Safety of the use of dinoprostone gel and vaginal insert for induction of labor: A multicenter retrospective cohort study

Objective: To assess adverse obstetric and neonatal outcomes associated with the use of dinoprostone for induction of labor, with particular attention on categories for which caution is recommended by the Italian Medicines Agency and the European Medicine Agency. Methods: A retrospective multicenter observational study was conducted on a population of 1687 patients undergoing induction of labor with vaginal dinoprostone (gel or insert) between August 2019 and June 2022. Patients were subdivided based on maternal age, gestational age, and obstetric disorders. Data regarding the mode of delivery, the incidence of tachysystole, and the obstetric and perinatal outcomes were collected. Results: The main adverse event associated with the use of dinoprostone was tachysystole. However, tachysystole was not associated with an increased risk of cesarean section (CS), neonatal intensive care (NICU) admission, low 1-min Apgar, or umbilical cord acidosis. Maternal age greater than 35 years, gestational age greater than 40 weeks, and obstetric disorders were not associated with an increased rate of tachysystole, NICU admission, low 1- and 5-min Apgar scores, and cord acidosis. The only associated adverse outcomes in those categories were postpartum hemorrhage with age greater than 35 years and tachysystole with gestational diabetes mellitus and hypertensive disorders. Not a single case of severe outcome (disseminated intravascular coagulation, uterine rupture, maternal and fetal death) was reported in the cohort. Conclusion: Providing there is adequate maternal and fetal surveillance, in an inpatient setting, dinoprostone could be safely administered for the induction of labor and considered appropriate in high-risk pregnancies. Tachysystole can be self-identified by the patient and effectively managed. Regardless of maternal or gestational age, dinoprostone can safely be administered for induction of labor in high-risk pregnancies; tachysystole is the main adverse outcome with its use.