I don't recall seeing this before but I was thinking that pregnancy should be a trait that effects your whoring stats in some way. I know there are prego fetishes and people just love to watch prego chicks do porn. (I used to build websites for people and the most profitable one I ever built was a prego porn site) So when a girl gets knocked up, maybe it should effect the chick in both a positive and negative way. It should maybe cut her health in half but also be attractive to a certain type of customer. She gets tired more easy but makes a little more money maybe. 30 weeks is a long time to carry a poop factory around while the chick is still at full whoring capacity with no ill effects to either the mother or baby.
Maybe the game could keep track of how many customers she has over the life span of the pregnancy and when the baby is born it might have more or less issues based on how well she's treated etc. etc. So do you keep her working at full capacity and risk the life of your whore, the kid, or lighten the load and pamper her a bit so she willingly hands over the kid with good stats so you can put him/her to work?
Another idea
Different types of whores--
Right now I consider the majority of the girls in the game to just be simple whores. Day in and day out, but how about making some of the a different class, like call them "Escorts", yeah they do usual screwing, but these girls are trained to do other things, they can sing, dance, a girl so sweet and epic a politician wouldn't mind having one on his arm. These girls are expensive, and demand expensive accommodations but they also make the money, butter up the powerful people that hire them and can/could be relied upon to handle things if you can't. Retire to a matron position?
I had a few other ideas but I'm forgetful in the extreme sometimes.
CHZ