Dinoprostone Vaginal Insert for Induction of Labor in Women with Low-Risk Pregnancies: A Prospective Study

Background: Induction of labor (IOL) is a technique to establish vaginal delivery when the risks for continuing the pregnancy for mother or baby are higher than the risks of delivery. It is usually performed in high-risk pregnancies, but can also be beneficial in low-risk populations, as shown in the ARRIVE trial. Objective: To evaluate the effectiveness and safety of slow-release vaginal dinoprostone (prostaglandin E2 10 mg) for labor induction in women with low-risk pregnancies. Methods: A prospective study was performed at Hanoi Obstetrics and Gynecology Hospital, Vietnam. We recruited women with low-risk pregnancies from 39 weeks + 0 days to 40 weeks + 6 days of gestation and an unfavorable cervix. Women who participated received 10 mg intravaginal slow-release dinoprostone (Propess) for induction of labor. Labor, deliveries, and post-partum management were performed according to the local protocol. Results: From September 2020 to March 2021, 102 low-risk women were eligible to participate in the study. Among these women, 67.6% had vaginal deliveries, 6.9% had postpartum bleeding, and 3.9% experienced tachysystole. All newborns were healthy, with good APGAR scores. None of the women needed respiratory support or intensive care unit admission. All other maternal or fetal complications were explored. The rate of cesarean section was 3.8 higher in nulliparous than multiparous women and 2.2 times higher in women who did not receive epidural analgesia than in those who did. The risk of cesarean section increased if the time between labor induction and active labor was greater than 12.5 hours. Conclusion: Slow-release dinoprostone insert is safe and effective for the induction of labor in low-risk pregnant women. The risk of cesarean section was elevated in nulliparous patients and those who did not receive epidural analgesia during labor. As the time from labor induction to active labor increased, the risk of cesarean section increased.