Writing jointly for the Court on this aspect of the [Casey] decision, Justices O’Conner, Kennedy and Souter struck down the spousal notification requirement as in impermissible infringement on a woman’s right to privacy. The Court offered three basic reasons for holding that a wife could not be compelled to inform her husband of her intent to abort.

1. First, the Court discounted the husband’s interests by pointing to the realities of nature:

"[i]t is an inescapable biological fact that state regulation with respect to the child a woman is carrying will have a far greater impact on the mother’s liberty than on the father’s

In other words, because the fetus is in the woman and not the man, the woman’s interests trump.

This reasoning might be questioned on several fronts. First, it is not the case that the biology is all with the women. As dozens of studies of couvade syndrome indicate, expectant fathers experience biological symptoms of pregnancy along with their partners. Both partners may feel nausea, irritability, food cravings, indigestion, and so on. Both can anticipate discomforts from pregnancy and the stresses of infant care. While the man’s aches and pains are "psychosomatic," and are likely to be less intense than the woman’s, they are not inconsequential. Men and women both experience biological effects of pregnancy.

In any event, the right to privacy recognized in Roe v. Wade is not based on biology only, but also on issues of emotion and identity. Justices O’Conner, Kennedy and Souter stated as much in Casey, observing that the Fourteenth Amendment protects the most intimate and personal choices a person may make in a lifetime, choices central to personal dignity and autonomy. These choices include the right to define one's own concept of existence, of meaning, of the universe, and of the mystery of human life. This is not the language of biology, but of religion or philosophy.

The greater maternal involvement in biological pregnancy cannot by itself resolve these larger issues. What matters, in addition to the physical effects on the body, are the consequences of abortion for the individual’s basic value structure and self-concept. Once the liberty interest protected by the Fourteenth Amendment is phrased in terms of choices and a concept of the self, rather than biology alone, the argument that the woman’s interests should trump the man’s requires further elaboration. Both men and women face choices about their roles as parents and their concepts of their own identities. Both men and women become bonded with the fetus. The fetus may be physically growing in the woman’s belly, but in the geography of the psyche, it is inside the man as well. To exclude expectant fathers from juridical notice on grounds of biology is to miss the importance of pregnancy in a man’s concept of himself as a parent and a procreative being and his vision of the meaning of his life.