Has modern birth control made abortion a thing of the past? That’s what lawyers for the state of Mississippi want the U.S. Supreme Court to think. In a brief in the the pending case that could overturn abortion rights nationwide, Mississippi’s lawyers wrote, “[E]ven if abortion may once have been thought critical as an alternative to contraception, changed circumstances undermine that view.” Access to birth control has improved, they noted, and some methods’ failure rates are “now approaching zero.” According to Mississippi’s lawyers, effective birth control means people don’t need abortions anymore.

But Sarah, a professional living in the suburbs of Washington, D.C., did.¹ She had always wanted four children, but four was it. So after her fourth child was born, she and her husband researched birth-control options and landed on the one that seemed foolproof: a vasectomy. “We’re very thorough people, very by the book,” she said. “We wanted to make very, very sure we didn’t have an accident.”

Then, on Mother’s Day, Sarah found herself in her bathroom looking at two lines on a pregnancy test. She knew almost immediately that she was going to have an abortion.

Statistically, Sarah’s experience was very unlikely. There’s a reason why vasectomies are touted as one of the most reliable forms of birth control: They have a failure rate of less than 1 percent,² as opposed to something like condoms, which has a failure rate closer to 13 percent. But because a 1 percent chance isn’t zero, some vasectomies fail every year, just like every other form of birth control. As a result, thousands of Americans who took steps to avoid getting pregnant will seek an abortion anyway. A report from the Guttmacher Institute found that about half of abortion patients used contraception in the month they became pregnant. Framing abortion as a procedure that can be avoided through personal responsibility doesn’t prevent abortions from happening, experts told us. Instead, it just places more blame on women.

Americans need better access to contraception. In countries where birth control is cheap or free and more easily available to more people, there are much lower rates of unintended pregnancy, said Dr. Emily Godfrey, a professor of family medicine, obstetrics and gynecology at the University of Washington. The unintended pregnancy rate in the United States is about 21 percent higher than in the average Western country,³ where national insurance or other universal health care programs are common. Likewise, a large drop in unintended pregnancy rates in the U.S. between 2008 and 2011 was correlated to an increase in the use of long-term, reversible methods of birth control, such as IUDs or implants, which have low failure rates. And that large drop in unintended pregnancy rates has led to fewer abortions.

But that’s not the same as saying that using birth control eliminates the need for abortion, Godfrey said. Yes, Americans can choose from 16 forms of birth control, two types of emergency contraception or “morning-after pills,” and three methods of sterilization. But there are many reasons why she says access to abortion remains necessary.

The simplest and most inescapable reason is that birth control can — and does — fail. That’s true even of the most reliable methods of preventing pregnancy, such as IUDs, implants and sterilization. 

Many abortions happen even after using birth control

Percent and estimated number of nonhospital abortion patients in 2014 who reported using different types of birth control in the month they got pregnant

Contraceptive Method	Number (Estimated)	Percent (Weighted)
Used any birth control method	471,300	50.9%
Condom	224,400	24.2
Short-acting hormonal methods	131,300	14.2
Pill	116,400	12.6
Ring	12,700	1.4
Patch	2,200	0.2
Withdrawal	79,400	8.6
Injectables	14,900	1.6
Long-acting reversible methods	9,500	1.0
IUD	7,700	0.8
Implant	1,800	0.2
Sterilization	1,600	0.2
Other	10,100	1.1
Didn’t use birth control	454,900	49.1

According to the Guttmacher Institute study cited in the chart above, about 51 percent of abortion patients in 2014 reported using some type of birth control in the month they got pregnant. The shares of patients in that study who reported using a long-lasting, high-efficacy birth-control method were low — far more respondents said they had used a condom in the month they got pregnant, which doesn’t necessarily mean, of course, that they were using one at the time they got pregnant. But small percentages still represent thousands of individuals. Just 0.8 percent of respondents said they’d been using an IUD in the month they got pregnant, but that 0.8 percent translated to an estimated 7,700 abortion patients that year. Even the 0.2 percent who said they’d used either sterilization or implants represented an estimated 1,600 and 1,800 people, respectively, who ended up needing access to abortion. 

But the political rhetoric of abortion doesn’t reckon with that fact, said Dr. Christine Dehlendorf, a professor of family community medicine at the University of California, San Francisco. “The mantra of ‘safe, legal and rare’ is stigmatizing,” she said. “It’s saying [abortion is] a bad outcome you should be able to avoid, as opposed to a health care service you should be able to access.”

And as a result, people are getting the message that abortion is a purely preventable problem — something a person can avoid if they are responsible enough. Sarah’s story comes from a collection of experiences with abortion that readers shared with FiveThirtyEight. Our database contains hundreds of entries, and a common, recurring theme is that people reported getting pregnant while using birth control — and then felt like they were the ones who had failed. Contributors said they had done everything right, yet they still felt responsible. 

User error does contribute to unintended pregnancy, Godfrey said. That’s especially relevant when you’re talking about methods like the birth-control pill, which has to be taken correctly every day, or physical methods like condoms, which rely on proper usage in the moment. But user error can’t be dismissed as sexual irresponsibility either, she added. It’s just normal human behavior. “There’s research showing, on average, people miss a pill or two each month. That’s not just birth control, it’s all long-term pills … depression, diabetes, everyone,” she said. “Nobody uses any medication perfectly for 25 years. It’s not possible.” 

Over and over, contributors described struggling with the feeling that abortion should be something they needed only if they were victimized, young and uninformed, too poor to get birth control, or just too irresponsible to take it properly. The stigma wrapped up in that stereotype made Sarah feel uneasy about her decision, even though she knew it was the right choice for her. “Society tells you to feel bad, so therefore I felt bad,” she said. “But, ultimately, I realized that if you can’t control when you have an abortion, then you can’t control when you’re going to have children,” she added. “Because I did literally everything I could not to get pregnant.” 

And any attempt to frame abortion as preventable by birth control has to take into account the many reasons why people might not be able to get contraception — and even reasons why some might not want it. Not all sex is consensual, after all. And even for people who can plan ahead, birth control can be expensive — an IUD can run upward of $2,000 by the time you include both the device and doctor’s fees, Godfrey said. Then there’s the fact that the forms of birth control least likely to fail are also the ones patients have the least control over. Some doctors have refused to give patients IUDs they requested and, in other cases, refused to take out IUDs patients no longer wanted. “Black and Latino women are more likely to be counseled to use IUDs and encouraged to limit family size, and more likely to be encouraged to use a [birth-control] method they don’t want,” Dehlendorf said. 

The reality is, birth control might reduce the need for abortions — but it can’t make abortions go away. That’s because the need for abortion goes beyond the capabilities of birth control, Godfrey said. People can be trying to get pregnant and still end up in situations where they want an abortion. There will always be people who couldn’t get reliable birth control. There will always be people who can’t or don’t want to use specific kinds of birth control. And there will always be people whose birth control simply didn’t work.

CORRECTION (May 19, 2022, 10:04 a.m.): An earlier version of this article misstated the failure rate of condoms. It is about 13 percent, not 24 percent — which is the percentage of nonhospital abortion patients in 2014 who reported using a condom in the month they got pregnant.