony of a person other than the husband or wife that they were living separate and apart at the time of conception. Once the presumption is rebutted, both husband and wife can testify that there was "nonaccess" {read: no intercourse} at the time the child was conceived.

Lord Mansfield's Rule has been abandoned by some states and limited or modified by others, in favor of scientific paternity testing. In our opinion, Lord Mansfield's Rule should be revitalized. In contrast to scientific paternity testing, it promotes orderly family relationships by resolving paternity questions in favor of the birth mother's legal husband whenever possible. As a consequence, the child is legitimate from the moment of birth. Pregnancy and matrimony determine who its parents are, not a laboratory test.

Rule 3: Any sperm or egg separated from the person whose body manufactured it, except in an act of sexual intercourse, should be treated legally as a "gift."

A child conceived from sexual intercourse, whether in or out of wedlock, whether conjugal or adulterous, has as its "natural" or birth parents (as distinct from its legal parents) those two people whose intercourse resulted in the conception. Adoption aside, paternity and maternity should be based upon sexual intimacy, not clinical insemination or technological manipulation.

On the other hand, if a child is conceived "artificially," without sexual intimacy or human connection, then no parental right or duty should be assigned to the person who "donated" the egg or sperm. An egg or sperm that is "donated" for purposes of artificial insemination should be considered like any other gift. The donor parts with all dominion and control over it, and the recipient of the gift acquires all the rights and responsibilities. An egg or sperm donor could not be sued, therefore, for paternity or maternity, or for producing a "defective" child, because the donor would not be a "parent" in the legal sense. ::

These three rules do not encourage or prohibit surrogate motherhood. By making the transaction subject to adoption laws, they protect the surrogate mother from exploitation and they prevent her from seeking profit. Even more basic, these rules establish that the rights and duties of maternity and paternity do not arise simply in the manufacture of egg and sperm.

Who is Baby M's "natural" mother? And who is her "natural" father? Whitehead is Baby M's natural mother. No one is her "natural" father. William Stern should have relinquished all rights to his sperm when it left his body. If the Whiteheads wish to allow the Sterns to adopt their baby, that is their legal right. In that case, the Sterns would become Baby M's legal, adoptive parents.

The rules we have described require no value judgments about which couple will best provide for Baby M financially or whose life style would be best for the child. Intercourse, pregnancy and marriage decide the case. Mary Beth Whitehead is the natural mother. Richard Whitehead is the legal father. Baby Sara Whitehead belongs with her parents.Neal J. Meiselman practices family law in Rockville. Terry M. Shuch of the Maryland bar is a graduate of Georgetown University Law Center. Jonathan P. Siegel, PhD, president of Information Communications Associates, Kensington, assisted in the preparation of this article. Second Opinion is a forum for points of view on health policy issues.