There are many times when inducing labor is required to preserve the health of the fetus or the mom. Labor may also be induced for women who've already had a baby and live far from a hospital. In 2006, nearly one in five women were induced in the United States, the American Congress of Obstetricians and Gynecologists (ACOG) states. Three types of drugs are commonly used (as of 2010) for labor induction.
Dinoprostone (Cervidil, Prepidil)
Dinoprostone is a prostaglandin gel that softens and thins the cervix, making dilation easier. Prostaglandins work by inducing uterine contractions. In some women, dinoprostone alone gets some women into a good labor pattern, but it's more often used as the first part of a one-two punch: cervical ripening followed by induction with oxytocin. Prepidil is placed intracervically, while Cervidil is placed in the vagina. Cervidil is attached to a cord that makes it easy to remove if hyperstimulation, uterine contractions that are too strong and too close together, occur. Cervidil is removed after 12 hours or when an adequate labor pattern is established.
Prepidil is often administered six hours apart for a total of three doses in 24 hours, Josie Tenore, M.D., states in a 2003 article in "American Family Physician" entitled "Methods for Cervical Ripening and Induction of Labor." Women receiving either drug require fetal monitoring for several hours after administration, to watch for hyperstimulation or fetal distress. Uterine rupture has occurred from hyperstimulation after dinoprostone use. Other side effects of dinoprostone include nausea, vomiting, diarrhea, fever, back pain and a slight increase in fetal heart rate abnormalities.
Misoprostone (Cytotec)
Misoprostone, sold as Cytotec, is a different-category prostaglandin drug than dinoprostone and acts as an anti-progesterone agent. Because progesterone inhibits uterine contraction, Cytotec enhances uterine contraction. Cytotec tablets are inserted into the vagina to induce cervical ripening. Cytotec is used off-label for labor induction, which means clinical trials have not been done to assess its effectiveness and risks in labor. The drug is FDA-approved for use in treating gastric ulcers. ACOG guidelines state Cytotec should not be used for women with uterine scarring, such as women with a previous cesarean delivery, as uterine rupture may occur.
Oxytocin (Pitocin)
Oxytocin stimulates uterine contractions when the cervix is soft and ready to dilate. Oxytocin, commercially sold as Pitocin, is usually given intravenously via a pump that delivers precise amounts of the drug. The amount is gradually increased until the desired number and strength of uterine contractions is reached. Pitocin infusion can be stopped or slowed if problems occur. Risks of oxytocin include uterine hyperstimulation, including inadequate relaxation of the uterus between contractions, uterine rupture, fetal distress and maternal low blood pressure. Constant fetal monitoring and recording of blood pressure is required when a patient is receiving Pitocin.
