Washington, DC -- Revised guidelines on when and how to induce labor in pregnant women were issued today by The American College of Obstetricians and Gynecologists (ACOG). The guidelines provide physicians with guidance regarding which induction methods may be most appropriate under particular circumstances, as well as the safety requirements, and risks and benefits of the different methods. ACOG's Practice Bulletin "Induction of Labor" is published in the August 2009 issue of Obstetrics & Gynecology.
The rate of labor induction in the US has more than doubled since 1990. In 2006, more than 22% (roughly 1 out of every 5) of all pregnant women had their labor induced. The goal of labor induction is to artificially stimulate uterine contractions so that pregnant women can deliver vaginally. As with all procedures, the risks must be weighed against the benefits to the woman and the fetus.
"There are certain health conditions, in either the woman or the fetus, where the benefit of inducing labor is clear-cut," says Susan Ramin, MD, from the University of Texas Medical School in Houston who helped lead the development of ACOG's Practice Bulletin. "And, there are some nonmedical situations in which induction also may be prudent, for instance, in rural areas where the distance to the hospital is just too great to risk waiting for spontaneous labor to happen at home." In circumstances like these, the ACOG recommendations say the gestational age of the fetus should be determined to be at least 39 weeks or that fetal lung maturity must be established before induction.
Cervical ripening is the first component to labor induction. If the cervix is not sufficiently dilated, then drugs or mechanical cervical dilators should be used to ripen the cervix before labor is induced. Once the cervix is dilated, labor can be induced with oxytocin, membrane stripping, rupture of the amniotic membrane, or nipple stimulation. Misoprostol, a medication for peptic ulcers, is a commonly used off-label drug that both ripens the cervix and induces labor. The ACOG guidelines indicate that inducing labor with misoprostol should be avoided in women who have had even one prior cesarean delivery due to the possibility of uterine rupture (which can be catastrophic).
According to ACOG, there are a number of health conditions that may warrant inducing labor but physicians should take into account maternal and infant conditions, cervical status, gestational age, and other factors. Some examples in which labor induction is indicated include (but are not limited to) gestational or chronic hypertension, preeclampsia, eclampsia, diabetes, premature rupture of membranes, severe fetal growth restriction, and postterm pregnancy.
"There are certain situations where labor induction is contraindicated," says Dr. Ramin. These situations include (but are not limited to) transverse fetal position, umbilical cord prolapse, active genital herpes infection, placenta previa, and women who have had a previous myomectomy (fibroid removal) from the inside of the uterus, according to ACOG.
"A physician capable of performing a cesarean should be readily available any time induction is used in the event that the induction isn't successful in producing a vaginal delivery," notes Dr. Ramin. Although rare, there are potential complications with some methods of labor induction. "These guidelines will help physicians utilize the most appropriate method depending on the unique characteristics of the pregnant woman and her fetus."
Practice Bulletin #107, "Induction of Labor," is published in the August 2009 issue of Obstetrics & Gynecology.