Can labor start while sleeping?

So clearly it reaches it's peak during the dark hours, making us more likely to go start contracting in the evening. Melatonin doesn't just help trigger labour but also helps our uterine muscles to work more effectively during the final stages of birth.

sleeping position delay labor
Spending most of your time in bed, especially lying on your back, or sitting up at a small angle, interferes with labor progress: Gravity works against you, and the baby might be more likely to settle into a posterior position. Pain might increase, especially back pain.