The impact of vaginal pH on induction of labour outcomes: a meta-analysis of observational studies

Abstract

The present meta-analysis evaluates the impact of an acidic vaginal pH on the progress of labour induction with dinoprostone and misoprostol. We searched Medline, Scopus, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL, Clinicaltrials.gov and Google Scholar databases for relevant studies. Meta-analysis was performed with Rstudio using the meta function and trial sequential analysis was used to evaluate the adequacy of sample size. Nine studies were retrieved that involved 809 patients. An acidic vaginal pH did not influence the efficacy of misoprostol or dinoprostone in terms of accomplishing a successful vaginal delivery (OR 0.62, 95% CI 0.29, 1.30). The interval to delivery was unaffected by the acidity of vaginal pH (Mean Difference 4.18 h, 95% CI −2.09, 10.45). In conclusion, vaginal pH does not seem to affect the potency of vaginally administered prostaglandins; therefore, moistening of vaginal tables with acetic acid does not seem reasonable until further evidence becomes available.

Keywords:

• Vaginal pH
• dinoprostone
• misoprostol
• acetic acid
• meta-analysis

Author contributions

VP and KP performed the literature search, VP, KP, IB and MP tabulated data, performed quality assessment and wrote the manuscript. VP and GD conceived the idea and wrote the manuscript. AR and AP tabulated the data and wrote the manuscript. GD and AR contributed to the quality assessment and critically revised the manuscript.

Ethical approval

The present systematic review is based on outcomes already published from previous trials in the field. The study is based on aggregated patient data and no IRB approval was required.

Disclosure statement

No potential conflict of interest was reported by the author(s).