Píldoras anticonceptivas

Context

Why are birth control pills important? Why should we care?

Close to half of all pregnancies in the U.S. are unintended; birth control pills are an easy method of prevention (which is important for all sorts of reasons). They are safe and effective for most women.

How might you decide if the pill is the right approach?

It’s almost always a matter of patient preference. All hormonal contraception works by suppressing ovulation, so it’s just the method that differs.

Women might prefer the pill because they want to take a medicine orally and don’t want to have a procedure, which they would need with long-acting reversible contraception (LARC), such as an IUD. Or they may prefer the pill because the estrogen it contains has benefits (like skin improvement), which non-estrogen methods don’t have.

But all forms of hormonal contraception—the pill, the patch, the ring, the shot, the progestin IUD, and the implant—are all just as effective. The best-acting non-hormonal form of reversible contraception is the copper IUD (which works just as well as the progestin-containing IUD).

Are there medical conditions or other factors that affect the decision?

Some women have predisposing health concerns that make estrogen use unsafe (e.g., migraine with aura, uncontrolled high blood pressure, cigarette smoking). For those who can’t safely take the traditional birth control pill, there are other great options, including the mini-pill (progestin only), an IUD (none of them have estrogen), or the implant.

How do you choose the right pill for someone?

Although there are many brand names for the pill, the differences among them are very slight: Some have a tiny bit less estrogen (or none altogether), while others have varying types of progestin.

For most people, these differences don’t have any impact. However, for some, a dose adjustment might cause a noticeable change. For instance, if a woman is experiencing breakthrough bleeding with a low-dose pill, one with a higher dose of estrogen could eliminate that unpredictable bleeding.

Benefits

Beyond contraception, what are the benefits of birth control pills?

Clearer skin, lighter periods, decreased symptoms of PMS, and protection against osteoporosis are just a few of the benefits.

Research also shows that taking the pill can reduce a woman’s risk of ovarian cancer by up to 50%. Similarly, there is a 30% reduction in the risk of endometrial cancer, and an estimated 15-20% decreased risk of colon cancer.

Cancer risk reduction seems to take effect within three-to-six months of starting the pill, and increases with duration of use. It can last for many years after discontinuation. In one study, ovarian cancer protection was estimated to last for up to 30 years.

Lastly, almost all women experience lighter bleeding with the pill. With continuous contraception, many achieve absence of a period altogether, which is perfectly safe.

In fact, the “period” that women usually experience during their placebo (pill-free) week is not actually a period. It’s simply the body’s response to a change in hormone levels (also known as a “withdrawal bleed”). While using hormonal birth control, it is completely safe to not have a true period--progestin keeps the lining of the uterus healthy.

Is there any new science around birth control pills?

Yes, the newest pills on the market have very low doses of estrogen, which can be great for people who are particularly sensitive to hormones. Low-dose pills are just as effective for contraception as those containing higher doses of estrogen.

Risks

What are the risks of birth control pills?

The primary risk is for blood clots (which can lead to stroke). For most people taking a pill with both estrogen and progestin, this risk is very low—lower, in fact, than the risk for getting a blood clot during pregnancy.

Among those taking a progestin-only pill, the risk is much lower than for those who smoke cigarettes or have migraine with aura.

Can you talk about birth control and cardiovascular disease?

As mentioned above, there is a known—but low—risk of blood clots with estrogen use. This applies to all users of the estrogen-containing pill, but especially those who have certain contributing factors (i.e., cigarette smoking, high blood pressure, migraine with aura).

In the 1960s, there was thought to be a link between the pill and heart disease—namely, an increased risk of myocardial infarction (heart attack). However, newer versions of the pill have lower doses of estrogen and do not appear to increase the risk of heart disease.

What about breast cancer?

Some studies suggest a connection between the pill and an increased risk of breast cancer. More research is needed on this topic to determine whether there is a clear link.

Most current data reflects that any potentially increased risk is diminished within five-to-ten years after discontinuing the pill. For women with a personal or family history of breast cancer, it’s important to weigh the risks and benefits of different birth control options.

Who should NOT take birth control pills?

Because of the increased risk of blood clots associated with estrogen use, women who have certain medical conditions should not take the traditional, estrogen-containing pill. These conditions include migraine with aura, uncontrolled hypertension, cigarette smoking, liver disease, a past history of blood clots, and recent surgery requiring immobilization.

Other women who should not take the estrogen-containing pill include those who have had a baby within the past three weeks (estrogen can interfere with milk supply) and those who have or have had breast cancer (due to a possible connection between estrogen use and breast cancer).

For women with any contraindication to estrogen, a form of contraception that contains progestin only or no hormone at all is generally considered safe. Among the most effective versions of these options are progestin-only pills, the progestin shot, the progestin implant, the progestin IUD, and the copper IUD.

Apart from the major contraindications, are there people who may not be best suited for the pill?

People who travel frequently through different time zones or those who have unpredictable schedules often find it difficult to take a daily pill at the right time, and this leaves them vulnerable to pregnancy. A LARC method—such as IUDs or implants—may be easier and, therefore, more reliable.

When to Use

Provided you're not trying to get pregnant, what is the right age to stop the pill?

Stopping the pill near menopause makes sense because postmenopausal women no longer need birth control. Because there’s no way to know when a woman on the pill has gone through menopause, it’s generally considered reasonable to try going off the pill in one’s late-40s.

That said, a common misconception is that women in their late 40s and early 50s can’t get pregnant. A woman can get pregnant if she’s still ovulating, and even a very infrequent period indicates that ovulation is happening—though rarely. Therefore, if a woman stops the pill and finds that she is still menstruating, it’s safe to go back on and try discontinuing again in another year or two (under the guidance of a healthcare provider).

Once a woman does go through menopause (defined as twelve full months without a spontaneous period), hormonal contraception is no longer necessary and the risk (e.g. stroke) outweighs the benefit.

For those wishing to continue taking hormones to manage menopause, the doses contained in hormone replacement therapy—often used to ameliorate symptoms such as hot flashes—are much lower than are those contained in the pill.

Is there any evidence about when to start birth control?

The pill is safe to use in adolescence. It’s often started for reasons other than birth control, including improvement in acne and heavy or crampy periods.

What about continuous contraception? Is there a reason people should ever have periods?

Continuous contraception—taking hormones throughout the menstrual cycle (whether by pill, patch, ring, or LARC)—is safe, and there is no need to ever have a period while using hormonal birth control.

In fact, the “period” that a woman experiences during the placebo week of her pill, patch, or ring is not a real period. It’s simply the body’s response to decreased hormone exposure during that phase.

If a premenopausal woman doesn’t get a period regularly while not using hormonal birth control, there’s a risk that the lining of the uterus (the endometrium) will thicken excessively, which can increase the risk of endometrial cancer.

However, the progestin contained in all forms of hormonal contraception prevents the endometrial lining from building up. It keeps the endometrium safe and healthy. Therefore, a period is not necessary while using hormonal birth control.

Does the pill affect fertility?

No, not at all. The pill acts as a temporary method of suppressing ovulation. The hormones in the pill signal to the ovaries that they do not need to release an egg. Once that hormonal stop sign is removed, the ovaries are ready to go back to business as usual.

What do you advise patients who are on the pill and considering getting pregnant?

If someone has a strict timeline and wants to try to get pregnant as quickly as possible, I recommend coming off the pill a few months in advance, and then using condoms until she’s ready to start trying.

For others, I recommend staying on the pill until you’re ready to start trying. Some women get pregnant right away. For others, it may take three-to-six months to go back into a regular ovulatory rhythm, and there’s no way to precisely predict when ovulation will occur for a particular individual.

Related Topics

Can birth control help clear acne?

When does birth control start working?

Which birth control pill is best?

How does the birth control patch work?

Do you ovulate on the birth control pill?

Enlaces útiles

Guía del usuario de la píldora (Proyecto de acceso a la salud reproductiva)

Métodos anticonceptivos (Departamento de Salud de la Mujer del HHS)

Estadísticas de embarazos no deseados (CDC)

Ayuda para seleccionar métodos anticonceptivos (Planned Parenthood)

‍