If I understand this correctly, you're enquiring about three things here.
One is the miscarraige mechanic. If Lona is pregnant and you take a crapton of damage (or keep getting punched in the gut and r4p3d), don't eat right, sleep and bathe regularly, the baby's health will start to deteriorate rapidly. So don't go smashing skellies at the graveyard. Don't chug health potions and expect the baby to survive. It needs food, not a chemical imbalance.
Soups are good - they also raise Lona's mood - as is Noer Tea, somehow. If you don't look after yourself, the baby will suffer. Too much of it and too often and miscarraige procs, ergo: lump of flesh. The other way is to get pregnant from a beast. I think there's a horse somewhere you can do that with but they generally don't like it when you assault a horse. Even if you get away with a animal's baby in you, it's a guaranteed miscarraige.
As for your question regarding Elise's "assisted" pregnancy and birth basically all you can do is sleep, eat, crap and masturbate. Not sure if you can actually escape though. Going through with the birth takes a VERY long time.
The only other way to give birth is to let it happen wherever you are. You'll know when this happens.