Midtrimester pregnancy termination: a randomized trial of prostaglandin E2 versus concentrated oxytocin

The purpose of this study was to determine whether a concentrated oxytocin infusion can reliably effect uterine evacuation in the midtrimester and whether such an infusion is associated with fewer side effects than prostaglandin E2 vaginal suppositories.

Patients received either prostaglandin E2 (n = 42) or oxytocin (n = 45) for indicated midtrimester abortions in a prospective, randomized trial. Treatment consisted of either prostaglandin E2 vaginal suppositories (one every 4 hours) or infusions of an escalating concentration of oxytocin (one every 4 hours). Unless delivery had occurred or was imminent after 24 hours, the agent was considered to have failed, and patients were crossed to the alternative method.

Delivery indications were similar between the two groups. There were 6 (14%) first-agent failures with prostaglandin E2 and 9 (20%) with oxytocin (p = 0.48). Considering the failures and subsequent crossovers, 103 patient trial regimens were completed. Fever, nausea, vomiting, and diarrhea were more frequent with prostaglandin E2 (p < 0.005).

Concentrated oxytocin is a satisfactory alternative to prostaglandin E2 for midtrimester abortion.