Two weeks after I returned from maternity leave to my job in Boston as a television-news producer, I found myself facing a demotion. My bosses were kind, even apologetic. The move did not affect my pay and did not reduce my hours. Simply put: The man they had placed in my position during my leave was a better fit than I had been. Not being one to deal well with demotions, I left almost immediately, and eventually found a job in management.

I didn’t fault my employer. I had worked at the company during the most stressful time of my life: twins on the way, an unemployed husband who had been laid off in the economic crisis of 2008, and a newly-bought home suddenly worth nothing. With everything going on, my work had suffered. I accepted that and decided to move on.

But, looking back, I wonder whether my work was judged fairly. According to sociologist Shelley Correll, mothers are more heavily scrutinized than both women without children and men with or without children. Her research shows that motherhood results in biased evaluations of both competence and commitment to a job, that women with children can do the exact same quality work as those without children, and it will be perceived as less well done.

One woman I talked to saw her job go to a childless woman as soon as she left on maternity leave. She was working in television in Connecticut, but when she returned from having a baby, she remembers feeling that the environment had turned so hostile toward her that she took a job at another station at a significant pay cut just to get away from it.

Studies from 2004 and 2010 have shown that mothers start at a lower pay than their coworkers, make less money over time, and they receive raises and promotions less often than their colleagues—that is, when they’re kept around.

Another woman I interviewed, who had been a therapist in Maryland, said everything seemed fine when she took her maternity leave. Two weeks before her scheduled return to work, she received a phone call telling her that her services would no longer be needed.

“There’s a common misperception out there that women try to use their pregnant condition to bilk extra money from their employers, when in reality, it’s the opposite,” said Diane King, an employment attorney in Colorado. “There are many more women discriminated against in the workplace due to pregnancy, family, and gender than will ever come forward to file a claim.”

These testimonials might be similar to stories you've heard before. Though anonymous, they present a picture of women being pushed aside when they have families. In the world of workplace discrimination, particularly for pregnancy, workers fear retribution from an employer or ex-employer so much that many women—including most of the ones I talked to for this story—are afraid to come forward about it.

“Bad references can kill your career, especially if you are specialized,” King explained. “In some businesses, a simple wink and nod can ruin your chances of getting the next job.”

While few women file lawsuits, there are more discrimination claims submitted now than there used to be. In 2006, the Equal Employment Opportunity Commission (EEOC) received nearly 5,000 complaints of pregnancy-based discrimination—a 30 percent increase from the previous decade. In 2010, there were more than 6,000 complaints filed.

The Pregnancy Discrimination Act has been in place since 1978, branching out from Title VII, which states employers cannot discriminate due to gender. In 1986, those laws were upheld in Meritor Savings Bank vs. Vinson, which found that the civil rights law applied to pregnancy-based discrimination.

Under the law, companies of 15 or more employees are required to treat pregnancy equal to all other short-term disabilities in terms of medical coverage and leave. Pregnant employees must be allowed to work, as long as they can perform their jobs. Employers must hold the employee’s position for her for as long as they would for any other employee on any type of disability leave. This was emphasized in 1993 under FMLA, which allows employees up to 12 weeks of unpaid leave for childbirth, family illness, or emergencies—provided the business has more than 50 employees, and the worker has been there full-time for more than a year, or racked up at least 1,250 hours.

However, a recent ruling allowed for employers to let employees go while on maternity leave if the business undergoes a structural shift and eliminates the position during downsizing. And if an employer is able to prove that letting the pregnant employee go had to do with those reasons, it is likely the woman is out of luck.

A big challenge for women who want to take their claims to court is that discrimination can be very hard to prove, Colorado attorney Brian Stutheit says. In many states, videotaping inappropriate workplace behavior for evidence goes against privacy laws. And unless there's a paper trail clearly indicating harassment or discrimination, the evidence is considered circumstantial. In Stutheit's experience, eyewitnesses are hard to come by because they also work for the company and don’t want to jeopardize their own employment.

“The law clearly states the employer can’t retaliate against a woman speaking up for her rights, but many employers do it anyway. They just find another reason down the road,” Stutheit said. “As a lawyer, you can’t glibly tell a client [to] go ahead and air their complaint, if it could cost them their job. And that’s the real world.”

Stutheit calls it the "halo effect”: After a complaint, the employee who filed is treated like an angel for six months or so, then fired for something unrelated. “Employers consider them troublemakers,” he said.

“These are hard cases,” employment-attorney King said of her work. “The law is hard and the judges can be hard.”

King advises that women who feel they have been discriminated against on the grounds of pregnancy or childbirth keep a detailed log of all events and comments, including the date and who was present. She also recommends creating a paper trail by putting all correspondence in email form. Most importantly, they should file a claim with the EEOC. While current employers will be notified of such complaints, they are kept from future employers. Filing an EEOC complaint is a requirement before filing for a lawsuit. The fact that there are few pregnancy-discrimination suits could mean that many people may be satisfied with the way EEOC handles these cases.

“People have to bring claims or this is only going to continue and get worse,” King said. “If we don’t stand up about it, discrimination will be allowed to run rampant in our businesses.”