But the truth is, there is still a lot of mystery surrounding pregnancy and birth. For instance, did you know that we still don't know what exactly causes labor to start?
Luckily, not all things about pregnancy need to remain a mystery. Discover six wow-inspiring ways your body changes during pregnancy. 1. Your uterus is one tough cookie. The force inside a woman's uterus from pushing with a contraction translates to 397 pounds of pressure per square foot, or 2.8 pounds of pressure per square inch on her baby's head.
2. What was that noise? It's painful yet true -- the first time a woman delivers a