【正文】 al retrospective studies have specifically addressed the safety of misoprostol use for secondtrimester induction in the case of a prior cesarean delivery. In one of the largest retrospective studies on the subject, 188 women with a previous cesarean delivery underwent induction of labor between 17 and 24 weeks of The dose of misoprostol was 400 181。g orally together with 400 181。g vaginally for the first dose followed by 400 181。g vaginally every 6 hours for a maximum of 5 doses. The main outes included hemorrhage requiring transfusion, postabortal infection, retained placenta, and uterine rupture. There was no evidence that a previous cesarean delivery affected the incidence of plications. Similar results were found in another study of 80 women undergoing termination of pregnancy between 13 and 26 weeks of gestation for a variety of reasons with 1 or more cesarean section Misoprostol, 400 181。g, was administered to women up to 20 weeks of gestation and 200 181。g for women greater than 20 weeks of gestation, vaginally or sublingually, every 6 hours up to 24 hours. The mean induction to abortion interval was hours and was not statistically different between women with and without a prior cesarean delivery scar. There was no case of uterine rupture or scar dehiscence. No statistically significant differences were found in rates of inplete abortion, blood loss, or sepsis.Cervical Ripening and Induction of Labor With a Viable FetusCompared with placebo, misoprostol causes cervical ripening before induction with ,82 When used for cervical ripening, misoprostol can be administered orally, sublingually, or vaginally, although there is more evidence for vaginal ,84 A monly used dose is 25 181。g administered vaginally every 4 hours as needed, with a maximum dose of 150 Doses are withheld if contractions are more frequent than every 4 minutes. Electronic fetal heart rate monitoring is used to evaluate fetal status 20 minutes before administration and continued for 4 hours after each dose.Misoprostol has also been shown to be effective for induction of labor with a viable ,87 The Cochrane Pregnancy and Childbirth Group reviewed randomized trials paring vaginal misoprostol with placebo, oxytocin, or prostaglandin E2 for cervical ripening or induction of a viable fetus in the third Primary outes included rate of vaginal delivery within 24 hours, incidence of uterine hyperstimulation with associated fetal heart rate changes, rate of cesarean delivery, and risk of serious adverse event in mother or fetus. Vaginal misoprostol was found to be more effective than prostaglandin E2 or oxytocin for inducing vaginal delivery within 24 hours. However, uterine stimulation with associated fetal heart rate changes was more mon in the group of women receiving misoprostol than in women receiving either oxytocin or prostaglandin E2. Cesarean delivery rate data were conflicting with a trend toward decreased cesareans for failure to progress in labor and increased cesarean deliveries for fetal distress in the misoprostol group. There was no difference in serious neonatal or maternal mortality between women receiving misoprostol and women who received prostaglandin E2 or oxytocin。 however, most studies were underpowered for this assessment. Optimal dosing of misoprostol that will achieve effective induction without uterine hyperstimulation and resultant fetal heart rate changes has been the topic of many studies. As with cervical ripening, an effective dose of misoprostol without high rates of uterine hyperstimulation is 25 181。g administered every 4 to 6 ,85Postpartum HemorrhageMisoprostol has been used both as prevention and treatment of postpartum hemorrhage secondary to its uterotonic properties. Several randomized, controlled trials88–90 and a large, prospective, observational study91 have examined the use of misoprostol as an agent for the prevention of postpartum hemorrhage. There are insufficient data to support the use of misoprostol as a primary preventive measure for postpartum hemorrhage when conventional injectable uterotonics (such as oxytocin and/or methylergotomine) are available as part of the management of the third stage of ,92 Misoprostol has also not yet been found to be better than oxytocin or ergotamine in wellcontrolled, randomized trials for the treatment of postpartum However, it remains an important option for treating postpartum hemorrhage when other agents are not available or fail. A descriptive study showed that 1000 181。g of rectally administered misoprostol, when given to patients who failed to respond to oxytocin and ergotamine, controlled postpartum hemorrhage within 3 However, further studies, with randomized designs, are needed.ConclusionsMisoprostol has many applications in the practice of obstetrics and gynecology. Offlabel use of approved medications is supported by the FDA as long as it is based on sound medical evidence. Researchers and providers must continue to work to further refine the indications for misoprostol in many areas. However, several indications are already supported by highquality evidence. Given its low cost and ease of use, misoprostol has the potential to improve women’s health worldwide.8 /