Pitocin or Oral Misoprostol for PROM IOL

Premature rupture of membranes (PROM) occurs in approximately 8% of pregnancies at term.1 Although onset of spontaneous labor is often prompt after membrane rupture, a delay from PROM to labor is associated with an increased risk of intrauterine infection and its associated maternal and fetal complications. For this reason, the American College of Obstetricians and Gynecologists (ACOG) endorses induction of labor for PROM "if spontaneous labor does not occur near the time of presentation."

The optimal method for PROM induction is less clear. Prior literature has examined the use of Pitocin (Oxytocin), vaginal and oral misoprostol, and dinoprost with mixed results. The TermPROM study found an increased risk of chorioamnionitis and Neonatal Intensive Care Unit (NICU) admission among women treated with vaginal misoprostol for induction.

The postulated link between vaginal misoprostol and chorioamnionitis is the need for vaginal examination for placement of the misoprostol; more vaginal examinations could potentially increase the risk for infection. Utilizing oral misoprostol would eliminate the need for a vaginal exam for administration, thereby potentially mitigating this risk of infection. Currently, vaginal and oral misoprostol as well as oxytocin are used routinely in clinical care based on provider discretion.

Among 7 randomized controlled trials examining the use of oral misoprostol as compared to oxytocin, two found oral misoprostol to result in faster induction to delivery, two found oxytocin to result in faster deliveries, and the remaining three found no difference between the two.3-9 These studies are limited by small sample size, inadequate reporting of patient demographics, varied misoprostol and oxytocin protocols, and inconsistent primary outcomes. Therefore, the utility of oral misoprostol in this population has not been established. Furthermore, its efficacy in specific patient populations is unreported in the literature.

The primary aim of this study is to determine if oxytocin or oral misoprostol results in a shorter interval to delivery after the start of induction among nulliparous women with unfavorable cervical exams with PROM.

Inclusion criteria

• English Speaking
• PROM </= 24 hours with no evidence of labor
• >/= 36 weeks gestation
• Agreeable to induction of labor
• Nulliparous
• Singleton pregnancy
• Vertex presentation
• Cervical dilation </=2 cm AND Bishop score < 8

Exclusion criteria

• Prior cesarean section
• Other contraindication to vaginal delivery
• Intrauterine Fetal Demise
• Major Congenital Anomaly
• Intraamniotic infection diagnosed at time of admission
• 36 weeks - 36 weeks and 6 days with unknown Group B Strep (GBS) status