How much of the focus do you want to be on the preg content?
Evil Goddess by Newface has pregnancy status that causes belly inflation and I think possibly some status debuffs as well.
I remember each character could unlock equippable titles for H-related achievements, and the pregnancy buffs were really some really massive tankyness boost that was great for the early game. I remember trying to grind 100 pregnancies on all my characters so that I could focus on offensive stats on their gear instead.