Tiffany Beroid, a former Wal-Mart worker forced to take two months of unpaid leave while pregnant, plays with her toddler. (By Lydia DePillis/ The Washington Post)

Last March, after months of very public pressure from shareholders and a class-action complaint by advocates for women and workers’ rights, Wal-Mart quietly changed its policy to begin to provide reasonable accommodations to pregnant workers so they could stay on the job rather than be forced into taking unpaid leave.

On Wednesday, those same advocates filed another pregnancy discrimination charge against the retail giant with the Equal Employment Opportunity Commission, saying that the new policy is ambiguous and isn’t being uniformly enforced.

The case centers on Candis Riggins, 25, who was a maintenance worker at a Wal-Mart in Laurel, Md. In March, just as Wal-Mart announced its policy change, a pregnant Riggins became sickened by the toxic cleaning chemicals she was using on the job. She gave her employer a doctor’s note and asked to be temporarily transferred to another position, such as cashier, for the duration of her pregnancy. Her managers instead told her to take a career preference test, twice, she said, and then never reassigned her.

“I didn’t hear back from anyone,” she said. “Even though I wasn’t able to stomach anything.”

The fumes made her so sick she fainted at a bus stop and wound up in the emergency room twice, Riggins said. She said she tried to “push through” but began to miss work, though she continued to call in. In May, she was fired. Riggins had been the family breadwinner because her husband was out of work. After she lost her job, Riggins, her husband and their two children, ages 2 and 4, were evicted and homeless, sleeping on friends’ couches and then moving into her mother’s house in Washington.

“If Wal-Mart is truly serious about treating pregnant workers fairly and equally in the workplace, the company would step up and clarify its policy as well as ensure pregnant workers know their rights and managers are properly trained,” Dina Bakst, one of the leaders of the advocacy group, A Better Balance, said in a statement.

Wal-Mart’s director of national media relations, Randy Hargrove, said he hadn’t seen the charge, filed Wednesday morning, so he couldn’t comment on the specifics of the case. “But we take this seriously, and we will look into the individual charges once we get them,” he said. “We take our policy seriously. We’re proud of our new policy. It is best in class and goes well beyond federal and most state laws.”

And there’s the rub: Hargrove is right.

The current law, the 1978 Pregnancy Discrimination Act, requires employers to treat pregnant workers just as it would workers who are similar in their ability or inability to work. What does that mean, exactly? Well, in the words of one federal judge, it means employers can treat pregnant workers the way they treat either their most valued or least valued employees, and still be operating within the letter of the law.

Even Wal-Mart’s old policy, which precipitated the first discrimination class action earlier this year, was perfectly legal, Hargrove said. Under that policy, Wal-Mart fired or forced pregnant workers to take unpaid leave for having water bottles, under doctor’s orders, to stay hydrated, or for requesting transfers to light duty or a break from lifting heavy objects.

That’s because Wal-Mart divided workers into two categories: those with disabilities and those with medical conditions. Only those with disabilities were provided a broad array of reasonable accommodations to comply with the Americans with Disabilities Act. Pregnant workers were treated like workers with medical conditions and given a smaller set of accommodations.

The revised policy now is supposed to require managers to give workers with “a temporary disability caused by pregnancy” the same reasonable job accommodations as workers covered under the Americans with Disabilities Act.

But Riggins maintains that didn’t happen to her.

“I was told they were supposed to have a new policy to accommodate pregnant women, which I didn’t experience at all,” Riggins said. “I liked my job. I would happily go back to being a maintenance worker after my pregnancy was over. I just didn’t want to be sick anymore.”

Confusion over the Pregnancy Discrimination Act is also at the heart of a case recently argued before the Supreme Court, Young v. UPS. Because the UPS policy at the time granted light duty and reasonable accommodations only to workers injured on the job, Peggy Young was denied a request, on doctor’s orders, not to lift heavy packages during her pregnancy. She, like other pregnant workers, was treated like other employees injured off the job, say while mowing the lawn or falling off a ladder.

She sued, and lost twice, before the Supreme Court decided to hear the case.

On the day oral arguments were heard in early December, Tiffany Beroid, 30, of Laurel, Md., was outside protesting. Beroid worked as a customer service manager at a Wal-Mart in Laurel. In 2012, when Beroid was seven months pregnant, her doctor recommended that she work light duty. Her managers, she said, told her to take unpaid leave instead.

Her husband, a security guard, worked double shifts to pay the rent. She could no longer pay tuition for nursing school. “We really struggled,” she said. “That took a great toll on me.” Beroid went back to work when her baby was 3 months old.

While on unpaid leave, Beroid connected on Facebook with other women who had faced similar experiences at Wal-Mart. They formed a group called “Respect the Bump” as part of a union-supported OUR Walmart organization.

Beroid told her story in The Washington Post in April. In May, she said, she was fired.

Though she’s organizing rallies around the country, “My hope is to get my job back,” she said. “I love my job. I miss my co-workers.”