@vagina_museum i wonder if it's coincidence that a few years later Heinlein described childbirth on a spaceship being assisted by a well-timed sudden increase in the artificial gravity field. (The birthing position was not supine though.) I'm sure he was trying to be helpful or modern or something, but, oh my. Of course this was Time Enough For Love and it was probably one of the less-problematic things in it for a modern reader. I'm guessing because I don't dare read it again in this century…