They were randomized evenly to receive MVI 200 or the DVI (Cervidil, which delivers 10 mg of the drug). The inserts were placed transversely, high in the posterior vaginal fornix, and left in place until the onset of active labor, other events requiring removal, or 24 hours.
The main indications for labor induction were prolonged pregnancy, hypertensive complications, and oligohydramnios, Dr. Wing.
In analyses with censoring for cesarean delivery and for nondelivery, women in the MVI 200 group had a median time to vaginal delivery that was 11.3 hours shorter than for the DVI group (P less than .001). The difference was 6.5 hours in parous women and 14.0 hours in nulliparous women.
The MVI 200 group also had a shorter median time to any delivery (18.3 vs. 27.3 hours) and a shorter median time to active labor (12.1 vs. 18.6 hours), and this group was less likely to be given oxytocin before delivery (48% vs. 74%; P less than .001 for all three outcomes).
The rate of cesarean delivery was 26% in the MVI 200 group and 27% in the DVI group, a nonsignificant difference; however, the latter value fell short of the anticipated 30% needed for adequate power. "The indications for c-section were similar between the groups," Dr. Wing noted.
The MVI 200 group had a higher incidence of intrapartum drug-related adverse events (13% vs. 4%) – mainly driven by fetal heart rate disorder and abnormal labor affecting the fetus (arrest of dilatation or descent).
Rates of maternal postpartum drug-related adverse events were identical; rates of neonatal drug-related adverse events were low generally but higher with MVI 200 (0.7% vs. 0.1%).
Dr. Wing disclosed that she is a principal investigator for and consultant to Ferring Pharmaceuticals. The trial was supported by Ferring.