When it come to pregnancy I see a few different possibility. The first, and my favorite, is to regulate it to the realm of fluff. Have pregnant characters be no different mechanically then non pregnant characters though you may raise a few eyebrows adventuring like that all the characters who could get pregnant are preds so in anyone gives you shit you could just make them into shit. Another possibility is have them lay eggs and leave those eggs with trusted npc's. We have two fish women, one dracotaur and a shapeshifter who could all lay eggs if they want to. Just throwing it out there, ultimately its up the players who would be effected of course.