You can get the slave route. It's broken, but not completly...
Just follow these steps (apperantly not all of this is necessary, but this worked for me):
- get a high lewdness (mine was arround 150, but much lower is fine too)
- get pregnant and birth the bug-fly from the temple dungeon a bunch of times (normal hospital)
- Birth the bug-fly in the slum hospital (no need apperantly)
- get pregnent from the bug-fly, but don't go to the hospital. Instead get a human partner and your baby will turn into humanoid (the bug-fly is just there to get around the bugged womb-status)
- Birth your humanoid baby in the normal hospital
I attached my save right before step 5, so you can see it yourself (Most of the normal stuff has been done with some cheats/save-editor for money and atk).