Clinical impacts of botulinum toxin type A injections for provoked vestibulodynia: insights from randomized controlled trials.

[BACKGROUND] Provoked vestibulodynia (PVD) is a chronic vulvar pain condition often associated with pelvic floor muscle hypertonicity. Botulinum neurotoxin type A (BoNT-A), a neuromuscular transmission blocker, has been proposed as a potential treatment to alleviate PVD-related symptoms. However, its clinical efficacy and safety remain uncertain.

[OBJECTIVE] To systematically assess the efficacy and safety of BoNT-A injections in women with PVD through a meta-analysis of randomized controlled trials (RCTs).

[METHODS] We conducted a systematic review and meta-analysis following PRISMA guidelines. A comprehensive search of MEDLINE, Embase, and Cochrane Library databases was performed up to March 2025 to identify RCTs comparing BoNT-A injections with placebo. Pooled effect sizes were calculated using standardized mean differences (SMDs) or weighted mean differences (WMDs), with 95% confidence intervals (CIs), based on fixed- or random-effects models depending on heterogeneity.

[RESULTS] Four RCTs involving 244 women (BoNT-A: n = 143; placebo: n = 101) were included. BoNT-A treatment did not significantly reduce pain (SMD = - 0.13; 95% CI: - 0.39 to 0.13; p = 0.80), nor did it improve sexual function (WMD = - 0.09 points on the FSFI; 95% CI: - 6.42 to 6.25; p = 0.98) or sexual distress (WMD = 0.15 points on the FSDS; 95% CI: - 9.35 to 9.64; p = 0.98). No serious adverse events were reported, and minor injection-site discomfort was the most common adverse effect.

[CONCLUSIONS] While BoNT-A appears to be well tolerated, current evidence from randomized trials does not consistently support its efficacy in relieving pain or improving sexual function in women with PVD. The limited number of studies and variability in intervention protocols warrant cautious interpretation of these findings.

[TRIAL REGISTRATION] CRD420251024448.