One story that Sen. Elizabeth Warren (D-Mass.), a contender for the Democratic presidential nomination, tells on the campaign trail is how she was ushered out of a teaching job in 1971 because she became pregnant. It was a hard-knock lesson in how American employers mistreat their workers, and the discrimination that working women in particular face — but also an ironic change in life circumstances that ultimately put Warren on a course for politics and a run for the presidency.

The story made headlines this week after some conservative media outlets tried to debunk Warren's story. But not only does Warren's narrative hold up, it's not even a relic of an unfortunate past. Pregnancy discrimination is still a widespread problem in American employment today.

Ever since the passage of the Civil Rights Act of 1964, courts have generally concluded that firing or discriminating against a woman because she's pregnant is discrimination based on sex, and thus prohibited. How often discrimination was actually prevented is another matter: During the 1960s, around half of all women who were in the workforce when they first became pregnant left their job by the time their pregnancy reached six months. Then in 1974, the Supreme Court actually took the opposite tack, ruling that pregnancy discrimination did not fall afoul of the Civil Rights Act. That set off a campaign that eventually passed the Pregnancy Discrimination Act (PDA) in 1978, which explicitly forbade "discrimination on the basis of pregnancy," and obligated employers to treat pregnant women the same "as other persons not so affected but similar in their ability or inability to work."

Warren's story happened in the early 1970s, before the PDA. She had just gotten her teaching gig in the Riverdale school system in New Jersey. In April of 1971, the Riverdale Board of Education voted unanimously to extend Warren's contract, but by June of 1971, the Board had accepted her resignation. Warren's explanation is straightforward: In April, no one knew about her pregnancy. "By the end of the first year I was visibly pregnant, and the principal did what principals did in those days: wished me luck, showed me the door, and hired someone else for the job," Warren said earlier this year.

Right-wing reporters have focused on the discrepancy between Warren's account and the Board of Education's records, as well as the fact that Warren left the firing part out of the story back in 2007. On the latter point, Warren told CBS that, as she's gained public stature, she's become more willing to open up about discrimination she's faced in her own past — a perfectly understandable impulse. On the former point, journalist Dana Goldstein, who's written a book on the history of the teaching profession in America, explained that, "It was extremely common to push pregnant teachers out of their jobs, right through the 1970s. These rules were often unspoken and enforced without a paper trail. Economists call it a 'pregnancy bar.'"

That's also what a retired Riverdale teacher, Trudy Randall, told CBS: "The rule was at five months you had to leave when you were pregnant. Now, if you didn't tell anybody you were pregnant, and they didn't know, you could fudge it and try to stay on a little bit longer," Randall continued. "But they kind of wanted you out if you were pregnant."

These days, only about 12 percent of women who are employed during their first pregnancy leave the workforce by the time they're six months along. That's a big improvement, but the problem has certainly not been eradicated. Even the media outlets that have gone after Warren acknowledge this, admitting that pregnancy discrimination is a big problem while accusing Warren herself of lying.

From 1997 to 2011, federal pregnancy discrimination charges filed with the Equal Opportunity Employment Commission (EEOC) or with state and local offices actually went up, from under 4,000 a year to almost 6,000. Almost 31,000 total charges were filed from 2010 to 2015. That increase could well be due to more awareness and action on women's part than a jump in discrimination — data specific to just the EEOC is relatively flat from 2012 to 2017 — but research also suggests that lots of instances of discrimination never lead to formal charges, because women fear retaliation. The maternity care initiative Childbirth Connection estimated that around 250,000 instances of pregnancy discrimination happen each year. The injustices fall disproportionately on low-income female workers in sectors like fast food, retail, and health care, and on women of color.

A recent investigation by The New York Times, which combed through troves of court documents, concluded that "many of the country's largest and most prestigious companies still systematically sideline pregnant women. They pass them over for promotions and raises. They fire them when they complain." Offenders include Walmart, Whole Foods, AT&T, 21st Century Fox and even Planned Parenthood. In low-wage and physically demanding work — policing, shipping, loading, warehouses — the discrimination isn't even subtle, and something as simple as a request for a rest break can result in firing. "A lot of employers are open about their biases," Gillian Thomas, a lawyer with the American Civil Liberties Union, told the Times. "They'll say, 'I can't afford to have you home, it's our busiest time of year.'"

Among upper-class workers, pregnant women are often subtly steered into lower-tier career tracks. (Research also indicates that pregnancy is the inflection point where the pay gap between men and women really opens up.) Not even successful athletes with major corporate sponsors are immune: "Getting pregnant is the kiss of death for a female athlete," said Phoebe Wright, a runner who was under contract with Nike from 2010 to 2016. "There's no way I'd tell Nike if I were pregnant."

The most brutal aspect of the Times’ investigation was the miscarriages: women who lost their children after they asked their bosses for breaks, lighter workloads, or other assistance, and were refused.

Part of the problem here is that American workers are just disempowered across the board, with few in unions and most having seen at most a few years of tight labor markets in their entire lives. Filing a pregnancy discrimination charge requires support, energy, fortitude, and faith in the system — all things that plenty of male and female workers don't have. America is also relatively unusual among western nations in that its jurisprudence operates on the assumption that employers can fire workers for whatever reasons they want, with only certain exceptions spelled out by anti-discrimination laws. Essentially, the burden is on the worker to prove the firing was unjust, rather than on the employer to prove the firing was just. Courts also tend to read the PDA pretty narrowly; the wording of the law means that businesses can treat pregnant women terribly as long as they treat everyone else terribly too.

At a very basic level, capitalism is just intrinsically hostile to pregnancy: The point is to get as much productivity as you can out of any given worker. But even a normal pregnancy without complications is a physically grueling process, and a woman in the final months in particular will need to take it slow and easy. Continuing to pay and treat her the same, even as her workload declines, is a cost the business has to eat. It will inevitably be in an employer's interest to throw pregnant employees under the bus.

Beyond that, bosses and owners are merely human, and as subject to biases as anyone. The material logic of capitalism feeds into and intertwines with cultural prejudices against pregnant women — and against low-income and non-white women in particular. Thus pregnancy discrimination is a problem extending across the private for-profit sector, the non-profit sector, and the public sector.

In the meantime, 23 states and Washington, D.C. have passed laws building upon the language of the PDA, prohibiting firings and obligating employers to provide pregnant workers accommodations. The Pregnant Workers Fairness Act would do the same at the national level, and has been introduced in Congress every year since 2012. Thus far it has yet to pass.

Want more essential commentary and analysis like this delivered straight to your inbox? Sign up for The Week's "Today's best articles" newsletter here.