Oh, if I had a nickel for every time I got this question from an employer, "Hey Eric. We have this pregnant employee and she is very close to term. We're concerned that if she continues working all the way up to childbirth, she may harm herself or the fetus. Can we require her to stay home?"
Eek! Check out this recent press release from the EEOC in which the agency announced that it is suing an employer, which allegedly required a pregnant employee to take unpaid leave until she was cleared by a doctor indicating that she could work despite her pregnancy. The EEOC further alleges, when the employee failed to provide a release, and after she and her mother disputed the legality of the requirement, the employee was fired in retaliation.
So, under federal anti-discrimination law, the answer to today's QATQQ is, generally, fiction.
Note: A United States Supreme Court majority opinion predicted that Title VII, which contains the Pregnancy Discrimination Act, would preempt state law, thereby absolving employers that complied with Title VII from liability for any fetal injury. (Although the concurrence was more skeptical). Further, that same case recognized a narrow safety exception that would allow an employer to remove a pregnant employee from the workplace; namely, in instances in which pregnancy actually interferes with the employee's ability to perform the job.