About two-thirds of women between the ages of 15 and 49 use some form of birth control. Contraception can decrease the risk of unplanned pregnancies: In 2008, around 51 percent of pregnancies were unplanned. By 2019, teen birth rates (which account for about three-quarters of unintended pregnancies) reached a record low.
Education is one of the most salient factors that ensures people choose the birth control most suited to their needs and increases the likelihood they’ll stick with it. We asked a few different ob-gyns about some of the most popular contraceptives available. How do they work? What are some of the pros and cons? Let’s get into it.
The Pill
Oral contraceptives are used by about 14 percent of women today between the ages of 15 and 49. The so-called “combination pill” is the most typical example; it contains two different hormones, estrogen and progestin.
“These two hormones work together and prevent ovulation, which is the release of an egg from a woman’s ovary,” says Dr. Paul Blumenthal, professor emeritus at Stanford University Medical Center in California. “Since no egg is released, sperm that enters the body doesn’t join with it.”
However, some people might be prescribed progestin-only pills, also called the “mini pill.” This might be a better option if you have a history or family history of blood clots or are lactating.
While the combination pill completely stops ovulation, the mini pill thickens the mucus at the entrance of the uterus, which prevents sperm from passing through.
Hormonal contraceptives, like the pill, are more than 99 percent effective when used correctly. Failure rate increases with misuse, though; one of the downsides to the pill is that it can be difficult to remember to take every day.
Providers instruct patients to take the pill at the same time daily. It’s more critical to do this with the mini pill than the combination pill.
“If there are gaps in the interval between pills or even missed pills, especially around the time of ovulation, the mucus can thin enough for sperm to ascend and fertilization to occur,” Blumenthal says.
Birth control pills can come with pesky side effects, which makes some users seek out different options. These can include headaches, mood changes, nausea, weight gain and other issues. However, despite these drawbacks, the pill remains inexpensive and doesn’t cause any long-term impact on fertility. As an added benefit, it also often reduces acne.
Bar/Implant
Around 1 in 10 people who can become pregnant use long-acting reversible contraceptives. For one popular option, providers can implant a small plastic rod in the upper arm using an applicator attached to a needle. Once inserted, the implant continuously releases a low dose of a progestin hormone called etonogestrel, which doesn’t contain estrogen. This makes it a good option for people who cannot use contraceptive methods with estrogen.
The bar is 99 percent effective at preventing pregnancy and can last for three to five years. If a patient isn’t currently on contraception, the implantation must take place within five days of a new menstrual cycle. For some patients, the bar can help with painful or heavy periods. Side effects can include acne, mood changes, weight gain and other issues.
The Patch
Like the pill, the patch stops ovulation. Unlike the pill, you replace it every seven days: The patch is more or less a small square bandage that releases estrogen and progestin through the skin. It can be applied to clean, dry skin on the belly, buttocks, back, lower abdomen or other spots that aren’t affected by bending or flexing.
The patch is designed to stay put when you’re showering, swimming, sweating or even using a hot tub. Still, Blumenthal suggests checking that it’s in place after contact with water and daily in general.
“This method may be best for women who may struggle to remember a daily pill, like someone who travels often, or someone who just has difficulty swallowing pills,” he says.
Like any adhesive bandage, the patch can be difficult to keep on the skin and can cause irritation. It also has a weight limit; the American College of Obstetricians and Gynecologists says efficacy decreases in patients who weigh more than 198 lbs.
IUDs
Intrauterine contraceptives, also called intrauterine devices (IUDs), consist of a small device that a provider inserts into a person’s uterus to avoid pregnancy. Some can last up to eight years; all have a failure rate of less than 1 percent, some far less. An IUD’s effectiveness is often related to its ease of use; once it’s inserted, there’s no forgetting to use it.
One subset of IUDs uses hormones to stop ovulation and thicken the lining of the cervix, which traps and stops sperm. The other type, which is made of copper and doesn’t contain hormones, “makes it impossible for sperm to reach an egg, because sperm hates copper,” Blumenthal says.
“These are my go-to ‘brainless, reversible’ methods,” says Arizona-based ob-gyn Dr. Monte Swarup, noting that hormonal IUDs can eliminate periods or reduce heavy bleeding.
That said, as you may have heard, IUD insertion is often notoriously uncomfortable. Additionally, there’s a rare but present risk of an IUD perforating the uterus at the time of insertion.
Surgery
The most popular contraceptive method for women, particularly married women, between 15 and 49 isn’t chemical — it’s surgical. Every year in the United States, about 600,000 people with uteruses undertake tubal ligation, or “getting your tubes tied,” with demand for the surgery soaring in light of legal uncertainty about abortion access going forward.
Between 200,000 and 300,000 people with penises opt annually for vasectomies, “minor surgical procedures that tie off and block the tubes that carry sperm in the body,” Blumenthal says. Since a vasectomy ensures that sperm never reaches a male’s semen and can’t fertilize an egg during sexual intercourse, it’s nearly 100 percent effective at preventing pregnancy. About 3 to 6 percent of people who’ve had vasectomies seek to undo them each year, and about 91 percent of patients became fertile again after a reversal.
Esther Bergdahl contributed to this article. Esther Bergdahl is a freelance writer and editor based in Chicago. Her work has appeared in Pacific Standard, Publishers Weekly, CityLab and Smithsonian Magazine. Learn more at estherbergdahl.com.