“There is no way you can be a good mother while achieving what I aspire."

“Let’s face it. It’s a man’s world. The woman always stays home with the child.”

“It’s hard to do this job with two kids.”

These are just a few phrases working mothers reported hearing from their supervisors when discussing promotions or demotions, according to recent court filings. The subtle—and sometimes overt—perception illustrated by these statements—that mothers are less devoted to their jobs than childless workers—has been dubbed “the Maternal Wall” or “the New Glass Ceiling.” This has led to a wave of claims of gender discrimination based on parental responsibilities, which now make up a growing number of lawsuits against American employers.

In the past decade, the number of caregiver-discrimination lawsuits has tripled compared to the previous decade, according to research from the Center for WorkLife Law at the University of California, San Francisco. Between 2006 and 2015, researchers found that more than 3,000 such cases were decided in state and federal courts, even as overall federal job-discrimination claims were declining. This growing number of lawsuits includes claims from mothers, fathers and those who take care of ill or disabled relatives. These aren’t baseless lawsuits either, as more than half have led to compensation for victims—a higher-than-average success rate for job-discrimination claims.

In a major class-action lawsuit filed last summer, seven high-level female employees of the software developer, Qualcomm, sued the company on behalf of more than 3,000 female workers for gender discrimination, including motherhood discrimination. The women claimed that they were repeatedly passed over for advancement in favor of less-qualified male employees. They believe this explains why women make up only 5 percent of senior management positions at the San Diego-based tech firm, and only 5 percent of top engineering positions. “Qualcomm maintains an unwritten policy of disparately rewarding employees who work late into the night over employees who choose to arrive early and leave at the end of a normal work-day. This policy disparately impacts and causes the Company to undervalue caregivers of school-aged children ... These common policies stigmatize employees with caregiving responsibilities and disproportionately penalize women,” they wrote in their complaint.

One of the plaintiffs, a senior-level market analyst and working mother, said that she was passed over for promotions in favor of substantially less-qualified male workers despite her outstanding performance reviews. One top engineer with three school-aged children said she began receiving negative evaluations and fewer promotions compared to less-qualified male peers after she asked to scale back her work schedule to 30 hours per week to take care of her children—even though she says she was just as productive as before. The same month that employees filed the lawsuit, Qualcomm agreed to settle the case for $23.5 million. Of that payout, $19.5 million will be paid to the female employees, and the company agreed to spend another $4 million to ensure equal opportunities for women at Qualcomm. “While we have strong defenses to the claims, we elected to focus on continuing to make meaningful enhancements to our internal programs and processes that drive equity and a diverse and inclusive workforce,” a spokesperson from Qualcomm said in a statement.

Cynthia Calvert, a senior advisor at the WorkLife Center, says that caregiver discrimination is one of the fastest-growing areas of employment law. “Employers haven’t realized that discrimination against motherhood or fatherhood can be gender discrimination,” she says. It’s particularly insidious in supervisors’ biases about gender roles. With women, she says, a common scenario involves overlooking female employees for  challenging assignments because employers assume mothers won’t want to travel or handle the extra workload. “With men, they are punished because they want to work more flexibly to take care of a child, and the employer thinks they’re not acting the way men are supposed to act,” says Calvert, who has analyzed thousands of parental-discrimination cases. While claims filed by fathers are fewer than those filed by working mothers and pregnant women, Calvert says the number of male plaintiffs has increased sharply in the past decade.

Under federal law, it’s not explicitly illegal for employers to discriminate against working parents, though employees have succeeded in showing that it can be deemed unlawful sex discrimination under the Civil Rights Act of 1964, which prohibits job discrimination based on religion, race, sex, and national origin. Several states and the District of Columbia have gone farther than federal laws by making it illegal to punish workers who need accommodations for caregiving responsibilities. Last year, New York City Mayor Bill de Blasio signed such a law, which went beyond protecting pregnant women and parents, to include all people who provide care for relatives, such as grandparents and those who look after their disabled parents.

The problem of caretaker discrimination is costing companies a lot of money. In the past decade, employees were awarded nearly half a billion dollars in verdicts and settlements, according to the WorkLife Center’s report. That is more than double the amount awarded the decade before. And these numbers do not include confidential settlement agreements, which means that the total cost is likely higher. The trend reflects the shifting gender roles in American families and workplaces. In 1960, about 25 percent of household with children had both parents working, by 2012 that had jumped to 60 percent.

Calvert says that companies are starting to pay more attention to potential parental discrimination, and she believes preventative training around the issue will one day become normal. She points out that though it seems commonplace now, it took American businesses many years to understand that sexual harassment in the workplace was illegal gender discrimination. Things started to change when lawsuits began affecting the bottom line, and now employee-training videos and employee handbooks outlining illegal sexual harassment are the norm. If the courts keep siding with working parents, American companies may have to take notice.