Oral Misoprostol for Induction of Labour in Term PROM: A Systematic Review

Abstract

Objective: To assess the efficacy of oral misoprostol for induction of labour (IOL) in the context of term pre-labour rupture of membranes (TPROM), and to assess pregnancy outcomes following the administration of oral misoprostol.

Data sources: A systematic literature search was performed using Ovid Medline, Embase, PubMed, and the Cochrane Database of Systematic Reviews.

Study selection: Eligible studies were quasi-experimental trials or randomized controlled trials involving the use of oral misoprostol in singleton cephalic term pregnancies with confirmed rupture of membranes and no spontaneous labour at the time of membranes rupture, in mothers with no contraindications to vaginal delivery. Studies were excluded if they utilized vaginal misoprostol, excluded primigravid participants, or if the full text of the article was not accessible in English.

Data extraction: Data were extracted by two reviewers using a standardized data extraction form. Study quality was assessed using the modified Jadad score.

Data synthesis: Twelve randomized controlled trials that included 1489 singleton pregnancies were included. Doses of oral misoprostol ranged from 20 to 200 μg. The incidence of vaginal birth ranged from 73.0%-95.0% in the oral misoprostol group compared with 52.4%-94% in the control group. Hyperstimulation was infrequent, ranging from 0% to 13.8% in the oral misoprostol group compared with 0%-24% in the control group. Two trials, involving a total of 144 women that compared 50 μg of oral misoprostol every 4 hours versus expectant management followed by PGE₂ gel showed a higher incidence of vaginal birth with misoprostol (pooled risk ratio 1.33, 95% confidence interval 1.10-1.61).

Conclusion: Oral misoprostol appears to be a safe and effective for IOL in TPROM. However, the varying administration, dose, and frequency reported in the literature highlights the need to develop a standardized protocol for use in Canadian obstetrical practice.

Keywords: administration, oral; fetal membranes, premature rupture; labor, induced; misoprostol; pregnancy, third trimester.