Objective: To determine whether outpatient use of timed-release dinoprostone vaginal inserts is a safe and effective option for induction of labour in appropriate low-risk populations.
Methods: We performed a retrospective cohort study of inpatient and outpatient inductions of labour at a level II care hospital between 1998 and 2006. We included women undergoing induction of labour by the use of a dinoprostone vaginal insert, and excluded women with a gestational age of <37 weeks, previous Caesarean section, multiple gestation, or preadmission intrauterine fetal demise. The outcomes examined were other methods of induction used, method and time of delivery, and fetal outcome defined by Apgar scores, and admissions to the neonatal intensive care unit (NICU).
Results: The cohorts included 776 inpatients and 567 outpatients. The outpatient cohort had more post term gestations as the indication for induction (65.43% vs. 30.93%), while the inpatient group was more likely to have indications of premature rupture of membranes (18.94% vs. 6.17%) and gestational hypertension (18.04% vs. 7.05%). Outpatients had significantly higher use of epidural analgesia and oxytocin. Inpatients were more likely to deliver vaginally within 24 hours (OR 2.16; 95% CI 1.57 to 2.97) and also to have a Caesarean section (OR 1.50, 95% CI 1.14 to 1.98). None of the women in the outpatient group had serious complications as an outpatient, and there were no significant differences in fetal outcomes as measured by admission to NICU and Apgar score at 5 minutes.
Conclusion: This study supports the use of controlled-release dinoprostone vaginal inserts in the outpatient setting as a safe alternative for women with a low-risk pregnancy undergoing induction of labour.