Clinical Question

Is induction or expectant management more appropriate for premature rupture of membranes at term (PROM)?

Evidence-Based Answer

Induction of labor in patients with PROM does not increase the rates of cesarean delivery or operative vaginal delivery. Among patients who are induced there is a slightly lower incidence of chorioamnionitis (relative risk [RR] 0.74; 95% confidence interval [CI], 0.56 to 0.97) and a lower rate of infant admissions to the neonatal intensive care unit (NICU; RR 0.73; 95% CI, 0.58 to 0.91). The evidence in this study shows induction to be a reasonable option with no increased risk of operative delivery or of harm to mother or neonate.

Practice Pointers

PROM is defined as rupture of membranes that occurs at term but before the onset of labor. It occurs in approximately 8 percent of pregnancies; 50 percent of patients deliver within five hours of membrane rupture, and 95 percent of patients deliver within 28 hours.¹ The most significant risk of PROM is intrauterine infection, which increases with duration of rupture. Fetal risks include cord compression and ascending infection.¹ Historically, two approaches have been used: induction or expectant management. Induction involves intervening to induce labor at diagnosis or within six to eight hours of rupture of membranes. Expectant management allows the onset of labor to occur spontaneously without intervention.

Dare and colleagues performed a systematic review of randomized controlled trials to compare outcomes of induction with oxytocin (Pitocin) or prostaglandin E2 gel (Prostin E2) versus expectant management of PROM in low-risk patients. They identified 12 trials with a total of 6,814 women. Maternal mortality was examined in one study and there were no maternal deaths in either arm. There was no difference between the two management approaches in the rates of cesarean delivery or of operative vaginal deliveries. Fewer women who underwent induction developed chorioamnionitis. Compared with expectant management, one case of chorioamnionitis will be avoided for every 50 women undergoing induction for PROM. Also, there were fewer cases of endometritis in the induction groups (RR 0.30; 95% CI, 0.12 to 0.74; four trials, 445 women).

Time from rupture of membranes to birth was reduced by 13 hours in patients receiving oxytocin and by eight hours in those receiving prostaglandin compared with expectant management. Patients who underwent expectant management also had higher rates of dissatisfaction. Only one study reported uterine rupture, with one rupture in the prostaglandin arm of that study and none in the expectant management arm. This difference was not statistically significant (95% CI, 0.12 to 68.50).

There were fewer NICU admissions in the induction group. One NICU admission was avoided for every 20 women induced for PROM. In one large study, neonates born in the expectant management group were more likely to spend more than 24 hours in the NICU. However, there were no statistically significant differences between the two groups regarding infant success of breast-feeding or incidences of cord prolapse and neonatal infection.

A meta-analysis² published in 2005 found that misoprostol (Cytotec) was as safe and effective as oxytocin for induction of patients with PROM.