Induction of labor with repeated prostaglandin administration after failure of dinoprostone vaginal insert: a retrospective study comparing dinoprostone and misoprostol

Background: Induction of labor in women with unfavorable cervix can be started with cervical ripening by dinoprostone vaginal insert. In cases of unsuccessful response, management is unclear: a possible option is a repeated induction with prostaglandins. The aim of this study was to assess the results of a second induction by either dinoprostone or misoprostol, comparing those treatments. Methods: A retrospective analysis was carried out on a cohort of 109 women with unsuccesful response to a first attempt of induction with dinoprostone vaginal insert, who required a second stimulation by either dinoprostone vaginal gel (56 patients) or oral misoprostol (53 patients). The outcomes assessed where the rates of active labor and vaginal delivery, and secondarily maternal and perinatal adverse events. Results: Overall 70.6% of patients reached active labor and 62.4% had a vaginal delivery; the efficacy of the double induction was similar for dinoprostone vaginal gel and oral misoprostol, with active labor in 69.6% and 71.7% (P=0.83), and vaginal delivery in 62.5% and 62.3% of patients (P=0.99) respectively. The incidence of adverse events was low, with no perinatal complications and similar rates of maternal complications, notably major post-partum hemorrhage in 1.8% and 3.8% of patients (P=0.61) for dinoprostone and misoprostol respectively. Conclusions: Dinoprostone vaginal gel and oral misoprostol as a second cycle of induction appear to be both effective in achieving active labor and vaginal delivery after failure of dinoprostone vaginal insert, without a significant rate of adverse events.