Just In Case
Regular readers of this blog know that I am unequivocally opposed to politicians [irrespective of party affiliation] making medical decisions for women. So, just in case people you've never met [but might have voted for] decide to no longer permit you to make life and death health decisions, I thought it prudent for us to briefly review the topic of medical termination of pregnancy. A couple of points, before we start:
Medical termination of pregnancy (MTP) refers to non-surgical methods of terminating a pregnancy. Instead of a surgical procedure, various drugs are used to terminate the pregnancy. The drugs used for MTP end an already established pregnancy, thus they are abortifacients (they cause an abortion). [By contrast, drugs used for birth control prevent a pregnancy and have no effect on an established pregnancy.]
There are many drugs and regimens used for MTP. Only 3 of these drugs are routinely used for early terminations, meaning pregnancies up to 9 weeks (63 days): misoprostol, mifepristone (RU-486) and methotrexate. [Yes, I know, the drug names sound awfully similar ... not a good idea.]
An aside: the early MTP drugs are often confused with drugs used for birth control, especially with drugs used for emergency contraception (EC). They are not one and the same--the mechanisms of action involved are completely different. Abortifacients terminate a pregnancy. Birth control prevents it.
Before we review the individual drugs, there is one very important point you must remember. Although the early pregnancy termination drugs are easy to use and to self-administer, you should only use them under close medical supervision. Why? Because these drugs act on an already established pregnancy. A pregnancy, even an early one, can be associated with potentially deadly complications, like an ectopic.
This is in contrast to drugs used for EC that act before there is a pregnancy; this makes them safe to use without a prescription, or over-the-counter.
There are 6 main groups of MTP drugs:
Oxytocin is a drug that causes uterine contractions and induces labor. High doses of oxytocin are given in small volumes of intravenous fluids.
2. HYPEROSMOTIC SOLUTIONS
Hyperosmotic solutions also induce labor. For example, 20-25% saline or 30-40% urea solutions are injected into the amnionic sac (the bag of fluid).
3. PROSTAGLANDINS AND ANALOGUES
Prostaglandins are substances naturally produced in the body. They have many actions, including induction of labor. The drugs in this group can be used vaginally, as a shot, into the amnionic sac, and orally (by mouth).
Misoprostol belongs to this group. The brand name in the U.S. is Cytotec and it is used to induce labor, to treat stomach ulcers, etc.
Antiprogesterones are drugs that block the action of the body's hormone progesterone. Progesterone is very important for pregnancy.
Mifepristone (RU-486), a pill, is a drug in this group. The brand name in the U.S. is Mifeprex.
An aside. The amount of incorrect information about mifepristone (RU-486) is staggering. Unless you know the actual facts about this drug, it is impossible for you to make an informed medical decisions. Briefly: mifepristone is *not* an abortifacient (an "abortion pill"), it *is* an antiprogesterone. What's the difference? A crucial one: the mechanism of action, the way the drug works. [Important for you to understand this: what people decide to call mifepristone--"the devil's pill" or "the fluffy bunny pill"--is irrelevant. Its mechanism of action is the same, regardless.]
By definition, an "abortion pill" causes an abortion, meaning it terminates an already established pregnancy. An "abortion pill" has no mechanism by which to prevent a pregnancy from becoming established. A good example is the drug misoprostol. The only mechanism of action of this drug is to induce labor. So, this drug has no way of preventing a pregnancy; it can only terminate one. Misoprostol is an abortifacient.
Contrast this with the mechanism of action of mifepristone (RU-486). Mifepristone can either block the release of the egg from the ovary, block implantation, or cause the lining of the uterus, together with an implanted egg, to shed. So, this drug can either prevent a pregnancy, or terminate one. Mifepristone is an antiprogesterone. It can be used as birth control, or as an early pregnancy termination drug. [Obviously, the dosage and regimen vary.]
Back to our discussion. When mifepristone is used for MTP, the dosage/regimen used causes the lining of the uterus, together with the implanted egg, to shed.
5. PROGESTERONE PRODUCTION BLOCKERS
Progesterone production blockers, as the name implies, block the production of the hormone progesterone. Progesterone is very important for pregnancy.
Epostane, a pill, is an agent in this group. The usual dose is 200 mg every 6 hours, for 7 days, and you can take it up to 7 weeks (49 days) from the date of your last normal menstrual period. The rate of successful treatment with epostane is 87% - 90% , and it has a good safety profile. The main side effects are nausea and vomiting. The average length of vaginal bleeding with this regimen is 10.7 days. Once the treatment is complete, usually there is no delay in the resumption of normal periods.
Methotrexate is a folic acid antagonist, a drug that stops cells from dividing. It comes in the form of a pill, or a shot.
Remember, only three of the aforementioned drugs--misoprostol, mifepristone (RU-486) and methotrexate--are used for early MTP. [Epostane can also be used, but this is an older regimen, not in common use today.]
|Regimen||MIFEPRISTONE & MISOPROSTOL||METHOTREXATE & MISOPROSTOL||Comments|
|How does it work?||Mifepristone: blocks the action of progesterone, causing the uterine lining to thin and detach.|
Misoprostol: causes uterine contractions that expel the embryo and placental tissue.
|Methotrexate: stops cell division.
Misoprostol: causes uterine contractions that expel the embryo and placental tissue.
|When does it work?||1. Evidence-based: through 9 weeks (63 days) from the last menstrual period (LMP)|
2. FDA-approved: through 7 weeks (49 days) from the LMP
|Once pregnancy is confirmed, through 7 weeks (49 days) from the LMP||
|Dose||1. Mifepristone 200 mg
by mouth, followed 1-3 days later by Misoprostol 800 mcg vaginally (self-administered, at home)
2. Mifepristone 600 mg by mouth, followed 2 days later by Misoprostol 400 mcg by mouth
|Methotrexate 50 mg by mouth or a 50 mg/m2
shot, followed 3-7 days later by Misoprostol 800 mcg vaginally (self-administered, at home)
|How well does it work?||1. ~97%|
2. 92% to 97%
|94% to 96%||If the drugs are unsuccessful, surgery is needed to complete the process.
|How many office visits?||1. Two|
|Two||Depending on the individual case, more visits may be needed.
|Side effects||Nausea, vomiting, diarrhea, headache, dizziness, fever or chills, anemia (rare), blood transfusion needed (rarely).||Nausea, vomiting, diarrhea, headache, fever or chills, stomatitis (rare), anemia (rare), blood transfusion needed (rarely).||Bleeding and cramping are expected effects of all termination procedures.
|Expected bleeding||~ 13 days||~ 10-17 days||
|Can it treat an ectopic?||Not an effective treatment.||~ 90% effective for early, unruptured ectopic (3.5 cm or less, initial beta hCG less than 5,000 mIU/ml).||An ectopic pregnancy can be deadly. This is why the supervision of a qualified doctor is imperative.
|Follow-up||Must return to confirm termination is complete. If it isn't, surgery is necessary.||Must return to confirm termination is complete. If it isn't, surgery is necessary.||
|U.S. regulatory status||Mifepristone--approved for early medical termination.|
Misoprostol--approved for ulcer treatment.
|Both drugs are approved.||Worldwide, these drugs have been safely used by millions of women for over 10 years.
In addition to the established MTP regimens, there have been reports of women using misoprostol by itself, and without medical supervision. While women are most likely to self-administer misoprostol in countries where legal termination is unavailable (e.g., Latin America), evidence suggests that women in the U.S. are also using this regimen. [To be clear: Misoprostol is not usually used as the only drug for early pregnancy termination; nor should it be used without medical supervision.]
The reported misoprostol-only regimens involve multiple doses, taken at 24-hour intervals. How well the regimen works depends on the time elapsed from the last menstrual period (LMP) and the number of doses. For example, 800 mcg misoprostol administered vaginally up to 49 days from the LMP, is 69.0% effective after one dose, 86.4% effective after two doses, and 91.7% effective after three doses. For the same dose administered vaginally up to 63 days from the LMP, the effectiveness is 78% after one dose, 91% after two doses, and 92% after three doses.
[Again, please don't use misoprostol on your own; consult with your doctor.]
Williams Obstetrics 21st. ed.
Stewart FH, Wells ES, Flinn SK, et al. Early Medical Abortion: Issues for Practice. UCSF Center for Reproductive Health Research & Policy: San Francisco, California (2001)