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.