Catholic Medical Quarterly

The Journal of the Catholic Medical Association (UK)

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Catholic Medical Quarterly Volume 75(4)  November 2025

Abortion Pill Reversal

Dr Dermot Kearney

Introduction

In many jurisdictions where induced abortion is allowed, the majority of abortions are now carried out by chemical, rather than surgical, means. In England and Wales, drug-induced abortions accounted for 86% of the total number of 252,122 abortions reported in 2022. [1] In Scotland, 99% of 16,607.abortions reported in 2022 were carried out by chemical means.[2] It is estimated that 63% of induced abortions in the USA in 2023 were drug-induced. ^[3]

The drugs most commonly used to induce abortion are Mifepristone and Misoprostol in combination. This regimen has been used to induce abortion in the UK since 1990, having been first approved for use in France one year earlier. The drugs received Food and Drug Administration approval for induction of abortion in the USA in 2000.

Mifepristone is administered first. The recommended single dose in the UK and in the USA is 200mg. Higher doses of 600mg are used in some other jurisdictions, most notably in several other European countries. Mifepristone is a specific Progesterone receptor blocker. By competing with natural endogenous Progesterone for Progesterone receptor sites in the female reproductive tract, Mifepristone blocks the action of the natural hormone Progesterone that is essential to maintain pregnancy by maintaining the integrity of the endometrium, the lining of the womb.

A common cause of spontaneous miscarriage in early pregnancy is a low level of natural Progesterone. Mifepristone, by blocking the action of Progesterone, effectively induces an artificial mimicking of a low Progesterone state. By blocking the natural Progesterone effect, Mifepristone thereby frequently induces miscarriage by interfering with the natural process of essential changes to endometrial cells in preparation for, and during, pregnancy, a process known as decidualisation. This interference causes shedding of the endometrium to which the developing embryo or fetus is attached. Mifepristone therefore, when effective, cuts off essential blood, nutrient and oxygen supplies to a developing embryo or fetus.

The second drug employed in drug-induced abortions, Misoprostol, is taken 24-48 hours after the administration of Mifepristone, in order to complete the intended abortion and emptying of the uterus. It is a Prostaglandin analogue that induces intense contraction of the uterine muscle cells. The recommended dose of Misoprostol for abortion induction in the UK and USA is an initial dose of 800 micrograms with additional doses of 400 micrograms if necessary to complete the abortion.

Abortion Pill Reversal using Progesterone

Some mothers, during pregnancy, change their minds about continuing with a planned abortion, even after they have taken the first abortion pill, Mifepristone. Although Mifepristone per se is very effective in inducing miscarriage, there is a window of opportunity whereby the lethal effect of the drug on the developing child can sometimes be prevented and its effect reversed by offering bioidentical Progesterone therapy. This use of Progesterone is known as Abortion Pill Reversal (APR) treatment.

Just as Mifepristone can block the natural effects of endogenous Progesterone by competing for Progesterone receptors, similarly exogenously-administered Progesterone can act as the natural antidote to the potentially poisonous effect of Mifepristone by competing for those same receptor sites, allowing the life-saving and pregnancy-maintaining effect of Progesterone to continue.

Three possible options face a mother after she has taken the first abortion pill, Mifepristone, to induce abortion.

1. She may continue with the abortion process and take the second abortion-inducing pill, Misoprostol, 24-48 hours later, as instructed by the abortion providers. This happens in the vast majority of drug-induced abortions. When both Mifepristone and Misoprostol are administered, there is a 98% chance the baby will be killed by induced abortion. [4]
2. If she has taken Mifepristone but doesn’t take Misoprostol and doesn’t receive Progesterone rescue therapy, there is an 80% chance her baby will die by abortion. [4]
3. If she has taken Mifepristone, doesn’t take Misoprostol and promptly receives rescue treatment with Progesterone and continues the rescue treatment, there is a 50-68% chance her baby will survive. [5,6]

In our UK experience, with more than 70 reversal successes to date, APR has a rate of successful antagonisation of Mifepristone in 50-60% of cases. [6] Studies from the USA have demonstrated 64-68% success rates. [5] Likely explanations for the difference in success relates to a greater awareness of the service in the USA and a greater number of APR providers relative to the UK. Rescue treatment is delivered in a more timely manner in the USA. Furthermore, in many US centres, immediate ultrasound examinations can often be obtained to assess whether or not the developing child is still alive after Mifepristone has been administered. This is rarely possible in the UK where APR is started blindly with the hope that the child may still be alive.

APR therapy more than doubles the chance of a baby surviving after a mother received Mifepristone relative to expectant management alone when no rescue Progesterone is administered.  Looked at another way, APR using Progesterone reduces a certain mortality rate of 80% for a developing child exposed to Mifepristone to less than 50%. Very few other interventions in medicine can achieve this remarkable certain mortality risk reduction.

The success of APR appears to be dependent on a variety of factors including the stage of gestation at which Mifepristone was administered and the delay in the initiation of Progesterone rescue treatment. [5] The method of Progesterone administration also appears to be an important factor. One large observational study demonstrated higher success rates with oral and intramuscular administration of Progesterone relative to vaginal pessary administration. [5] It is possible that other factors may also be important in determining success rates such as the general health of the mother and the presence or absence of other medical conditions, previous obstetric history, maternal age, maternal body mass index and educational and socio-economic factors. [6]

Since the APR Network programme was established formally in the USA in 2012, more than 7000 babies have already been saved by mothers seeking the service. [7] Importantly, there is no evidence of any increased risk of congenital defects for babies who have been saved, despite early exposure to Mifepristone. [5] It is apparent that Mifepristone either ends the life of the developing child at an early stage after administration during pregnancy or has no long term effects whatsoever.

Progesterone, furthermore, has been used in pregnancy for more than fifty years and is widely recommended for helping to reduce the risk of miscarriage in mothers who are perceived to have an increased risk of miscarriage in early pregnancy. It is also used routinely in in-vitro fertilisation to help maintain pregnancy. [8]

APR Process in Practice

When a mother wishes to seek help with APR to try to save her baby after regretting that she has taken Mifepristone, she can do so in a variety of ways. She may contact the 24/7 international APR network helpline and a trained nurse will arrange care for her with an APR-providing physician in her area. Alternatively, she may be able to contact a local pregnancy help centre or prolife organisation directly that can readily find a local APR provider for her.

The APR provider, following a detailed discussion and after obtaining her fully-informed consent to initiate rescue treatment, arranges for her to receive emergency Progesterone therapy. The recommended protocol, commenced as soon as possible after Mifepristone, involves the administration of micronized Progesterone 400mg twice daily for three days followed by 400mg daily for at least a further two weeks. Micronised Progesterone can be administered by oral capsules (Utrogestan in the UK) or vaginal pessaries (Cyclogest in the UK). In some jurisdictions, intramuscular Progesterone injection regimens may also be available.

Whichever APR regimen is used, the aims are to counteract the potential harmful pharmacological effects of Mifepristone, preserve pregnancy and protect the developing child to at least 13 weeks gestation. By the start of the second trimester, the placenta is usually capable of producing sufficient quantities of natural endogenous Progesterone to maintain pregnancy.

While APR is effective in preserving pregnancy in more than 50% of cases when commenced within 72 hours of Mifepristone administration, provided heavy bleeding or severe abdominal cramps have not commenced, it is vital to start treatment as soon as possible. The earlier rescue treatment is commenced, the higher the chances of a successful outcome. [5,6]

Opposition to APR

Despite the life-saving efficacy of APR and the excellent safety record associated with the treatment, there is a widespread lack of awareness of the availability and the benefits of the service among the general population. In addition, from the very start of its existence, APR has attracted strenuous opposition, primarily from abortion providers and abortion promoters. [9]

Opponents initially claimed that women rarely changed their minds about continuing with abortion after taking Mifepristone. It was later claimed that APR was no more effective than expectant management alone in allowing for continuing pregnancy after administration of Mifepristone and before Misoprostol. [9]

When it became clear that these claims of a lack of demand and a lack of efficacy of APR were untrue, [5] a new claim of a potential “danger” of APR was fabricated and propagated by abortion providers. A very small study published in 2020 has been used to support this claim. [10]

The “study” was designed by Mitchell Creinin, an abortionist from California and an early outspoken critic of APR. He was determined to design a “study that can be definitive” to demonstrate that APR was “junk science”. [11]

The design of this “study” merits consideration. It was described as a “Randomized Controlled Trial” yet was not controlled. It was decided that only 40 subjects would be required for the trial to demonstrate a superior efficacy of APR over “expectant management” if such a superiority actually existed. With such small numbers, concerns arise that the “study” was designed to demonstrate an absence of superiority. No attempt was made to “control” for relevant factors that might influence outcomes such as maternal age, previous obstetric and medical histories, concomitant medications, BMI, socio-economic factors and even the gestational stage of pregnancy. It cannot therefore be described as a Randomised Controlled Trial but rather as a poorly-designed randomised trial.

Despite the design, the “study” proceeded. It was planned to recruit 40 mothers who had taken Mifepristone to induce abortion in early pregnancy. From this cohort, 20 would receive oral Progesterone 24 hours later and 20 would receive placebo. None would receive Misoprostol. They would be followed up to 15 days after the administration of Mifepristone. If they were still pregnant at that stage, they would be offered surgical abortions.

In total, 12 mothers were recruited to participate before the study was discontinued. Of these, 6 were assigned to the APR group receiving oral Progesterone and 6 were assigned to the placebo group. Following randomisation, 2 mothers withdrew from the study within a matter of days and proceeded to abortion. One withdrew from each of the two groups. The “study” was discontinued ahead of schedule after these 12 mothers had been recruited. The results from the remaining 10 participants demonstrated that 4 of the 5 mothers who had received Progesterone after Mifepristone were still pregnant with viable pregnancies at the 15 day mark. Among those who had received placebo (expectant management), only 2 out of 5 were still pregnant. This represented a doubling of the survival rate for babies whose mothers had received APR relative to the survival rate for babies whose mothers did not receive Progesterone. In addition, 2 of the 5 mothers in the placebo group needed emergency hospitalisation with severe haemorrhage. One of these required a blood transfusion and the other required emergency surgical intervention. Of the 5 mothers who received Progesterone, 1 required an emergency attendance due to heavy bleeding. Following assessment, she was discharged from hospital without the need for any intervention. She did not suffer any significant reduction in her haemoglobin level and she remained haemodynamically stable.

This small study demonstrated that Progesterone administered 24 hours after Mifepristone was more effective in preserving pregnancy and also reduced the risk of serious maternal haemorrhage when compared to expectant management alone after Mifepristone administration.

Despite these outcomes, the authors incredibly concluded there was no evidence to demonstrate superiority of APR over expectant management and that APR might represent a danger to women who have taken Mifepristone as it might lead to severe haemorrhage. They stated that the “study” was discontinued due to “safety” concerns. For any neutral observer, however, it might be considered that the early discontinuation could be related to the authors’ dissatisfaction with what was demonstrated after only 12 participants had been recruited. The “study” was not supposed to demonstrate that APR was not only more effective but also safer than expectant management alone.

Conclusion

In summary, APR using Progesterone is widely available, is safe for both mother and child and is often effective in saving lives. When administered promptly after Mifepristone and continued for at least 2 weeks, APR more than doubles the chance of babies surviving despite exposure to Mifepristone in early pregnancy. There is no increased risk of any congenital malformations for babies who survive. More than 7000 babies (from 2012 to June 2025) whose mothers availed of APR services have already been born.

For those who need help in accessing abortion pill reversal, the Abortion Pill Reversal Network provides worldwide help 24/7 and can be accessed on abortionpillreversal.com