# The Safety of Two Different Oral Misoprostol Dosing Strategies for Labor Preinduction at Term: A Single-Center Retrospective Cohort Study

## TL;DR

This study compared two oral misoprostol dosing strategies for preinducing labor and found both to be equally safe and effective for term pregnancies.

## Contribution

The study provides evidence on the safety and effectiveness of two oral misoprostol regimens for labor preinduction.

## Key findings

- Both dosing regimens showed similar maternal and neonatal safety outcomes.
- The need for a Foley catheter was initially higher in the 50 µg group but not significant after adjusting for PROM.
- Cesarean section rates and neonatal outcomes were comparable between the two groups.

## Abstract

Background/Objectives: Preinduction of labor is commonly performed in women with unfavorable cervical conditions at term. Oral misoprostol is increasingly used due to its ease of administration and effectiveness; however, optimal dosing regimens remain under investigation. This study aimed to evaluate the safety and effectiveness of two oral misoprostol regimens (25 µg every 2 h versus 50 µg every 4 h) for preinduction of labor in term pregnancies. Methods: This single-center retrospective cohort study included 270 women with singleton term pregnancies who underwent oral misoprostol preinduction. Women received either 25 µg every 2 h (n = 60) or 50 µg every 4 h (n = 210) according to routine clinical protocols. Data were collected from electronic medical records and included demographic and obstetric characteristics, labor course, need for additional interventions (e.g., Foley catheter), and neonatal outcomes. The primary outcome was a composite maternal and neonatal safety endpoint. Secondary outcomes included mode of delivery, need for Foley catheter use, and time to delivery. Results: Both regimens were effective in facilitating labor progression. In crude analysis, the need for additional cervical ripening with a Foley catheter was higher in the 50 µg group compared with the 25 µg group (37.1% vs. 21.7%, p = 0.037); however, after stratification by prelabor rupture of membranes (PROM), this difference was no longer statistically significant (p = 0.39). Cesarean section rates did not differ significantly between groups (29.0% vs. 20.0%, p = 0.22). The time from the last misoprostol dose to delivery was shorter in the 50 µg group, but the difference was not statistically significant (p = 0.17). Neonatal outcomes, including birthweight, Apgar scores, and umbilical cord blood gas parameters, were comparable between groups. No severe maternal or neonatal adverse events were recorded. Conclusions: In this single-center retrospective cohort study, the 25 μg every 2 h and 50 μg every 4 h oral misoprostol regimens were associated with comparable obstetric and neonatal outcomes within the analyzed parameters. No significant differences in recorded maternal or neonatal safety outcomes were observed. Selection of the dosing regimen should take into account individual clinical factors, including parity, cervical status, and membrane status.