Well, the birth process, also known as parteration, can also be broken down into three stages. We have stage number one, which lasts about 12 hours. We have stage number two, which lasts from anywhere from 20 minutes to 1 hour. And then we have stage three, which lasts about ten to 15 minutes. So let's begin with stage one. So in stage one is when special hormones are released by the body and they stimulate the contraction of the walls of that uterus.