Once this membrane is stripped, the hormone prostaglandin is naturally released into the mother's body and initiates contractions. Most of the time doing this only once will not immediately start labor. It may have to be done several times before the stimulant hormone is released, and contractions start. The next method is breaking the mother's water, which is also referred to as an amniotomy. The doctor uses a plastic hook to break the membrane and rupture the amniotic sac. Within a few hours labor usually begins. Giving the hormone prostaglandin ripens the cervix, meaning the cervix softens, thins out, or dilates. The drug Cervidil is administered by mouth in tablet form or in gel form as an insert. This is most often done in the hospital overnight. The hormone oxytocin is usually given in the synthetic form of Pitocin. It is administered through an IV throughout the labor process. This hormone stimulates contractions. Pitocin is also used to "restart" labor when it is lagging. The use of misoprostol is also allowed, but close monitoring of the mother is required. Feelings Stripping the membranes: Stripping the membranes only takes a few minutes and causes a few intense cramps. Many women report a feeling similar to urination, others report it to be quite painful. Breaking the water: Having one's water broken feels like a slight tug and then a warm flow of liquid. Pitocin: When the synthetic hormone, pitocin, is used, contractions occur more frequently than a natural occurring birth; they are also more intense. Epidemiology Prevalence of postterm pregnancy may vary between countries due to different population characteristics or medical management. Factors include number of first-time pregnancies, genetic predisposition, timing of ultrasound assessment, and Caesarean section rates, etc. The incidence is approximately 7%. Postterm pregnancy occurs in 0.4% of pregnancies approximately in the United States according to birth certificate data. Notes External links Disorders related to length of gestation and fetal growth