The first-ever randomized clinical study on the medically unproven “abortion reversal” treatment being pushed by anti-choice advocates has ended early as a result of safety concerns for participants, according to UC Davis Health, the academic health center where the research was being conducted.

The study sought to enroll 40 pregnant people who were planning to have a medication abortion and test the effectiveness of progesterone as a way to “reverse” an abortion. At the time of its conclusion, only 12 participants had enrolled. Of those, one participant who had received progesterone and two who had received a placebo experienced severe bleeding that required ambulance transport.

The discovered risk of “serious blood loss” when patients stop in the middle of the medication abortion protocol led principal investigator Professor Mitchell Creinin at UC Davis Health and his colleagues to end the study early. As a result, there remains no established scientific evidence that “abortion reversal” is possible. 

“Women who use mifepristone for a medical abortion should be advised that not following up with misoprostol could result in severe hemorrhage,” Dr. Creinin said in a statement for UC Davis Health.

Medication abortion relies on two drugs—mifepristone and misoprostol—to terminate a pregnancy. The pregnant person first takes a dose of mifepristone, which blocks progesterone receptors and stops the pregnancy from continuing to develop. Twenty-four to 48 hours later, they take a dose of misoprostol, which causes the uterus to contract and empty itself. 

In recent years, anti-abortion activists have alleged that injecting a pregnant person with progesterone after they’ve taken mifepristone, but before they’ve taken the misoprostol, will allow the pregnancy to continue and therefore “reverse” the abortion. 

This progesterone regiment is not FDA-approved, and it’s never been studied with rigorous scientific procedures such as those undertaken by Creinin’s team. The American College of Obstetricians and Gynecologists (ACOG) has fully denounced the practice. But that hasn’t stopped the anti-choice movement from launching a full-blown “abortion reversal” misinformation campaign and offering the “procedure” at crisis pregnancy centers across the country. 

Those pushing “abortion reversal” rely on an unscientific report involving seven anecdotes of people who had undergone the reversal regiment. The report was published by anti-abortion doctors Dr. George Delgado and Dr. Mary Davenport in 2012. Of the seven subjects, two had complete abortions and one ended their participation without a response. 

The anecdotes of four doctors who treated four people are the beginnings of this myth. In 2018, Delgado published more cases from his network of anti-abortion doctors who are apparently spending their time experimenting on pregnant people. The journal that published the report recalled the paper shortly after publication because an ethics board never fully approved Delgado’s research, which also had no control group. Both are very serious research failures. 

Here’s the problem with relying entirely on anecdotes and calling it scientific research: You can’t establish any semblance of a causal relationship. That matters in this case because science has already established that taking mifepristone and failing to take misoprostol results in anywhere from 8 percent to 46 percent of pregnancies continuing normally with no abortion occurring. The pregnancy outcomes recorded by Delgado could be entirely attributed to the lack of misoprostol and wholly unrelated to the progesterone injections; there’s no way to know because there was no control group. 

But four anecdotes and a recalled paper are apparently more than enough for conservative politicians across the country to codify what looks a whole lot like medical malpractice. In at least eight states, legislators have passed laws forcing abortion providers to trick their patients into believing that abortion reversal is a real medical procedure that’s available and effective. In 2019 alone, five states have passed these mandatory deception laws, and Ohio is moving another right now. Several of these laws have already failed legal tests, with a federal judge opining that North Dakota’s defense of its abortion reversal legislation was “Devoid of scientific support, misleading, and untrue.”

Medication abortion is becoming an increasingly common and accessible way to safely end a pregnancy, and abortion opponents and their allies in state legislatures are aggressively responding by pushing these restrictions. In 2017, nearly 40 percent of abortions in the United States were medication abortions. Spreading lies about abortion reversal is just the right’s latest strategy for denying bodily autonomy. 

The myth of abortion reversal is particularly attractive to the anti-abortion cause because it centers itself on the false premise that people who have abortions often regret them, a stigmatizing belief that simply isn’t grounded in fact. Different people feel different emotions after having an abortion, but regret is almost never one of them. In fact, 95 percent of people who’ve had an abortion reported feeling that abortion was the right choice for them. Abortion reversal practitioners are targeting pregnant people at a time when they are often emotionally vulnerable and using their bodies to further an ideological agenda with little concern for the potential effects.

These new findings from UC Davis Health are further evidence that abortion reversal can be dangerous—both as a fictitious narrative and as a medical practice.