A briefing from DfC/UK, by Sean Rees



A recent openDemocracy investigation has shown that rightwing Christian anti-abortion activist groups based in the US are supporting doctors in the UK to prescribe the so-called “abortion-reversal pill” (ARP). This practice is not currently supported by medical science and is not endorsed by any authoritative national or international best-practice guidelines.

Those who promote the use of progesterone as an ARP rely on the results of poorly-conducted research published in anti-choice ‘pseudo-journals’, and ignore the safety concerns of subsequently published and more robustly designed trials. This is an experimental treatment and should only be prescribed in human clinical trials. 

This is an egregious example of doctors using their privilege and position to take advantage of patients by pushing their anti-abortion ideology on women in sometimes vulnerable and distressing situations; in place of compassion for women and their choices is a commitment to a broader project that seeks ultimately to deny women any semblance of agency that requires shocking tactics in dehumanising those who seek and provide abortions. It is unsafe and unethical medical practice.


What is a medical abortion?

Early medical abortion (EMA) involves two pills: mifepristone and then, 24-48 hours later, misoprostol. The use of these pills in ending pregnancies is very safe and recommended by a wide range of national and international guidelines (including the UK-based National Institute of Health and Care Excellence (NICE) and the Royal College of Obstetricians and Gynaecologists (RCOG)). Most abortions in the UK are medical abortions with pills (in 2019: 73% of all abortions in England and Wales; 88% in Scotland). 

Mifepristone is a progesterone blocker and stops the pregnancy growth, but also enhances the effect of misoprostol; misoprostol makes the uterus contract to complete the abortion. Medical abortions are most effective when both pills are taken; mifepristone alone will often, but not always, end the pregnancy. When mifepristone alone is taken, there is a reasonable chance (8-46%) of the pregnancy continuing. As such, a significant percentage of those who stop medical abortion treatment after taking mifepirstone will have continuing pregnancies without any further intervention (although they are at a higher risk of pregnany loss).



The percentage of medical abortions in England and Wales in 2019


The percentage of medical abortions in Scotland in 2019


What is the "abortion reversal pill"?

The concept of an “abortion-reversal pill” comes from the US, where extremist anti-abortion organisations promote the use of high-dose progesterone as a way of halting the effects of mifepristone (an anti-progesterone) and allowing a pregnancy to continue. To be clear: this is not evidence-based and does not meet clinical standards; there is no national or international authoritative medical body or guideline that recommends this ‘treatment’.


Unsafe practice

A systematic review found no credible evidence that using progesterone after ingestion of mifepristone is better than expectant management in assuring a continuing pregnancy and that “to suggest otherwise is scientifically untenable”. 

The review found only one case series that met inclusion criteria that sought to assess the effectiveness of medical abortion reversal:

  • This case series is often quoted by those who are anti-choice to support the use of progesterone as an ARP, but the study is of poor quality, with few details provided in the publication; indeed, case series with no control group are among the weakest forms of medical evidence.

  • The journal in which this case series was published, Issues in Law and Medicine, has previously been shown to be “created, edited, published, and disseminated by the anti-choice movement”.

  • Issues is one of a growing number of “predatory” or “pseudo-journals”, a classification given by the International Committee of Medical Journal Editors (ICMJE) to ‘journals’ that do not meet accepted publishing standards. 

  • Issues is not recognised by the ICMJE, and is not a member of the Committee on Publication Ethics. 

A randomised-controlled trial published in 2020 had to be stopped due to safety concerns for trial participants. The trial was aiming to assess the efficacy and safety of using progesterone to antagonise the effects of mifepristone during a medical abortion, but participant enrollment stopped after 12 patients due to “severe hemorrhage requiring ambulance transport to hospital” in three patients. The authors of the trial concluded that the use of progesterone to antagonise the effects of mifepristone should be considered “experimental” and should only be prescribed in “approved human clinical trials to ensure proper oversight”.

It is a moral, as well as clinical, imperative to base clinical care on the available evidence, and so to promote the use of progesterone as an effective method of medical abortion reversal based on one poor quality case series is at best disingenuous and at worst dangerous to women.


Unethical practice

There are two main concerns that, if substantiated, would represent unethical medical practice. 

Firstly, it is not clear that the doctors to whom women are directed when enquiring about an abortion reversal pill are: offering non-judgemental and non-directive counselling; informing their patients about all management options available to them (i.e. that there is a significant chance that mifepristone alone will not end a pregnancy); or being transparent about the experimental nature of this treatment. To ensure ethical medical practice, prescribing medications for uses that are not evidence-based requires a robust consultation to ensure informed consent. Given the safety concerns of previous trials, the use of progesterone to reverse medical abortions should only take place within human clinical trials with ethical oversight and robust design. 

Secondly, this ‘treatment’ is not available on the NHS and so patients are seeking out doctors willing to prescribe this drug outside of formal healthcare services. The openDemocracy investigation found that, following internet searches, women can contact a US-based anti-choice group that signposts women to UK-based doctors willing to prescribe so-called abortion reversal pills. By facilitating this convoluted way of accessing medications for experimental usage, these anti-choice doctors are taking over the care of patients without appropriate handover and a lack of accountability whilst removing them from formal healthcare services that can offer non-judgement and non-directive counselling and have proper safeguarding procedures in place. Given the clear anti-choice ideology that drives those who are quoted as researchers, those who promote, and those who prescribe ARPs, there are concerns that these doctors are taking advantage of vulnerable patients by using experimental and potentially dangerous treatments to impose their anti-choice views.