It's not so much Important as it is a very welcome surprise.
At this point I'm used to H-Games not having great gameplay, so when comes around it's like, "Oh! Neat!"
In a H-Game its not IMPORTANT.
BUT, it's always a nice addition. If I like the porn and I like the story I'm more likely to play your game longer for sure.
Everything about pregnancy is hot for me. The impreg and breeding kink, the pregnancy sex, hell I've even read a comic that did birthing pretty well too.
Depends on how interesting the game is really? You can have long breaks with no smut if what's in between them is captivating.
But if you're clearly a smut game for the smut, well then get to the smut!
Yes, cause I'm not here for the story for most of these. The majority of them aren't super captivating reads. I'm here for the goon. So show me which option gets to the sex scene yes please.