Amniotomy is the official term for artificially breaking the bag of waters during labor. It is believed that breaking the bag of waters will help to speed up an otherwise slow labor. Amniotomy is part of the Active Management of Labor practiced in some hospitals.
Amniotomy is performed by a midwife or doctor. A long, thin instrument with a small hook on the end is inserted into the vagina and through the cervix so it can catch and rip the bag of waters. To perform an amniotomy, the cervix must be dilated enough to allow the instrument through the cervix, generally at least a two.
Unlike other medical methods of starting labor, amniotomy does not add synthetic hormones to your labor. Instead it seems to stimulate your body’s own labor process. Amniotomy allows the use of an internal electronic fetal monitor.
Amniotomy alone is unpredictable, it may take hours for labor to start. Because it increases the risk for infection, most caregivers use amniotomy in combination with synthetic oxytocin. Birth does happen faster when amniotomy is combined with synthetic oxytocin than when amniotomy is used alone.
Risks for Mother
- Increases the risk for infection. This risk is increased with length of time the waters are broken and with vaginal exams.
- Because of the infection risk, a time limit is given by which the mother must give birth. As the time limit approaches attempts to progress labor will become more aggressive.
- The fore waters equalize pressure on the cervix allowing it to open uniformly. When they are broken, the mother increases her chances of having uneven dilation.
Risks for Baby
- Increases the risk of umbilical cord compression.
- The fore waters equalize pressure on the baby’s head as it presses against the cervix. When they are broken, the pressure on the baby’s head may be uneven causing swelling in some parts.
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.