During a vaginal exam, your midwife will insert her finger through the cervix and pull the bag of waters away from the cervix. This causes your body to increase production of prostaglandins which is believed to help ripen the cervix and stimulate labor. This can be uncomfortable and may cause some mild bleeding the rest of the day. It can only be done if your cervix is dilated enough for the midwife to insert her finger.
In the studies that have been done, women who have their membranes stripped are less likely to use chemical induction methods because they are less likely to go beyond 42 weeks. However, no studies have determined if it decreases rates of cesarean or other outcomes. It is performed during an office visit, so allows you to stay home as long as possible.
Overall sweeping the membranes appears safe. It causes mild discomfort for the mother, and an increased tendency for pre-labor rupture of the membranes. There is no increased risk of infection.
Goer, Henci. The Thinking Woman’s Guide to a Better Birth. 1999. New York: The Berkley Publishing Group.
Enkin, Keirse, Nilson, Crowther, Duley, Hodnett and Hofmeyr. A guide to effective care in pregnancy and childbirth Third Edition. 2000. Oxford: Oxford University Press.