The magical babby thing, whereby a child or infant saps all personality out of a formerly-actualized female character. I don't mean people having kids or wanting them; these are natural human desires/events and entertainment would be pretty unrealistic without them. I mean when a character has shown no desire for a child, and has a number of other interests and ties that have been consistent. Then some goddamn knuckle-dragging writer decides that her fangs need to be pulled, so he creepily forces a baby on her that obliterates her past self because she is now Mommy, Nothing But Mommy.
I'm talking about egregious weirdness here. Take the reboot of Battlestar Galactica for example. Kara Thrace is a career pilot who cares for her squadmates, likes being rowdy, has ambivalent family relationships, tries to untangle some very complicated feels with the Adamas, and is pretty wholeheartedly dedicated to saving the universe. She's a complete person who never really expresses an interest in family life. Then a Cylon abducts her, holds her captive in his house, tries to give her Stockholm syndrome, and still fails to make her love him. But when she brings the child he also abducted, held captive, and tried to brainwash back to her mother, she goes all flat and suicidal because OMGZ LIFE WITHOUT BABBY IS NOTHING. All that stuff I listed about her? Gone. She doesn't care about saving the human race, she just wants to be a vessel. This is not wanting a family, this is becoming hollow. It was subtractive (Kara - personality) instead of additive (Kara + characteristics + new goal).
See also, Eureka, in which a mad scientist ******** steals his ex's DNA, clones her, and has a family with the clone. Then the clone dies, the real ex's parents see news headlines and are traumatized, and the still-living ex has to turn up to sort it all out. She's got her own life now, she's got her career and friends and loving family, and she is pissed as hell at the violation her mad-scientist ex perpetrated. She just wants to deal with this and go home, and reassure her traumatized parents. But everyone lays a goddamn guilt trip on her to raise this boy who is not her son, because oh her clone and her ex, and he's a child! Never mind her mad-scientist ex violated her, never mind he did it because she broke up with him because she didn't want to marry/procreate, never mind that the kid will be wigged out because it's not really his mom. Oh, no, we all have to browbeat a victim of a heinous crime until she gives up her life and becomes Mommy Two. Because that's okay and sane. Secret cloning is a-ok, but this lady not wanting to be press-ganged into conformity must be corrected with a kid.
Once Upon a Time is guilty of this too, but I can't speak much to it because I turned the first episode off in disgust because this is messed up. Erasing these female characters with children is ten kinds of ******** and unnecessary. Moms are people too, okay, and it's fine if a character does not ever change her mind. This pod-people thing is incredibly sinister and offputting.