A randomized trial of vaginal prostaglandin E2 for induction of labor. Insert vs. tablet

To compare the efficacy and safety of a prostaglandin E2 (PGE2) vaginal insert with PGE2 administered as a vaginal tablet.

A randomized, observational study was performed. Women requiring induction of labor were randomly assigned to receive either a 10-mg PGE2 vaginal insert (group 1, n = 100) or 3-mg PGE2 tablets twice at six-hour intervals (group 2, n = 100). The primary efficacy outcome variable was vaginal delivery within 24 hours of insertion. The criteria for safety were the occurrence of uterine hyperstimulation, abnormal fetal heart rate patterns, use of beta 2-sympathomimetic drugs and fetal outcome.

No differences in terms of vaginal delivery or cesarean section within 24 hours of induction were found. The cesarean section rate was 21% in group 1 and 22% in group 2. The interval from insertion of the induction agent to the onset of regular uterine contractions and the insertion-to-delivery interval were not different between the two cohorts. No difference in the frequency of uterine hyperstimulation, use of beta 2-sympathomimetic drugs, abnormal fetal heart rate patterns, fetal outcome, or oxytocin and analgesic requirements were found. In seven of eight patients in group 1 who experienced uterine hyperstimulation, removal of the insert was sufficient to stop it, whereas in group 2, of nine cases, eight needed medical interventions to end hyperstimulation (P = .003).

The continuous release of PGE2 from the vaginal insert permits controlled induction of labor, and easy removal of the drug in cases of uterine hyperstimulation is possible.