Misoprostol for labor induction: an alternative to dinoprostone? A retrospective observational study

Misoprostol and dinoprostone are established agents for labor induction. Since the introduction of standardized dosing regimens of misoprostol, few studies have evaluated its clinical use. The primary objective was to assess the implementation of a misoprostol-based induction protocol and its safety and effectiveness in routine obstetric care. Secondary objectives included comparing induction-to-delivery time between misoprostol and dinoprostone, evaluating the induction-to-labor interval, need for a second method, and obstetric/neonatal outcomes.

We conducted a retrospective observational study from September 2021 to December 2024. Inclusion criteria were singleton term pregnancies undergoing labor induction with either misoprostol (Group 1) or dinoprostone (Group 2) and a Bishop score < 7.

528 patients were included in Group 1 and 345 in Group 2. A robust double analysis was applied to balance age, gestational age, Bishop score, and parity, aiming to mitigate the potential influence of baseline differences between the groups. No significant differences were observed in induction-to-delivery time (p = 0.710) or time to active labor (p = 0.652). However, Group 1 showed a significantly higher vaginal delivery rate (OR = 1.38; 95% CI: 1.10-1.73; p = 0.004) and a lower risk of postpartum hemorrhage (OR = 0.58; 95% CI: 0.46-0.73; p < 0.001).

The standardized oral misoprostol protocol proved safe and effective for labor induction in patients with an unfavorable cervix. Compared with vaginal dinoprostone, misoprostol showed similar neonatal outcomes and maternal advantages, including higher vaginal delivery rates and reduced postpartum hemorrhage, supporting its use in routine obstetric practice.