Made up of mostly fibrous tissue and muscle, the cervix is circular in shape. During pregnancy, the cervix lengthens, serving as a barrier. Labor usually starts two weeks before or after the estimated date of delivery. However, no one knows exactly what triggers the onset of labor. Signs of labor vary from woman to woman, as each woman experiences labor differently.
Labor sometimes begins with amniotic fluid gushing or leaking from the vagina.
Women who experience a rupture of the amniotic sac membranes should contact their physician immediately. The majority of women with ruptured membranes go into labor within 24 hours. If labor still has not begun, a woman may be hospitalized for labor to be induced. This step is often taken to prevent infections and delivery complications. If a woman feels unsure if labor is beginning, she should always call her physician.