17-hydroxyprogesterone caproate for preterm rupture of the membranes: a multicenter, randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Preterm rupture of membranes (PROM) is associated with an increased risk of preterm birth and neonatal morbidity. Prophylactic 17-hydroxyprogesterone caproate (17OHP-C) reduces the risk of preterm birth in some women who are at risk for preterm birth. We sought to test whether 17OHP-C would prolong pregnancy or improve perinatal outcome when given to mothers with preterm rupture of the membranes. STUDY DESIGN: This is a multicenter, double-blind, placebo-controlled, randomized clinical trial. The study included singleton pregnancies with gestational ages from 23(0/7) to 30(6/7) weeks at enrollment, documented PROM, and no contraindication to expectant management. Consenting women were assigned randomly to receive weekly intramuscular injections of 17OHP-C (250 mg) or placebo. The primary outcome was continuation of pregnancy until a favorable gestational age, which was defined as either 34(0/7) weeks of gestation or documentation of fetal lung maturity at 32(0/7) to 33(6/7) weeks of gestation. The 2 prespecified secondary outcomes were interval from randomization to delivery and composite adverse perinatal outcome. The planned sample size was 222 total women. RESULTS: From October 2011 to April 2014, 152 women were enrolled; 74 women were allocated randomly to 17OHP-C, and 78 were allocated randomly to placebo. The trial was stopped when results of a planned interim analysis suggested that continuation was futile. The primary outcome was achieved in 3% of the 17OHP-C group and 8% of the placebo group (P = .18). There was no significant between-group difference in the prespecified secondary outcomes, randomization-to-delivery interval (17.1 ± 16.1 vs 17.0 ± 15.8 days, respectively; P = .76) or composite adverse perinatal outcome (63% vs 61%, respectively; P = .93). No significant differences were found in other outcomes, which included rates of chorioamnionitis, postpartum endometritis, cesarean delivery, individual components of the composite outcome, or prolonged neonatal length of stay. CONCLUSION: Compared with placebo, weekly 17OHP-C injections did not prolong pregnancy or reduce perinatal morbidity in patients with PROM in this trial.