Trial investigating "abortion pill reversal" stops due to safety concerns

By Sally Robertson, B.Sc.Dec 9 2019

Scientists are calling for pro-life states in the US to stop offering women an unproven medication that some have claimed can "reverse" a medical abortion.

Image Credit: Ivanko80 / Shutterstock.com

Laws should not mandate counseling or provision of any treatment that claims to reverse abortion when both its efficacy and safety are unclear."

Mitchell Creinin, Obstetrician-gynecologist, University of California, Davis

The call follows the outcomes of a study led by Creinin looking into the safety and effectiveness of the controversial practice, known as "abortion pill reversal."

The trial was halted because three women bled so heavily, they had to be rushed to the emergency room for treatment.

Six states require doctors to offer the controversial approach to patients

A medical abortion uses a combination of two medicines that are usually taken 24 hours apart. The first is mifepristone, which is a progesterone blocker, and the second is misoprostol, which makes the uterus contract. Studies suggest that almost all women who take both medications as instructed will end their pregnancy safely.

Currently, six pro-life states have implemented laws that require doctors to inform patients that there is a medication that can "reverse" a medical abortion. Proponents of the reversal treatment offer progesterone to women who have taken mifepristone but then changed their minds about completing the abortion. One group of researchers, who published a small case series, claimed the intervention does stop the abortion from going ahead.

That research has been heavily criticized for being flawed, and most obstetricians-gynecologists oppose the protocol, saying there is no science to support that administering progesterone after mifepristone is effective, let alone safe.

For now, the level of evidence is still inadequate to support or refute the benefits and risks of progesterone treatment to stop a medical abortion after taking mifepristone."

Mitchell Creinin, Obstetrician-gynecologist, University of California, Davis

What did the study involve?

For the study, Creinin and colleagues set out to recruit 40 women who had decided to have a surgical abortion, but who did not mind waiting a couple of weeks before undergoing the procedure.

The women were given the first abortion reversal medication – mifepristone - but not the second one - misoprostol. Instead, they were randomly assigned to receive either progesterone or a placebo.

Follow-up visits were planned for two weeks after the mifepristone had been taken to see whether the women were still pregnant.

The whole trial was shut down

As reported in the journal Obstetrics and Gynecology, the trial took a turn for the worst and was stopped when only 12 women had enrolled.

Of those 12 women, three suffered vaginal bleeding that was so severe they had to be rushed to a hospital for emergency treatment. One of the women had received progesterone, and the other two had received a placebo.

The risk to participants was too great to continue, and the whole trial was shut down.

The results raise concerns about the safety of taking mifepristone without then taking the second abortion reversal pill.

"Women who use mifepristone for a medical abortion should be advised that not following up with misoprostol could result in severe hemorrhage, even with progesterone treatment," says Creinin.

In several states, including Kentucky, Nebraska, and Oklahoma, advocates for medical abortion reversal have succeeded in enacting laws to ensure the regimen is discussed as an option during mandatory pre-abortion counseling.

Opponents have objected, saying that there is insufficient evidence to support the approach. Now, there is evidence to suggest it causes harm.

"Encouraging women to not complete the regimen should be considered experimental," says Creinin. "We have some evidence that it could cause very significant bleeding."

"It's not that medical abortion is dangerous," he says. "It's not completing the regimen, and encouraging women, leading them to believe that not finishing the regimen is safe. That's really dangerous."

Since the trial was stopped early, it could not answer the question it set out to, says Creinin, who adds that there are simply not enough data to know whether progesterone treatment is effective at preventing a medication-based abortion from taking place.

"Does progesterone work? We don't know," he says. "We have no evidence that it works."