Not all mollies die after giving birth. Some do because they get to stressed out while dropping off their fry. I would think that with a proper diet and good water conditions the mollies have a better chance. Mine seem to not have a problem, always give birth at night though so when I wake up I'm just in time to see the last fry be eaten . Won't happen again though. Setting up a take to move my pregs to after a few weeks. Then I will in theory be able to save the fry.