What is it used for and how does it work?
One use for Mifepristone is the termination of pregnancy under 49 days gestation. In medicine, this is called medication abortion or medication termination.
The hormone called progesterone sustains a pregnancy. Mifepristone works by blocking progesterone which causes
- Changes in the lining of the uterus
- The detachment of the pregnancy from the wall of the uterus
- A softening and opening of the cervix
This process often stops the pregnancy.
In medication abortion, Mifepristone (or RU486) is often used with another drug called misoprostol. The second drug also softens the cervix and causes the uterus to contract so that a pregnancy which has been stopped by misoprostol can leave the woman’s body more readily.
What is the procedure for a medication abortion?
Different clinics and doctors have different procedures for medication abortion so this information is just a general guide:
First, you will attend the doctor or clinic able to provide medication abortions. Your pregnancy will be dated and your medical history discussed to assess any medical reasons why you should not use Mifepristone. The procedure of medication abortion will be explained and you will be asked to give your consent to treatment. You will swallow the Mifepristone tablets.
Two days later, if the abortion has not occurred, you will use the Misoprostol tablets which are either swallowed or inserted into the vagina (your doctor will tell you how to use the tablets).
Between 12-19 days later the doctor will assess whether the abortion is complete. A ‘complete abortion’ means the pregnancy has stopped growing and all pregnancy tissue has left the woman’s body. If it is found that the pregnancy is continuing then a surgical abortion will most likely be recommended by the doctor. If some pregnancy tissue remains within the uterus the doctor will discuss your options for treatment with you.
It is absolutely critical for all women who have chosen medication abortion to return to the doctor for this assessment, your doctor must ensure the abortion is complete.
Some of the figures around use of Mifepristone for medication abortion
- 95% of women have a complete abortion
- 5% of women have to have further treatment (1% due to ongoing pregnancy and 2%-4% for incomplete abortion)
- 64% of women have a complete abortion within 4 hours of using Misoprostol (the second medication)
- 90% of women have a complete abortion within 24 hours of using Misoprostol
- There may be some vaginal bleeding for an average of 10-16 days after a medication abortion
- 40%-70% of women experience nausea, 10%-45% of women experience vomiting and 10%-30% of women experience diarrhea when using Misoprostol
- It is estimated that <1% of women experience serious infection rates