USA – Research on claims of “abortion pill reversal” stopped early

by Marge Berer

Amongst the seemingly endless anti-abortion efforts to destroy the provision of safe, legal abortion in the USA, has been an unproven claim that it is possible to reverse the abortifacient effects of mifepristone by taking progesterone. As the editor of this newsletter, I decided against reporting this up to now because the only “evidence” put forward (by a handful of anti-abortion doctors in the USA) was and has remained too thin to draw any conclusions from it, based literally on a handful of cases and without a control group. Unfortunately, the European Journal of Contraception and Reproductive Health Care published the study in December 2017, giving it a veneer of scientific respectability that it did not deserve. Some anti-abortion politicians in the USA, who weren’t apparently concerned about the lack of evidence, put laws through the national legislatures of eight US states requiring doctors to offer “abortion pill reversal” to any woman who had taken mifepristone, but not yet taken the misoprostol 24 hours later (if she changed her mind). I wrote a comment criticising the article, which was published in April 2018: Response to “Progesterone for preventing pregnancy termination after initiation of medical abortion with mifepristone”: what’s the real point here? Eur J Contracept Reprod Health Care 2018 Apr;23 (2):169. The original article was not removed but “corrected”.

Both health professionals and women need medically accurate information. Anti-abortion politicians have been trying to interfere in the relationship between abortion care providers and their patients for years. If you want to see the extent to which the “reversal” movement has sought to influence women with unwanted pregnancies in the USA, go to Google, click on “images”, type in “abortion pill reversal” and scroll down and down and down some more.

US abortion providers and abortion rights advocates debated how to address this problem for a long time. Lousy science was bad enough; but the need to challenge state laws that made “reversal” an option that had to be discussed in mandatory pre-abortion counselling, without evidence that it is safe or effective, was far worse. It was finally decided that rather than simply reject the weak evidence because it was not credible, it was necessary to do the research and prove whether the claims were correct or not. Dr Mitchell Creinin, professor of obstetrics and gynaecology at University of California at Davis, was the lead researcher on the study.

The study was designed as a double-blind, placebo-controlled, randomised trial with 40 patients who were scheduled to have surgical abortions. The aim was to test the effectiveness of “abortion pill reversal”, that is, whether taking a high dose of the oral hormone progesterone can stop a medical abortion after a patient has completed the first part (mifepristone) of the two-step (mifepristone + misoprostol) process. They enrolled participants from February to July 2019, but stopped enrolment early, after 12 patients, because of safety concerns. This is what happened:

Mean gestational age was 52.5 days. Before their surgical abortion procedures, the women received mifepristone. They were then randomly assigned to receive either a placebo or progesterone. The study was stopped because three women required ambulance transport to a hospital for treatment of severe vaginal bleeding. Of the three, one had taken progesterone after mifepristone; two had taken a placebo.

The researchers decided the risk to women of participation was too great to continue with the study. Dr Creinin said: “Encouraging women not to complete the [mife+miso] regimen should be considered experimental… We have some evidence that it could cause very significant bleeding.” Because the study was stopped, it was unable to show what, if any, effectiveness progesterone has in reversing a medical abortion. But it did find evidence that use of mifepristone alone could cause harm – in the form of very significant bleeding. Hence, there is even more reason to reject suggestions to try “reversal”. Instead, women need to be sure they want an abortion before they use the pills.

PS. The safety and effectiveness of mifepristone + misoprostol for medical abortion has not been questioned or challenged in any way by any of this research.

SOURCES: National Public Radio, 5 December 2019 ; Obstetrics & Gynecology (abstract only ahead of publication), 5 December 2019, DOI: 10.1097/AOG.0000000000003620 ; PHOTO: Grandmothers for Reproductive Rights, @GRRNow, 13 February 2018