Stages of labor and delivery: Know what to expect

After around 40 weeks of growing and carrying a new life, a pregnant woman's hardest work begins -- the process of labor.

Labor has been compared to pushing a grand piano across a warehouse floor. It is strenuous, exhausting work.

The contractions of labor are the result of the tightening and releasing of the uterus. Effacement is the thinning or shortening of the cervix to prepare it to dilate and let the baby through. The cervix gradually disappears as it is being pulled up by the contractions. Dilation is the opening of the cervix from its closed state to a diameter of 10 centimeters. These terms are used to gauge the progress of labor, signaling the changing of phases and stages.

The first stage, called cervical dilation, has three phases. Second stage is the actual pushing phase. Third stage comes after the birth of the baby and continues through the delivery of the placenta. And the fourth stage is the initial recovery period for the mother.