Labor is a series of processes by which the products of conception are expelled from the mother’s body. However, there are other milestones that need to be addressed. The birth of a newborn results in the expansion of a family. A couple will enter the labor suite and upon discharge a new family emerges.

The cause of labor is unknown; however, there are several theories. One theory states that there is an increased sensitivity of the myometrium to oxytocin, whereas another states that there is a decrease in the progesterone levels. A third theory states that there is an increase in the uterine irritability as a result of stretching from the expanding contents.

During the last few weeks of pregnancy a number of changes may indicate that the time for labor is approaching. Primigravidas have lightening occur about 10-14 days before delivery. Lightening means that the fetal presenting part descends into the true pelvis. The woman usually feels pressure on her bladder and reports more frequent urination. However, her breathing is much easier because the fetus is no longer pressing on the diaphragm. A phenomenon called nesting occurs during this time, and some women report a surge of energy before labor. The increased energy level usually occurs in 24 to 48 hours before the onset of labor. It is theorized to be the result of an increase in epinephrine release and a decrease of progesterone.