By search term Pregnancy is actually a very common kink, people generally don't talk about it because some people wrongly demonize it. but it's as common an interest as big tits. I don't mind if the game doesn't include it since not every game needs to be preg themed, but I like me some nice hot women carrying my progeny. Theres nothing wrong with that. niche kink would be more like scat or even furry since less people look up those terms.