RESUMO
OBJECTIVE: The ideal agent for induction of labor when the cervix is unripe is unknown, but several prostaglandin derivatives are currently available. Recently, the synthetic prostaglandin El derivative misoprostol has been used with good success for induction of labor. The cost of misoprostol is only a fraction of the cost of the traditionally used dinoprostone. We conducted a prospective, randomized trial comparing the efficacy and safety of misoprostol and dinoprostone for induction of labor. MATERIAL AND METHODS: One hundred and twenty-three women with an indication for induction of labor and an unfavorable cervical score and intact membranes were randomized to receive either one dose of misoprostol 100 meg or two doses of dinoprostone 3 mg at eight hour intervals, in the posterior vaginal fornix. RESULTS: Fifty-one women received misoprostol and 60 dinoprostone. Twelve women dropped out of the study after randomization, thereof 11 from the miso notprostol group due to a too favorable cervical score (n=9) and ruptured membranes (n=2). The mean time from induction of labor to delivery was 548 and 1,087 minutes in the misoprostol and dinoprostone groups, respectively (p<0.05). The need for oxytocin was 40% in the misoprostol and 71% in the dinopro notstone group (p<0.05). There was no difference in mode of delivery between the groups; 21.6% and 25% were delivered by cesarean section in the miso notprostol and dinoprostone groups, respectively. The incidence of fetal distress as evaluated by brady notcardia, tachycardia or late decelerations was similar in both groups. The occurrence of meconium was 41% and 20.5% in the misoprostol and dinoprostone groups, respectively (p=0.056). The incidence of uterine hyperstimulation was 59.6% in the misopro notstol group and 18.6% in the dinoprostone group (p<0.05). The Apgar score at one minute was 6.6 and 7.6 and at five minutes 8.5 and 9.0 in the misoprostol and dinoprostone groups, respectively (p=0.048 and 0.037). When only vaginal births are examined there was no difference in Apgar score at one and five minutes (p=0.11; p=0.21). CONCLUSIONS: Intravaginal misoprostol and dinopro notstone are both effective in inducing labor when the cervix is unripe. Delivery is faster with this dose of misoprostol compared to dinoprostone and there is less requirement for further augmentation of labor with oxytocin, but the incidence of uterine hyperstimulation is higher. This was, however, not reflected in an increased incidence of fetal distress, cesarean section or adverse neonatal outcome. The ideal dose of misoprostol for induction of labor remains to be determined.
