The womb is a circle of power where a force of nature is formed. The womb has the power to create life. Life is a force of nature, and the circle of life starts in the womb.
Now pretend you are the pregnant woman. You need to force that baby out of you with such force that the baby comes flying out, so you grab hold of your special saber (せい)! You close your eyes, breathe and feel the force of the saber entering your body. Then the baby is forced right out!