In 1978, Congress passed a key piece of legislation called the Pregnancy Discrimination Act, which granted pregnant women equal rights to everyone else in the workplace. Prior to the law, pregnant women would be fired just for trying to start a family. However, the legacy of the law is actually problematic: because it does not require employers to make accommodations for pregnant employees, it can still create an unfair workplace.
For example, say a pregnant woman's job requires her to kneel down to take inventory. This would be a very uncomfortable position for the woman, so she tells her employer that she cannot perform the task because she is pregnant. Well, since she cannot be treated differently, the employer does not have to grant her an easy workload. It is a ridiculous loophole of the rule that can make the workplace very difficult for a pregnant employee.
There are other problems that can arise. An employer may be unwilling to allow a pregnant woman time off so that she can go to doctor's appointments; the pregnant employee may not receive elongated break time to rest, which can be important for both the mother and unborn child; and, ultimately, a pregnant woman can be forced to quit a job she loves because she is, more or less, forced out by a lack of accommodations.
Efforts have been made to bolster the Pregnancy Discrimination Act, but they have not passed through a gridlocked Congress.
So what can working pregnant women do in the meantime? Simply being aware that pregnancy discrimination is an issue is the first step. It truly is easy to overlook the treatment you receive at work, simply under the assumption that modern times would never allow pregnant women to be discriminated against. And yet, it can happen. Take note of what accommodations (or unfair treatment) you receive, as you could have a legitimate civil case to make.
Source: Philadelphia Inquirer, "Pregnancy discrimination: a real-world challenge," Bette Begleiter and JoAnne Fischer, Jan. 8, 2012