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 health care provider uses to decide whether it is progressing normally. If it is not progressing normally, you may need medical assistance or a cesarean section. If any signs of labor occur before 37 weeks of pregnancy, the labor is considered preterm. You should call your health care provider right away if you have any signs or symptoms of labor before 37 weeks.