Feminists often argue, correctly no doubt, that many pro-lifers are motivated less by concern for the unborn than by the belief that women who enjoy sex should pay a penalty for it. But maybe even more people today have a similarly punitive attitude toward men. In some comments I have heard, from both men and women, about the danger of "letting men off the hook," the real fear seemed to be not that the children would suffer, but that the men would get off scot-free.

The willingness to liberate women but not men from the unwanted consequences of sex may stem partly from the lingering attitude, conscious or not, that sex is mainly for the man's pleasure. It may also reflect the belief that men are irresponsible and thus more likely to abuse their freedom.

Some day, perhaps in our lifetime, science will add a new wrinkle to these issues. Reproductive technology will have advanced to the point where the fetus can be taken from the womb early in the pregnancy, with no more medical risk than an abortion, and incubated until it becomes viable. Will the law then allow the man to petition for custody of the unborn child if the woman doesn't want it? Will he be able to sue her for child support afterward? Will many feminists argue that it's an intolerable violation of a woman's reproductive freedom that her child should be brought into the world without her consent, let alone that she should be stuck with the bill?

In the meantime, we have to deal with biological realities as they are. Given these realities, it may be nearly impossible to come up with a solution that wouldn't be unfair either to men or to women. The current situation is clearly inequitable to men. But allow a veto for fathers, and it raises the disturbing specter of giving a man authority over a woman's body. Allow choice for men, and some will find it galling that a woman who wants to avoid the burden of parenthood has to undergo surgery or drug treatment with unpleasant side effects while a man merely fills out some forms.

The argument for at least notifying the prospective father of an abortion (with a waiver for cases in which the woman has a reasonable fear of bodily harm from the man, or the pregnancy results from rape), seems compelling. Shostak, co-author of "Men and Abortion," believes that a man should have an opportunity to "plead his case" to a woman if he wants her to have their baby.

There is also a strong case for providing some options for men to terminate their paternity. (At the very least, a woman who never bothered to let the man know that he was a daddy shouldn't be able to hit him up for back pay 10 or 15 years later.)

Of course, "choice for men" could have complications beyond the issue of children's economic welfare; for one, the man could later have a change of heart. While proposals for a "paper abortion" would make the procedure irrevocable, Fred Hayward concedes that "it's a tough one," since sometimes the child could clearly benefit from reestablishing a relationship with the father.

McCulley believes that a quick, early paternity termination would be better for the child than long, traumatic and often ultimately unsuccessful battles to extract money from an unwilling father. More intriguing, some proponents of men's right to choose, such as Jack Kammer, author of the online book "If Men Have All the Power How Come Women Make the Rules," argue that the option of declining fatherhood would make child abandonment less common.

"The notion of fatherhood as a trap, a burden, a yoke is strong in male culture," says Kammer. "By making fatherhood a choice, we will allow it to become an obligation freely taken, not to be resented or avoided."

And that, advocates for men say, is the real point -- not men's ability to control women or to desert children, but the ability to have input in decisions that profoundly affect their lives.

Maybe there is no good answer to the dilemma of male reproductive rights. Still, it is an issue that should prompt us to rethink some deeply held assumptions. It should make us realize that, if men who want a right to be released from their parental obligations seem callously egocentric to many people, that's how women who want abortion on demand look to many anti-abortion advocates. It should make us ponder the fact that, while paternal desertion is often cited as evidence of male irresponsibility and selfishness, more than a million American women every year walk away from the burdens of motherhood.

Above all, perhaps, the issue of men's reproductive autonomy brings home the fact that abortion can create a radical imbalance rather than equality between the sexes. For years, women have been sending a mixed message to men: Sometimes we expect them to be full partners in child-rearing, sometimes we treat them as little more than sperm donors, walking cash machines or bystanders. If men's parental role is to be taken seriously, women need to assume a moral, if not legal, obligation to involve their partners in any decision about pregnancy and we all need to have a serious conversation about men's reproductive rights -- no matter where that conversation may lead.

Order "Mothers Who Think: Tales of Real-Life Parenthood" from the editors of Mothers Who Think.