I've heard about fracturing during giving birth. i did mine falling off a bicycle. couldn't wear slacks for almost a year, nor sit in a sideways seat on the bus. standing or laying down was fine. i was told i put my tail bone out of joint. didn't find out till i moved up to Colorado that i'd really fractured it.
me old bones aren't healing well now, so that's the only reason i'm a bit worried. as long as nothing moves or pinches, i guess i will be all right.