Last month, Susan Buchweitz recovered a million dollars in a settlement with a fertility clinic. Doctors at the clinic had mistakenly given her an embryo intended for another family.

Now the boy is three, and Buchweitz's right to remain his mother is in question. The possibility that she may lose her son - by virtue of the DNA that he shares with a different family - reveals a kind of sex discrimination that often goes unnoticed.

The Doctors' Error

For many years, Buchweitz had dreamed of becoming a mother. Like other women, she had initially hoped to find a partner in her quest for parenthood. But when things did not work out, she decided to pursue the difficult and awesome responsibility of having a baby and raising him by herself. At the age of 47, Buchweitz went to a fertility clinic and had an embryo implanted in her womb. She carried her child for nine months and then delighted when her plan came to fruition, and she gave birth to a baby boy.

Ten months later, however, she found out that she might lose her son. It was not because she did anything wrong or had failed to lavish sufficient love and attention on him. It turned out that her doctor had made a mistake and implanted an embryo that was meant for someone else.

The doctor in question reportedly told Buchweitz that he knew of his error almost immediately after making it. He failed to tell her, however, because he was afraid that she would terminate her pregnancy. He decided to leave it "in God's hands."

The Ensuing Tort Litigation

As noted above, Buchweitz subsequently sued and received a million dollar settlement. The case was straightforward. The doctors should have taken greater care to ensure that they did not implant an embryo in a woman whose status as the child's parent would foreseeably be contested.

The fertility specialists' job was to help Susan Buchweitz and the other couple (whose identity has not been disclosed) conceive babies whom each, respectively, would be entitled to keep. The doctors failed spectacularly at that job.

Now, Buchweitz faces much more difficult litigation. She must defend a lawsuit in which the other couple seeks custody of her son. Thus far, a family court in California has awarded the biological father twice-weekly access to the child and has given Buchweitz temporary custody.

The Essence of Motherhood

The couple, according to Buchweitz, "don't accept me as my son's mother." In their view, the woman who takes care of him now has no claim to him at all. Buchweitz says that this is the worst part of the mix-up.

The competing parents, of course, were not to blame for the error. Indeed, they too may have a legitimate interest in a parental relationship with the little boy who has known only one mother. But compared to what Buchweitz invested in the existence of the boy, the superiority of the couple's claims is anything but obvious.

As I discussed in an earlier column, the attributes that define a "mother" are ordinarily all assembled in one person. Therefore, it is typically unnecessary either to rank them in order of importance or to determine which, if any, are superfluous and which are essential to the status in question. Salient among the attributes are pregnancy, a genetic link, and an expressed intention to raise and care for a child as one's own.

In this case, both Buchweitz and the couple did what would ordinarily have resulted in their respective acquisition of full parental rights. The couple went to a fertility specialist and asked for the retrieval and implantation of an embryo created from the husband's sperm and a donor egg. Buchweitz requested an embryo that had been donated precisely for someone who would implant it and give birth to a child who would be her own. She was not a volunteer surrogate mother, and the couple did not voluntarily donate an embryo to a stranger.

In the light of what each of the parties did, it is therefore puzzling that the couple would consider it so obvious that the "real" parent is the one with a genetic connection. The willingness to leap to this conclusion reflects a very male-centered orientation to the essence of what it is to be a mother.

Fatherhood Should Not Be the Paradigm by which Motherhood Is Judged

Think about how one becomes a father. Ordinarily, a man achieves biological paternity by providing sperm cells that unite with egg cells to divide and ultimately grow into a human being. Once a child is born, the man is a father simply by virtue of that initial contribution. Over time, he may prove to be a good or a bad father. To acquire the status in the first place, however, usually demands only a sperm contribution and a nine-month wait.

Consider, by contrast, the meaning of biological motherhood. Conception (and the DNA input entailed) only begins the process of maternity. Pregnancy makes significant demands of a woman. For women, "biological motherhood" is at least as likely to evoke an image of pregnancy as it is of egg donation. Unlike in the case of paternity, then, one can find oneself the biological child of two women, if one woman gestates and the other contributes an egg. I discussed this possibility in a prior column.

Still, even when it comes to women and maternity, many fixate on DNA when all other things are equal. And in this case, all other things are. There is not even a colorable argument, for example, that Buchweitz somehow waived her parental rights, or that she otherwise knowingly carried a child who could be claimed by other people.

Ignoring Gestation As A Claim to Biological Motherhood

To define away pregnancy as a nonessential ingredient of biological motherhood is thus to dismiss as irrelevant the unique (and clearly essential) contribution that women make to the perpetuation of our species. To focus exclusively upon Buchweitz's failure to contribute DNA is to suggest that the only important aspect of biological parenthood is the part in which men can participate -- the contribution of DNA.

Some might respond here that by focusing on DNA, we treat men and women equally. It is not, after all, a man's fault that he cannot gestate a child, so why should he be penalized?

This question, though, assumes that pregnancy is simply an advantage that women have over men, for which they should get no credit, much as men should not be given points for their (on average) superior height and physical strength. It ignores the reality that carrying a pregnancy is not simply a capacity that women alone have; it is also a difficult job that some women perform.

If a woman does not carry a pregnancy to term, the fact that she theoretically could (i.e., her gender-based capacity) does not alone entitle her to call herself a child's mother. But if she does make her special contribution, then it is a form of sex discrimination to pretend that she did nothing of value, simply because what she did is uniquely female.

To be sure, there are other ways of becoming parents beside the biological. Adoptive parents are rightfully offended when people ask about their children's "real" parents, referring to the biological mother and father. In Buchweitz's case, however, no one has offered to give up the little boy she has raised for three years. Two different families attempted to create a child who would be theirs, respectively, and each succeeded in that attempt. The dispute here is thus over who the true biological parent is.

To factor Buchweitz out of the equation would thus not only do her an injustice but would treat paternity as the paradigmatic way of becoming a parent. This represents a biased approach to reproduction.

Susan Buchweitz should not have to rely on financial compensation to make her whole. She should be given her rightful place in the class of people who are legitimately the parents of the baby to whom she gave birth.

Has Buchweitz Given Up Her Maternal Rights By Suing Her Doctors?

One issue remains, however. Buchweitz sued and recovered money from the insurer of her fertility providers. Doesn't this weaken her claims to the boy?

It might seem so, for two reasons. First, her suit against her providers might look like a statement from her that she is somehow dissatisfied with the child that resulted from her fertility treatment. Second, her financial recovery might appear to stand as a substitute for the relationship that she had hoped to have (but has now resigned herself to giving up) with her child.

On closer scrutiny, however, neither conclusion follows from the earlier litigation. First, Buchweitz evidently was and continues to be happy with the child to whom she gave birth. She considers him her son and herself his mother. Her suit and recovery reflect the fact that because of the fertility doctors' errors, she faces the possibility of losing her child, and she must fight for rights that should have been hers automatically. She is not dissatisfied with the child, in other words, but with her own precarious status. (For the same reason, the couple suing for custody should perhaps also be able to recover from the fertility specialists' insurers.)

Second, the cost - in money and emotional anguish - of having to fight for custody is real, precisely because Buchweitz does love her son and does not want to give him up to another family. It is for that cost that she could legitimately claim recovery against the fertility clinic.

But these costs and Buchweitz's recovery do not tell us who is and who should be the parents of one three-year-old boy. For that, we must rely on the Solomonic wisdom of the courts.