Ever since Justice Anthony Kennedy’s June announcement that he would retire from the Supreme Court, the spotlight has been on Roe v. Wade, the 1973 decision legalizing abortion. Less than a day after the news broke, The Washington Post was reporting on the “real possibility” of abortion becoming illegal. Anti-abortion activists proclaimed that they were on the threshold of a historic moment: “In the history of the right-to-life movement, there has never been a more important time for us to come together and stand united,” Carol Tobias, the president of National Right to Life, wrote in a July newsletter. Kristan Hawkins, president of the group Students for Life, tweeted: “THIS IS NOT A DRILL.”

Whether Roe is overturned will in all likelihood depend on Donald Trump’s nominee to the Court, Brett Kavanaugh, a staunch social conservative. And if it is struck down in the coming years, what comes next? An emboldened anti-abortion campaign could lead to consequences for women’s health care and reproductive rights that range far beyond abortion restrictions. Contraceptive devices, such as IUDs or even the pill, could cease to be covered by insurance. But there is one procedure, in-vitro fertilization (IVF), that is curiously absent from this debate, though it results in the destruction of embryos.

Anti-abortion leaders are open about why they won’t go near it, revealing insights into the tactics and motivations of their movement. “It’s much more difficult to try to explain what is objectionable about IVF,” says Ann Scheidler, who founded the Pro-Life Action League with her husband in 1980. “You can only do what you can do with the resources you have, and we choose to really focus on the abortion issue.”

IVF poses a puzzling challenge for conservative groups: How do organizations that liken embryos to people reckon with a technology that creates babies for families, but destroys embryos along the way?

The first “test-tube” baby was born in 1978, meaning that not enough cyclical time has passed to comprehensively understand what will happen to most embryos that go unused during the IVF process. Some, for example, are frozen, ostensibly so they can be used at a later date. What’s clear, though, is that millions are rendered unviable. In other words: disposed.