Moonbear, hope you read this one... I am due to have my baby in just a little under 5 weeks. Although childbirth isn't a new experience for me (at least in the last 6 years), I truly wonder what triggers labor. Is it something in the brain? Any insight (in simple terms please!) would be good to know. I am well aware of all of the little physical signs that "things are happening", but I want to know a little more on the biological aspect of it.