Vaginal bleeding and uterine cramping are expected effects of
medication abortion methods and are the result of the abortion process.
Additionally, there are a number of common side effects associated with the
medications used in the medication abortion regimens. The type of
side effect and the severity of the side effect varies by regimen. The following table
lists the most common side effects reported in selected US trials
of medication abortion regimens.[1]
Percentage of women reporting the
symptom (by regimen)
|
Side effect
|
Mifepristone and misoprostol
|
Methotrexate and misoprostol
|
Misoprostol alone
|
| Nausea |
36-45%
|
19-47%
|
12-43%
|
| Vomiting |
13-14%
|
9-12%
|
8-45%
|
| Diarrhea |
8-11%
|
7-22%
|
7-67%
|
| Headache |
14-18%
|
13-16%
|
12-27%
|
| Dizziness |
15-22%
|
14%
|
18-37%
|
| Fever, chills
warmth,
hot flashes |
14-20%
|
15-43%
|
31-89%
|
For most women these side effects are tolerable. Many of these side effects can be reduced by using
non-prescription pain medications (such as ibuprofen) or anti-emetics
(anti-nausea medications).
Complications from medication abortion regimens are
relatively rare and include prolonged bleeding, incomplete abortion, and ongoing pregnancy. The rate of complications depends
on the specific regimen used. For the mifepristone and misoprostol regimen, approximately 2%-5% of cases will require an aspiration
intervention to control bleeding or complete the abortion. About 0.1% of women using the mifepristone and misoprostol regimen
will require a transfusion.
For the methotrexate and misoprostol regimen, less than 1% of women will require an intervention for excessive
bleeding. For women with pregnancies of seven weeks or less, about 5% will require an aspiration intervention to complete the
abortion process.
Of all of the medication abortion regimens, the misoprostol alone regimen carries the greatest risk of complications. When used
in the first nine weeks of pregnancy, misoprostol alone has an efficacy of 75%-85%. In approximately 15%-25% of cases, the
abortion is incomplete
or the pregnancy is ongoing and either an additional dose of misoprostol or an aspiration intervention is required.
Recent studies suggest that the ongoing pregnancy rate after
administration of misoprostol for early pregnancy termination is
approximately 10%. Prolonged or
excessive bleeding requiring additional intervention includes in less than 5% of cases.
Reference: ACOG
Practice Bulletin. 2001; no. 26.
