EMERGENCY
CONTRACEPTION (THE "MORNING AFTER" PILL)
History:
Originally
developed in the 1960s as treatment for rape victims, this
method has been improved upon over time and continues to
have active research. Though it has no effect on preventing
STDs / STIs, it is a second chance to avoid an unintended
pregnancy. (The chance of getting pregnant after intercourse
is calculated to be between 2% and 30%.) Emergency contraception
methods can use by women to prevent pregnancy after
intercourse in the case of unused contraception (e.g., sexual
assault, forgot to use contraception) or contraception failure
(e.g., condom breakage, IUD expulsion, etc). Emergency contraception
methods are not as effective as the contraceptive methods
listed previously; the true effectiveness is unknown but
is estimated to be above 80% if used within 72 hours from
intercourse. Because of side effects (nausea, vomiting,
heavy periods, breast tenderness) and lower effectiveness,
emergency contraception should not be used as the primary
means of contraception.
How it works:
Emergency contraception pills are thought to work through
a number of effects mostly by preventing fertilization through
disrupting ovulation or interfering with the movement of
sperm towards the egg. Depending on what sort of emergency
contraception is used, other possible mechanisms include
interfering with the corpus luteum or preventing implantation
(i.e., they do not seem to cause abortions, rather they
prevent fertilization in the first place).
How
to Get it:
Most current birth control pills can be used for emergency
contraception though only the Preven emergency contraception
pill has been approved in the US for use. Call or visit
your doctor, health care clinic, or emergency room to learn
how to take the medicine or get it prescribed. Click here
for a list of local clinics, or call 1-888-NOT-2-LATE
for information about method options and provider referral.
Emergency
Contraceptive Pills (most commonly used): This is a regimen
of combined estrogen-progesterone oral contraceptive pills
taken within 72 hours of unprotected intercourse. It may
cause significant nausea and vomiting.
Progestin-only
minipills can also be used; they work through a similar
mechanism as OCPs and may be more effective than the estrogen
+ progesterone combinations
Copper
IUD insertion is a less common method, but works within
5 days of intercourse and may be 98% effective. Copper ions
act to prevent fertilization.
RU-486
(The Abortion Pill):
RU-486
(mifepristone) is an anti-progestin which prevents ovulation
and slows maturation of the uterine lining. A single dose
of mifepristone has been shown in studies to be effective
in preventing pregnancy when given within 72 hours after unprotected
intercourse with low incidence of side effects. By suppressing
ovulation, it acts to prevent fertilization (RU-486 was licensed
for this use in the US on September 28, 2000).
RU-486
can be used only within 49 days of the beginning of the
woman's last menstrual period. The woman takes three mifepristone
pills. Two days later, she returns to the doctor to swallow
a second drug, misoprostol, that causes uterine contractions
to expel the embryo. The woman then will return for a follow-up
visit within two weeks to be sure the abortion is complete.
The
FDA will allow mifepristone to be distributed only to doctors
trained to accurately diagnose the duration of pregnancy
and to detect ectopic, or tubal, pregnancies, because those
women cannot receive mifepristone. Also, the FDA restricted
mifepristone's use to doctors who can operate in case a
surgical abortion is needed to finish the job or in cases
of severe bleeding - or to doctors who have made advance
arrangements for a surgeon to provide such care to their
patients.
Studies
show mifepristone is 92 percent to 95 percent effective
in causing early abortion, by blocking action of a hormone
essential for maintaining pregnancy. Without that hormone,
progesterone, the uterine lining thins so an embryo cannot
remain implanted and grow. The pill-induced abortion can
be painful, causing bleeding and nausea. Heavy bleeding
is a potentially serious side effect but one the FDA determined
is rare. In safety testing of the first 2,100 American women
who took mifepristone, four bled enough to need a transfusion.
Listed
below are the most common formulations and emergency contraception
medications available.
Consult your own physician before using any of these medications
for this purpose.
Common
Emergency Contraception Medications
| Brand
Name |
Formulation |
Dosage |
Efficacy
(estimate)
|
| Preven
Emergency Contraception Kit |
Levonorgestrel
0.25, ethinyl estradiol 50 mcg |
2
tablets initially (within 72 hours of intercourse),
repeat (2 more tablets) in 12 hours |
75
- 85% of pregnancies prevented |
| Ovral |
Norgestrel
0.30 mg, ethinyl estradiol 50 mcg (white tablets) |
2
tablets initially (within 72 hours of intercourse),
repeat (2 more tablets) in 12 hours |
75
- 85% of pregnancies prevented |
| Lo/Ovral |
Norgestrel
0.30 mg, ethinyl estradiol 30 mcg (white tablets) |
2
tablets initially (within 72 hours of intercourse),
repeat (2 more tablets) in 12 hours |
75
- 85% of pregnancies prevented |
|
Levlen, Nordette
|
Levonorgestrel
0.15, ethinyl estradiol 30 mcg (light-orange tablets)
|
4
tablets within 72 hours of intercourse, repeat (4 more
tablets) in 12 hours |
75
- 85% of pregnancies prevented |
|
Levora
|
Levonorgestrel
0.15, ethinyl estradiol 30 mcg (white tablets) |
4
tablets within 72 hours of intercourse, repeat (4 more
tablets) in 12 hours |
75
- 85% of pregnancies prevented |
|
Tri-Levlen, Triphasil
|
Levonorgestrel
0.125, ethinyl estradiol 30 mcg (yellow tablets) |
4
tablets within 72 hours of intercourse, repeat (4 more
tablets) in 12 hours |
75
- 85% of pregnancies prevented |
|
Trivora
|
Levonorgestrel
0.125, ethinyl estradiol 30 mcg (pink tablets) |
4
tablets within 72 hours of intercourse, repeat (4 more
tablets) in 12 hours |
75
- 85% of pregnancies prevented |
|
Alesse
|
Levonorgestrel
0.1, ethinyl estradiol 20 mcg (pink tablets) |
5
tablets within 72 hours of intercourse, repeat (5 more
tablets) in 12 hours |
75
- 85% of pregnancies prevented |
|
Ovrette (progestin-only minipill)
|
Norgestrel
0.075 (yellow tablets) |
Twenty
(20) tablets within 72 hours of intercourse, repeat
(20 more tablets) in 12 hours |
90%
of pregnancies prevented |
|
Mifepristone
|
RU-486,
200 mg |
3
tablets (600 mg dose) one time, followed 2 days later
with misoprostol |
92
- 95% of pregnancies aborted |
