Observational Study of Neonatal Safety for Outpatient Labour Induction Priming with Dinoprostone Vaginal Insert

Objectives: To evaluate the safety of outpatient induction with dinoprostone insert in low-risk labour inductions for premature rupture of membranes or postdates gestation. Methods: This retrospective cohort study compared outpatient labour induction priming with inpatient induction in terms of neonatal safety, mode of delivery, and obstetrical parameters. The sample included all inductions for premature rupture of membranes or postdate gestation. The analysis used logistic regression. The statistical power of the sample was 80% to detect a difference of 5.6% for the composite neonatal safety outcome (5-minute Apgar score < 7 and NICU admission for > 12 hours or transfer to a level III nursery). Results: Compared with the inpatient cohort (n = 568), the outpatient cohort (n = 611) included more postdate gestations (93% vs. 67%) with less cervical dilatation (0.5 cm vs. 1.0 cm) and larger infants (3705 g vs. 3551 g). There were no differences in measures of neonatal safety or mode of delivery. The outpatient cohort required more dinoprostone inserts (1.59 vs. 1.23) and were less likely to deliver within 24 hours (OR 0.24, 95% CI 0.17 to 0.34) but were also less likely to deliver by CS (OR 0.71, 95% CI 0.54 to 0.95), after adjusting for obstetrical parameters. Conclusion: An outpatient model of labour induction using dinoprostone inserts is feasible and safe.