Without ongoing education, our knowledge about birth control is frozen in time. In The State of Your Birth Control, Lifehacker follows the history of contraception in the U.S. and explains what everyone needs to know about their options, recent medical advancements, and legal access. Follow the complete series here.
The ways we prevent pregnancy have not only changed over the years—in many cases, we learned the wrong “facts” about them in the first place. You may have been lied to in sex ed class, or picked up misconceptions from social media or chatting with friends. You may also just be remembering things that were once true but that don’t apply to the method you’re using today. So let’s set some of these myths straight.
Myth: Condoms have holes that sperm or HIV can pass through
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This is misinformation, even though it’s been confidently taught in some sex-ed classes. Condoms do not have holes that sperm can pass through. Even lambskin condoms—which are not recommended for preventing STIs—have holes too small to let sperm through. Sperm can’t leak out of an intact condom, although it’s possible for a condom to break or for semen to leak out of the open end after an erection has gone soft.
Condoms do not (usually) have holes that viruses can pass through, and they are effective against preventing the transmission of HIV and other viruses. It’s true that viruses, including HIV, are very small. HIV is about 145 nanometers wide, or 0.1 micron. So how big are the pores in a condom? Well, several studies have looked for pores and not been able to find any. Pores don’t naturally occur in latex condoms, although they can occur as manufacturing defects.
One study found pores in some store-bought condoms, but that same study concluded that in a “worst case scenario” of wearing a condom with defects and thrusting for 10 minutes after ejaculating, it might be possible for some virus to work through a defect in the latex—but that based on data from their tests, the expected leakage in the worst case scenario would still be “at least 10,000 times better than not using a condom at all.”
So technically it’s possible for a virus particle to make it through a condom, but in real world studies, condoms turn out to be at least 95% effective at preventing HIV transmission when used correctly and consistently.
Myth: All birth control pills should be taken at the same time every day
This one is true of some types of birth control, but not others. If you’re on a combination pill, you don’t need to worry about it.
Progestin-only pills, known as “mini” pills, do need to be taken at approximately the same time every day. Depending on which pill you take, you may have a window of about three hours (in which case 2 p.m. is just as good as noon) or your window may be more forgiving—some only need to be taken within 12 hours of your usual time. Check the package information for your pill, or ask your doctor or pharmacist. If you miss your window, you can usually take an extra pill to get back on track, but you may need to use a backup method for a few days. Planned Parenthood has a missed pill quiz that will ask you about what kind of pill you take and when you missed it, and will advise you about what to do.
Combination pills, which are the more common type, aren’t as time sensitive. If you usually take a combination pill at noon, and you forget until late that evening, you can take the pill then and still be protected. If it’s been more than 24 hours, though, refer to the package insert or the missed pill quiz to get back on track.
Myth: IUDs are dangerous
Intrauterine devices are a set-it-and-forget it birth control method that is not new, but is becoming more popular. That wasn’t always the case.
In the 1980s and 1990s, almost nobody in the US was getting IUDs inserted. The popularity of the devices plummeted after one particular model, the Dalkon shield, was found to cause pelvic inflammatory disease and other complications. At least 21 women reportedly died as a result, and thousands suffered infertility or other serious effects.
But the Dalkon shield was unique. It was far worse at preventing pregnancy than other IUDs of its day (there were 70 on the market), and its string may have acted as a channel to allow bacteria to enter the uterus. (It’s unclear whether the string is the only reason for the deaths and illnesses; in hindsight, experts say, there may have been other factors to blame. For example, the device’s crab-like shape may have made it harder to place correctly, which would account for the lower effectiveness as well as the higher rates of complications.)
Whatever the reason, people were understandably scared off. But the Dalkon shield was only manufactured from 1970 to 1974, and modern IUDs bear no resemblance to it. Gynecologists consider today’s IUDs to be extremely safe and effective.
Myth: You can only get an IUD if you have already had children
Some doctors have been reluctant to give IUDs to people who have never given birth, but the American College of Obstetricians and Gynecologists points out to their members that IUDs are just as safe and advisable for teens and “nulliparous women” (those who have not given birth) as they are for anyone else.
If you’ve ever had a doctor tell you they can’t give you an IUD because you haven’t had kids, they aren’t keeping up with the medical literature (or even the package inserts on those devices!) and you should find a new doctor.
Myth: Hormonal birth control increases your risk of cancer
Some studies have found that oral contraceptives slightly and temporarily increase the risk of breast and cervical cancer, but these findings are inconsistent—some studies find no link between birth control and breast cancer.
But it’s also important to note that birth control pills seem to reduce the risk of endometrial, ovarian, and colorectal cancer. On balance, it seems likely that hormonal birth control prevents more cancers than it causes.
Myth: It’s unsafe to skip your period
Birth control pills often come in a pack that includes inactive pills. During the week you take these pills, you have your period. But it’s fine to skip those pills, and just start the next pack of pills right away. This means you won’t have your period—and that’s totally fine.
There’s no medical need to trigger your body to have a period. Longer-acting contraceptives like Depo-Provera (a shot given every 12 weeks) and hormonal IUDs (like Mirena, which lasts for eight years) don’t give you a break from the hormones. You may end up having lighter periods or no periods at all while you’re using those methods.
Myth: If you had unprotected sex and didn’t get pregnant, you’re infertile
This is another holdover from bad sex ed. There’s often an emphasis on the idea that you can get pregnant even if you only have sex once (true) that people end up believing that they are likely to cause a pregnancy every single time they have sex. That part is not true.
In a person who ovulates regularly, typically only a few days out of each month are “fertile” days. Most of the time, we don’t know which days those are. (That said, if you’d like to geek out about this, there’s a whole thing called fertility awareness where you attempt to track your fertile days, for the purpose of either getting pregnant or avoiding pregnancy.)
There are also other reasons why a person might not get pregnant. For example, you might not ovulate every month. This is more common with teenagers and with people who have recently given birth, as well as in certain medical conditions like PCOS.
And even if you have sex right around the time of ovulation, it’s still unpredictable as to whether a sperm cell ends up meeting an egg cell. And then, after fertilization, many embryos don’t implant or don’t end up developing into a pregnancy. In fact, it’s so common to have sex and not get pregnant that people who are trying for a baby are not considered to be dealing with infertility until they have been trying for a full year. So that one time you had sex and you or your partner didn’t get pregnant? You may just have gotten lucky.