I'm not sure if this was suppose to happen, but can walk you thru it to mimic it. I do it all the time. in 0.2.32.03 I have noticed that if you're "pregnant" and your water breaks while in the apartment while naked for nightwear. the MC leaves the apartment and goes to the hospital to give birth while naked. From there you're able to move around outside the apartment while naked.
1: get pregnant
2/3: go to apartment take all clothing off to be naked when you sleep.(if not using the cheat menu)
2/3:remove all clothing you're currently wearing while in the apartment(if using the cheat menu)
4: use the cheat option or idle by to pass days till water breaks
the MC is now naked and outside of the apartment after birth. no hospital garment or anything.