The four stages of the childbirth process are based on changes in the uterus and cervix as labor progresses. The beginning and end of each stage are described below: First Stage of Labor. Begins at the onset of labor and ends when the cervix is 100 percent effaced and completely dilated to 10 centimeters. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.