Misoprostol in second trimester termination of pregnancy

Objective: The purpose of this study is to compare misoprostol to oxytocin and prostaglandin E(2) (PGE(2)) in second trimester termination of pregnancy.Methods: Patients between 14 and 24 weeks gestation scheduled for induction were asked to enroll in the study using misoprostol. Comparison was made with historical controls delivered over the last 3 years who received medical induction with (PGE(2)) suppositories or received high dose oxytocin. After pretreatment with acetaminophen, lomotil, and promethazine, a PGE(2) suppository (20 mg) was placed every 4 hours until passage of fetus or treatment failure. Oxytocin was given in dosages that were sequentially infused in 500 mL of D-5 LR over 3 hours each beginning at 50 units/500 mL and increasing an additional 50 units with each subsequent infusion until a maximum of 300 units. Each infusion was followed by 60 mL NS over 1 hour. Treatment failure was defined as undelivered after completion of the 24-hour infusion regimen. Misoprostol was placed into the posterior vaginal fornix every 8 hours until passage of fetus or treatment failure, which was defined as failure to pass fetus within 48 hours. Development of maternal signs or symptoms severe enough to preclude further treatment was also considered treatment failure. Data were collected on use of analgesia, induction to delivery interval, and adverse symptoms.Results: A total of 54 subjects were analyzed. Sixteen were given misoprostol, 21 high dose oxytocin, and 18 PGE(2). Mean induction to delivery times were 1374.2 +/- 1009.5 minutes, 609.2 +/- 515.6 minutes, and 933.6 +/- 1363.7 minutes, respectively. ANOVA with least square analysis showed no difference between groups. There were 3 misoprostol failures, 7 high dose oxytocin failures, and 1 prostin failure. chi(2) analysis of failure rates showed a difference between the 3 groups (P <.05), attributable to the difference between PGE(2) and oxytocin.Conclusions: Induction to delivery interval was not different between the three agents using intravaginal misoprostol of 200 µg every 8 hours. More treatment failures, however, occurred with oxytocin than prostaglandin. In view of lower cost and ease of storage and administration, misoprostol may be a more useful agent.