Oxytocin for labor induction

Induction of labor has increased from 9% to 18% of all U.S. deliveries in recent years. Several useful oxytocin induction protocols are available, both from the ACOG Practice Bulletin #10 and institutional sources. Higher-dose protocols tend to result in fewer cesarean deliveries for dystocia but more "fetal distress." There is no consensus as to which protocol is best, and the clinician is advised to understand the trade-offs involved and how those trade-offs could relate to the clinician's local situation. Given the availability now of prostaglandin agents for induction with an unfavorable cervix, the advantage of less hyperstimulation in low-dose oxytocin protocols may become increasingly important. The most important risks include hyperstimulation (frequent but usually brief and well-tolerated), failed induction (occasional and important), and uterine rupture in some studies (rare but dangerous). Pain was not a sensitive indicator of uterine rupture in a large 1989 study. Fetal heart rate changes were much more likely to herald uterine rupture in that study. Oxytocin's greatest weakness is that some patients will not respond well to it, especially with marked cervical unfavorability. However, given an individual patient whose uterus will respond adequately to this drug, oxytocin has the advantage of short half-life and the option for prompt cessation if desired. Intrauterine pressure catheters with oxytocin usage are usually well-worth their minor risks. Current ACOG literature lists induction of labor in the setting of one or more previous low-transverse cesarean deliveries as necessitating "special attention" and "close patient monitoring." The well-informed clinician will be familiar with the issues involved.