Actually, if I understand it correctly, newborns are rather durable. They just squeezed through an opening slightly smaller than their head, at an angle, and twisting all the way through. They ought to be pretty resilient. And looking at the way obstetricians handle them, you'll think they're made of rubber!
I remember being told once that a newborn baby's head must be handled with extreme care because the skull is not yet fully formed.
Also I forgot to ask my brother if there was a machine that goes PING!!! in the room when Harper was born.