| Procedure |
How it Works |
Advantages |
Disadvantages |
| Mifepristone |
Mifepristone, taken orally, blocks the action of progesterone, which causes the uterine lining to thin and the pregnancy to detach. It also causes the cervix to soften and dilate, and increases the production of prostaglandins, which cause uterine contractions. Misoprostol, a prostaglandin analogue taken either orally or inserted vaginally within a few days of mifepristone, induces uterine contractions and increases the effectiveness of mifepristone to approximately 95-98%. |
- Usually avoids the use of surgical instruments, thus avoiding the risk of injury to the cervix or uterus from instrumentation.
- Anesthesia not required.
- High success rate (95-98%).
- Resembles a "natural miscarriage."
- May offer women more privacy.
- Both drugs can be administered orally.
- Can be used very early in pregnancy.
- Procedure completed within 24 hours of the misoprostol administration in 90% of women.
- Approved by the FDA for early abortion. |
- Requires at least 2 visits.
- Effectiveness decreases with use after 7 weeks in regimens using oral misoprostol. Efficacy remains high up to 9 weeks with vaginal misoprostol.
- Takes days or, rarely, weeks to complete.
- Post-procedure bleeding may last longer than with surgical abortion.
- Women may see blood clots and pregnancy tissue. |
| Methotrexate |
Methotrexate, given by injection, or occasionally orally, stops the ongoing process of implantation of an early pregnancy. Misoprostol, a prostaglandin analogue inserted vaginally several days after the methotrexate, causes uterine contractions and increases the effectiveness of methotrexate to approximately 95%. |
- Usually avoids the use of surgical instruments, thus avoiding the risk of injury to the cervix or uterus from instrumentation.
- Anesthesia not required.
- High success rate up to 7 weeks (95%).
- Resembles a "natural miscarriage."
- May offer women more privacy.
- Can be used very early in pregnancy.
- Can be used to treat ectopic pregnancy.
- Methotrexate and misoprostol are both FDA-approved for other uses. |
- Requires at least 2 visits.
- Effectiveness decreases with use after 7 weeks.
- May require several doses of misoprostol.
- Takes several days or weeks to complete.
- Post-procedure bleeding may last longer than with surgical abortion.
- Women may see blood clots and pregnancy tissue. |
| Vacuum Aspiration |
Cervix is gradually opened with tapered rods. A cannula (straw-like tube), which is attached to a suction apparatus (either an electric machine or hand-held syringe), is inserted through the cervix into the uterus. The contents of the uterus are emptied by suction. Vacuum aspiration is approximately 99% effective. |
- Usually only requires one visit to the provider.
- Procedure is usually completed within minutes.
- Allows for sedation if desired.
- High success rate (approximately 99%).
- Can be used early in pregnancy. |
- Involves a surgical procedure.
- May seem less private to some women than aborting at home. |
Adapted from a joint NAF and Abortion Access Project of Massachusetts fact sheet.
