Comparison of Synthetic Osmotic Dilators and Vaginal Misoprostol for Cervical Preparation Prior to Hysteroscopy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

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Abstract

OBJECTIVE: Hysteroscopy is a widely used minimally invasive procedure for the diagnosis and treatment of intrauterine pathologies. Adequate cervical preparation is essential for safe and effective hysteroscope insertion. This systematic review and meta-analysis aimed to compare the efficacy and safety of synthetic osmotic dilators and vaginal misoprostol for cervical ripening prior to hysteroscopy. DATA SOURCES: A comprehensive literature search was conducted across PubMed/MEDLINE, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials, covering all records from database inception through October 2025. METHODS OF STUDY SELECTION: Randomized controlled trials (RCTs) comparing synthetic osmotic dilators versus vaginal misoprostol for cervical preparation before hysteroscopy were included. The primary outcome was the degree of cervical dilatation achieved. Secondary outcomes included procedural pain, incidence of difficult cervical dilatation, systemic adverse events, and procedural complications. Statistical pooling was performed using Review Manager (RevMan) software. TABULATION, INTEGRATION, AND RESULTS: Four RCTs comprising 348 participants were included. Synthetic osmotic dilators demonstrated significantly greater cervical dilatation and lower procedural pain scores during hysteroscopy compared to vaginal misoprostol (p < 0.001). The incidence of difficult cervical dilatation was lower in the osmotic dilator group (15%) compared to the misoprostol group (42%). Additionally, nausea, vomiting, abdominal pain, and hysteroscopic complications were all significantly less frequent in the osmotic dilator group (p < 0.001). CONCLUSION: Although synthetic osmotic dilators appear to be a more effective and better-tolerated option than vaginal misoprostol for cervical ripening prior to hysteroscopy, this evidence is drawn from a limited number of small trials and should be considered preliminary. Larger multicenter randomized trials with standardized outcome definitions are needed before these findings can guide clinical practice.

Abstract as published, via PubMed.