BIRTH CONTROL PILLS – PATIENT INFORMATION
Most oral contraceptives, commonly called "the pill,"
contain a combination of estrogen and progestin. The combination pill
reduces the risk of pregnancy by:
- Preventing ovulation
- Keeping the mucus in the cervix thick
and impenetrable to sperm
- Keeping the lining of the uterus
thin
The pill makes menstrual bleeding more regular, with
fewer days of flow and overall lighter flow. Other benefits of the
pill include a reduction in:
- Menstrual cramps or pain
- Risk of ovarian cancer or cancer of the endometrium (uterine
lining)
- Acne
- Iron-deficiency anemia (a low blood count
due to low iron levels)
One potential downside of the pill
is that in order to maximize efficacy, you have to remember to take it
every day, ideally at the same time of day. Some women find this
difficult or inconvenient.
Efficacy — When taken properly,
birth control pills are a highly effective form of contraception;
however, skipping pills or forgetting to restart the pill after the
week of your period will decrease efficacy. Approximately 9 out of
every 100 women who take birth control pills for one year will have an
unintended pregnancy.
Missed pills are a common cause of
pregnancy. In general, if you forget to take an active pill
(containing hormones), you should take it as soon as possible and take
the next one at the usual time it is due. If you miss more than two
pills, use a backup method of birth control (eg, condoms) for seven
days.
Side effects — Possible side effects of the pill
include:
- Nausea, breast tenderness, bloating, and mood
changes – These typically improve within two to three months without
treatment.
- Bleeding between periods – Irregular
bleeding, also called "breakthrough bleeding" or
"spotting," is particularly common during the first few
months of taking the pill. It almost always resolves without any
treatment within two to three months. Forgetting a pill can also cause
breakthrough bleeding.
Taking birth control pills does not
cause weight gain.
If you are taking the pill, tell your
doctor right away if you experience abdominal pain, chest pain, severe
headaches, eye problems, or severe leg pain. These could be symptoms
of several serious conditions including heart attack, blood clot,
stroke, and liver or gallbladder disease.
Potential
complications — When the pill was first introduced in the 1960s, the
doses of both hormones (estrogen and progestin) were quite high.
Because of this, cardiovascular complications occurred, such as high
blood pressure, heart attacks, strokes, and blood clots in the legs
and lungs.
The pills prescribed today have much lower doses
of progestin and estrogen, which has decreased the risk of these
complications. As a result, birth control pills are now considered a
reliable and safe option for most healthy, nonsmoking women. While
there is a very small risk of blood clots, this risk is actually lower
than the risk in pregnant women or those who have recently given
birth.
Experts have studied the possible association
between taking the pill and the risk of breast cancer. While these
studies have had mixed results, there is some evidence that women who
take the pill do have a slightly higher risk of getting breast cancer
later in life than women who do not. However, if there is an increase
in risk, it is very small, especially in younger women. It's
important to balance this against the benefits of the pill, which
include not only pregnancy prevention but a reduction in the risk of
ovarian and endometrial cancer (see above).
Who should not
take the pill? — Because of an increased risk of complications, you
should not take the pill if you:
- Are 35 or older and
smoke cigarettes (as this puts you at high risk for cardiovascular
complications such as blood clots or heart attack)
- Are
pregnant
- Have had blood clots or a stroke in the past
(as this increases your risk of blood clots while taking the pill)
- Have a history of an "estrogen-dependent" tumor
(eg, breast or uterine cancer)
- Have abnormal or
unexplained menstrual bleeding (in which case the cause of the
bleeding should be investigated before starting the pill)
- Have active liver disease (the pill could worsen the liver
disease)
- Have migraine headaches associated with certain
visual or other neurologic symptoms (eg, aura), which increases your
risk of stroke
-Some women may take the pill under certain
circumstances, but need close monitoring. Talk with your doctor if
you:
- Have high blood pressure – You may experience a further
increase in blood pressure and should be monitored more frequently
while on the pill.
- Take certain medication for seizures
(epilepsy) – In this case, the pill may be slightly less effective in
preventing pregnancy because the seizure medicines change the way it
is metabolized.
- Have diabetes mellitus – Women with
diabetes and kidney disease or vascular complications from diabetes
should not use the pill.
- Medication interactions — The
pill may not work as well to prevent pregnancy if you also take
certain other medications.
- Anticonvulsants — Some
anticonvulsants decrease the effectiveness of birth control pills. As
a result, women who take these anticonvulsants are advised to avoid
hormonal birth control methods (with the exception of
depo-medroxyprogesterone acetate [Depo-Provera]).
If you
take any anti-seizure medications, it's important to talk with
your doctor about possible interactions before starting the pill or
another hormonal birth control method.
Antibiotics —
Rifampicin, which is used to treat tuberculosis, can decrease the
efficacy of hormonal birth control. As a result, women who take
rifampicin are advised to avoid most hormonal birth control methods,
with the exception of depo-medroxyprogesterone acetate (Depo-Provera).
Other alternative options include an intrauterine device (IUD),
condoms, or a diaphragm, or sterilization.
Contrary to
popular belief, other (more commonly used) antibiotics do not affect
the efficacy of hormonal birth control methods. Backup contraception
is not needed when you take these antibiotics.
Starting the
pill — Ideally, you should start taking the pill on the first day of
your period. This provides protection from pregnancy beginning
immediately.
As long as you are sure you are not pregnant
(which can be confirmed with a urine pregnancy test), it is also an
option to start the pill as soon as your doctor prescribes it,
regardless of where you are in your menstrual cycle. This is called
the "quick start" method. If you do this, you will need to
use a backup form of birth control (eg, condoms) for the first seven
days after the quick start.
Many women start taking the
pill on the first Sunday after their period starts (because most pill
packs are arranged for a Sunday start). If you do this, you will also
need to use some form of backup contraception (eg, condoms) for the
first seven days after the Sunday start.
When to expect a
period — Traditionally, the pill is taken on a 28-day cycle that
includes 21 days of hormone pills followed by 7 days of placebo pills
("sugar pills") that do not contain hormones. Newer
formulations have a longer duration of hormone pills (eg, 24 days) and
fewer days of placebo pills (eg, 4 days). It is not necessary to take
the placebo pills, as they do not contain any active ingredients, but
many women find it easier to stay on schedule when they continue to
take a daily pill throughout the entire 28-day cycle.
Your
period should arrive during the fourth week of the pill pack (ie, the
week that you are taking placebo pills or no pills). However, some
women have irregular breakthrough bleeding or spotting in the first
few months.
Continuous dosing — Some women prefer to take
hormone-containing birth control pills continuously, without the week
of no pills or placebo pills. This allows you to control whether and
when you have a monthly period. This regimen often works well for
women with painful periods, endometriosis (a condition that causes
abdominal pain), or bothersome premenstrual symptoms, including mood
changes.
Traditional birth control pill packs can be used
in continuous dosing. To do this, you take the first three weeks of a
pill pack, then immediately start a new pack the next day (without
taking a break or taking the placebo pills). This can be continued for
as long as desired.
Over time, using continuous-dosing
regimens results in fewer periods per year (or no periods at all);
however, many women experience breakthrough bleeding when starting a
continuous-dosing regimen. Breakthrough bleeding is inconvenient, but
does not mean that the pills are less effective (assuming you are
taking them at the same time each day and not skipping any active
pills).
Progestin-only pills — Some pills contain only
progestin (sometimes called the "mini pill"); these may be
an option for women who cannot or should not take estrogen. This
includes women who are breastfeeding or who have worsened migraines or
high blood pressure with combination contraceptive pills.
Progestin-only pills are as effective as combination pills when taken
at the same time every day, but have a slightly higher failure rate if
you are more than three hours late in taking it. A backup method of
birth control should be used for seven days if you forget a pill or
are more than three hours late in taking it.
Progestin-only
pills are taken on a 28-day cycle, and all 28 pills contain hormone
(ie, there is no "placebo week"). Breakthrough bleeding or
spotting is common with progestin-only pills.