Don't feed the tigers. In the pre-modern world, when humans lived in the wilds, women had to go on with daily life regardless of pregnancy. If they were out in a field and a tiger appeared, they still needed to be able to run away with all the stamina they possessed--EVEN if they were in labor. Our biology is hard-wired to stop or stall labor if we are sending out signals of fear and panic, to protect us and our young!