Labor Patient Advisor Labor Labor is the process by which contractions of a pregnant uterus cause birth. The baby moves down the birth canal and is born. Delivery of the placenta is the last part of labor.
Every labor is different.
How long it lasts and how it progresses differ from woman to woman and from birth to birth. There are, however, general guidelines for labor that a doctor uses to decide whether it is progressing normally. If it is not progressing normally, you may need medical assistance or a cesarean section. No one knows exactly what starts the labor process. However, we do know that certain hormones, such as oxytocin and prostaglandin, cause uterine contractions and the thinning of the cervix.