The answer is if the woman is an actress and her character is pregnant at the same time she’s pregnant in real life.
It happened most famously to Lucy Ball and Lucy Ricardo. Lucille Ball was pregnant with her son in real life at the same time her character was preggers.
And it’ll be true this season as well: On her new CBS sitcom "Accidentally on Purpose," Jenna Elfman plays a character who unexpectedly gets pregnant. Since she was going to be going through maternity wear anyway, the actress decided this was the perfect time to get pregnant for real, according to People magazine. Jenna and husband Bodhi Elfman are currently expecting their second child. No word yet as to who the on-screen dad is…
— Chuck Ross