Dear Dr. Jeff: I've heard a lot of discussion recently
about "Emergency Contraception". Is that the "Morning After
Pill"? Is it available at the Health Center? S.G.
Dear S.G.: A variety of forms of "Emergency Contraception"
("EC") are currently available. Dedicated "Morning-After
Pills" contain some combination of progesterone and estrogen. "Preven"
contains both estrogen (ethinyl estradiol) and progesterone (levonorgestrel),
the hormones found in most oral contraceptive pills. In Preven, they are
formulated in considerably higher doses. Multiple doses of birth control
pills (often "Ovral"), can also be taken in a similar manner
with the same effects. "Plan B" contains only the progestin,
levonorgestrel. It is more effective than Preven and Ovral, and has far
fewer side effects. Plan B is the formulation we prescribe at the Health
exact mechanism of action of these hormonal preparations is complex. Human
and animal studies have shown effects at several stages of the reproductive
cycle: ovulation, fertilization, egg transport and hormonal support, and
implantation. If the timing is right, like regular birth control pills,
EC will suppress ovulation and cause changes in cervical mucus that make
it impenetrable to sperm. It will also impede transport of a fertilized
egg through the fallopian tubes to the uterus, as well as implantation
of the egg in the endometrial lining of the uterus. None of these medications
will harm an implanted embryo.
All forms of emergency contraception should be taken as
soon as possible after unprotected intercourse. A second dose needs to
be taken 12 hours after the initial dose.
If 100 women have completely unprotected intercourse during
the second or third week of their cycles, studies have shown that eight
will likely conceive. Preven and Ovral are about 75 percent effective,
and will reduce this number to two women. Plan B is 89 percent effective,
and so reduces this number to one.
The sooner EC is taken, the more effective it is. While
this was always intuitively clear, recent studies have demonstrated that
every 12-hour delay in starting the medication may decrease its effectiveness
by as much as 50 percent.
Three million unintended pregnancies occur each year in this country. Half of all American women will have at least one unintended pregnancy. The majority of these women use a regular method of contraception, none of which, unfortunately, is 100 percent effective. Accidents happen: condoms break, diaphragms slip, birth control pills are sometimes forgotten.
Sometimes sex is unplanned - or unwanted. Very sadly, each
year, thousands of American women are the victims of rape. Emergency contraception
can at least help eliminate one associated trauma - the prospect of an
At the Health Center, we consider emergency contraception
a safe, effective, back-up birth control method. By delaying or inhibiting
ovulation or fertilization, or preventing transport or implantation of
a fertilized egg in the uterus, EC prevents pregnancy. Emergency contraception
does not interrupt a pregnancy. It will not work if a woman is already
pregnant, and it will not harm a developing fetus.
Emergency contraceptive pills are available in the U.S.
only by prescription. There has been much discussion about how to improve
women's ease, speed and cost of access to EC. In three states now (California,
Washington and Hawaii), women are able to obtain emergency contraception
directly from pharmacists without having to visit a clinic or health care
Plan B has been available at the Health Center for some
time. This year, we have been able to add it to our formulary, and dispense
it to students free of charge. We would like all women to have some Plan
B on hand, in their medicine cabinets, immediately available, "just
in case". The sooner after unprotected intercourse Plan B is started,
the more effective it is. Please come in to the Health Center to pick
some up, and to learn more about how to use it safely and effectively.
Jeff Benson, M.D.