Abortion opponents won major victories last week when Louisiana lawmakers voted to ban abortions as early as six weeks into a woman’s pregnancy and the Supreme Court upheld an Indiana law requiring the burial of fetal remains in Box v. Planned Parenthood of Indiana and Kentucky Inc.

So what happens if Roe v. Wade falls?

Abortion won’t disappear. Our research shows that countries where abortion is illegal have higher rates of abortion than in the United States — figures which are largely a function of unwanted pregnancies. Nearly half of all pregnancies here are unintended, of which four in 10 end in abortion.

But it takes two to make an unwanted pregnancy. That’s why we need to talk about men when we talk about abortion.

The last time we included men in the discussion was 1992, when the Supreme Court wisely overturned Pennsylvania’s law requiring a woman seeking an abortion to prove she had first notified her husband. That’s right — attempting to give men veto power over women was the only meaningful effort to include men in abortion regulation.

Our entire abortion debate pits the fetus against the woman. Men are absent. They can shrug off an unwanted pregnancy as someone else’s problem, even though they contributed half the genetic material to the fetus. Most men probably won’t think the abortion bans littering statehouses have anything to do with them.

They are both wrong and right.

It would be easy to apply these laws to men, to punish them in the ways we have long punished women. But we also know that’s not going to happen.

Alabama’s abortion ban, for example, exempts women from criminal punishment. But if the Supreme Court allows the law to stand, and all abortions become illegal, a man could easily be prosecuted.

Here’s how. Say John and Jane have gotten pregnant, and they want to end the pregnancy. This is a common scenario, as ethics professor Katie Watson has found. Nearly nine in 10 unwanted pregnancies happen in relationships, and most abortion patients say their male partners support their decision.

If John buys abortion drugs online, or even encourages Jane to, then he could serve from 10 to 99 years in prison for aiding her. This happened in 2014 to a Pennsylvania mother, imprisoned for buying her teenage daughter abortion drugs.

Things get worse for John when you consider that Alabama, along with other states that have passed embryonic heartbeat laws, grants personhood to fetuses as early as two weeks after a missed period.

If a fetus is a child, then John is a parent.

John can’t abandon his child and is legally obligated to protect it. Current law gives Jane the exclusive right to decide whether to end her pregnancy. But if abortion is a crime, John’s obligations to the fetus may shift. If John walks away, knowing he got her pregnant and suspecting she will have an abortion, he may be committing child neglect. Or worse — mothers have been found guilty of murder for having failed to prevent their partners from fatally abusing their children. It’s not clear what John is supposed to do. Nor is it clear whether John can avoid liability.

John may even have broken Alabama law before Jane got pregnant, by failing to take precautions to avoid unwanted pregnancy. Like most states, Alabama law criminalizes recklessly engaging in “conduct which creates a substantial risk of serious physical injury to another person.” When John ejaculated inside Jane without knowing whether she wanted a baby, he arguably showed a conscious disregard for the risks caused by pregnancy, whether from childbearing or abortion.

We know these prosecutions sound absurd. Indeed, we think they are a terrible idea. Prosecution won’t deter men from having unprotected sex. And the threat of any abortion-related prosecution already jeopardizes pregnant women’s lives, which is why the American Medical Association, the American College of Obstetrics and Gynecology and many states oppose prosecuting those who end their own pregnancies. Prosecuting men would intensify those risks: if John is angry or panicked about his own legal jeopardy, he might threaten or hurt Jane to force her not to abort.

And surely the last thing we need is another way to fill the nation’s prisons with men — especially since, as so often happens, punitive laws are disproportionately enforced against low-income people and people of color.

Maybe Alabama prosecutors will head to the white fraternities in Tuscaloosa and begin to arrest young men for conspiring to recklessly endanger the lives of the partygoers they hope to have unprotected sex with. But we doubt it.

Think about it, though. The novelty of prosecuting men for abortion — despite the sound legal footing of such charges — tells us something important about the way we have, until now, framed the debate. Boys will be boys, but women who get pregnant have behaved irresponsibly.

All men, whether leaders, legislators or just regular guys, should know that abortion is personal for them, too. They shouldn’t just speak to and about women. They must take responsibility for themselves.

Michelle Oberman is the author of “Her Body, Our Laws: On the Front Lines of the Abortion War, From El Salvador to Oklahoma” and a law professor at Santa Clara University, where W. David Ball is also a law professor.

The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. And here’s our email: letters@nytimes.com.

Follow The New York Times Opinion section on Facebook, Twitter (@NYTopinion) and Instagram.