A medical abortion is one that is brought about by taking medications that will end a pregnancy.

The alternative is surgical abortion which ends a pregnancy by emptying the uterus (or womb) with special instruments. Go to First Trimester Abortion and Second Trimester Abortion pages.

A medical abortion usually is done without entering the uterus. Either of two medications, Methotrexate or Mifepristone (RU486), can be used for medical abortion. Each of these medications is taken together with another medication, Misoprostol, to induce an abortion.

Determination of Length of Pregnancy

Before any abortion can be done, a medical professional must confirm that a woman is indeed pregnant and determine exactly how long she has been pregnant.

The length of a pregnancy is usually measured by the number of days that have passed since the first day of the woman's last menstrual period (abbreviated as LMP). Medical abortions can be performed as early as a pregnancy can be confirmed. In fact, the shorter the time that a woman has been pregnant, the better the medications will work. Because they do not work as well later in pregnancy, medical abortion is often not an option after nine weeks (or 63 days) LMP. After that, surgical abortion may be the safest and best option.

How the Medications Work

• Methotrexate - Methotrexate has been used in the US since 1953, when it was approved by the FDA to treat certain types of cancer. Since that time, medical researchers have discovered other important uses for the drug. One of these uses is to end unintended pregnancies. Although the FDA did not consider methotrexate for this specific purpose, clinicians may prescribe (and are now prescribing) methotrexate for early abortion. 

  Methotrexate usually is given to a pregnant woman in the form of an injection, or shot, although it can be taken orally. Methotrexate stops the ongoing implantation process that occurs during the first several weeks after conception.

• Mifepristone - Another medication that might be used is mifepristone. Mifepristone, also called RU486, is a newer medication that was developed and tested specifically as an abortion inducing agent. It has been used by over 500,000 women in Europe and millions of women worldwide, especially in China.
• Mifepristone is taken in the form of a pill. It works by blocking the hormone progesterone, which is necessary to sustain pregnancy. Without this hormone, the lining of the uterus breaks down, the cervix (opening of the uterus or womb) softens, and bleeding begins.
• Misoprostol - A few days after taking either methotrexate or mifepristone, a second drug, misoprostol, is taken. Misoprostol tablets, which can be taken orally or put into the vagina, cause the uterus to contract and empty. This ends the pregnancy.

Methotrexate and Mifepristone work in different ways, and so they will have slightly different effects on a woman's body. A clinician can help a woman decide whether medically induced abortion is the right option for her, and which of the two drugs she should use.

How Long Do Medical Abortions Take?

Medical abortion can take anywhere from 3 days to 3-4 weeks, and requires a minimum of two visits to the clinic or medical office.

The return visits are very important since there is no other way to be sure that the abortion has been completed. With methotrexate, 80-85% of women will abort within two weeks. Some will take longer and may need more doses of misoprostol. With mifepristone, 95-97% of women will abort within two weeks. About 1 in 20 women who try medical abortion will need to have a surgical abortion because the medication does not work for her.

During and After a Medical Abortion

Some women will have vaginal bleeding after the first drug. This bleeding may be light, or it may be like a heavy period.

The abortion provider may have the woman stay at the clinic for several hours after taking the second drug (misoprostol). The uterine contractions caused by this medication may lead to immediate cramping that will expel the embryo, thus ending the pregnancy. A high proportion of women, however, will expel the uterine contents later, after they have left the medical facility. Many women insert the misoprostol at home and pass the tissue later. A woman considering medical abortion will need to be prepared for this possibility. The clinic staff can answer questions about what to expect.

The most common side effects of medical abortion are caused by misoprostol, the medication taken after the methotrexate or mifepristone. The side effects may include: cramps similar to those with a heavy menstrual period, headache, nausea, vomiting, diarrhea, and heavy bleeding.

The amount of bleeding that a woman has will be greater with medical abortion than with surgical abortion. Most women have cramps for several hours, and many pass blood clots as they are aborting. In some cases, the blood clots will be larger than the embryo and other tissue from the pregnancy which will also be passed, and the embryo will probably not be seen among the blood clots. For example, at 49 days LMP, the size of the embryo will be about one-fifth of an inch. In an earlier pregnancy, it might be much smaller than that. Cramps and bleeding usually begin to ease after the embryonic tissue has been passed, but bleeding may last for one to two weeks after medical abortion.

Some women report that their first regular menstrual period after a medical abortion is heavier, or longer, or in some other way different from normal for them. By the second period after the abortion, their cycles should be back to normal.

Possible Complications

Medical abortion is irreversible once the mifepristone or methotrexate has been taken.

Deciding to continue the pregnancy to term is not an option at any point after taking the first medication. If the embryo is not expelled after using these medications, a suction procedure (surgical abortion) must be done to empty the uterus and complete the abortion. See First Trimester Abortion and Second Trimester Abortion  pages.

The most common immediate complication of a medical abortion is heavy bleeding. For this reason, a woman must have access to a telephone and transportation in case emergency treatment is needed. Rarely, just like with surgical abortion, treatment for very heavy bleeding might require a D & C or a blood transfusion.

There do not appear to be any long-term complications associated with use of these drugs to induce a medical abortion.

Follow-up Care

Because there is no way to know for sure that the abortion is complete without an examination by a health care professional, keeping appointments with the clinic for follow-up care is very important!

In addition, a woman must report any problems she has during the medical abortion to a health care professional.

Anti-Abortion Propaganda About Medical Abortion

Anti-abortion activists claim that medical abortion is unsafe for women, even though the evidence confirms that medical abortion is both safe and effective.

The real goal of those activists is to stop all types of legal abortion - a situation which would put the lives and health of women in danger. When abortion was illegal in the United States (from the late 1800s until 1973), more pregnant women died from complications from self-induced abortions or abortions performed by untrained practitioners than from any other cause. Today, abortion is one of the most common and safest procedures in medicine. Because earlier abortions are the safest, medical abortion is an important medical advance for women, and an option that many will choose.