Pathophysiology of Vaginal Erosions in Women Using Pessary: A Pilot Study Examining Vaginal Microbiota

Many women with pelvic organ prolapse opt for a pessary, and some of these women develop erosions of the vaginal mucosa. Ongoing erosions might lead to the discontinuation of this otherwise effective, non-invasive, and inexpensive treatment. The objectives of this study were to investigate the differences in vaginal pH and variations of the vaginal microbiota among pessary and non-pessary users.

For this descriptive observational study, 30 women, followed in our urogynecology clinic, were recruited to form 3 equal groups: 2 groups of women using a pessary (with and without erosions) and 1 control group of women not using a pessary. Vaginal pH was measured distally and next to the erosion. Vaginal swabs were used to investigate the vaginal microbiota by sequencing the V4 region of the 16S ribosomal RNA gene and analyzing the data with Qiime2. Descriptive statistics were reported using the median values. Vaginal pH comparisons between groups were made using a Kruskal-Wallis test with Dunn's correction for multiple comparisons.

The pH of the vagina was more alkaline in women with erosions compared with women in the other 2 groups (P < 0.01). Also, the pH of the distal vagina was not different from the pH next to the erosion (P = 0.25). Patients with erosions displayed significant differences in their vaginal microbiota, which contained a much greater bacterial diversity with an increase in gram-negative bacteria (e.g., Bacteroidetes, Actinobacteria) and a decrease in lactobacilli.

In our study, women with vaginal erosions had significantly higher vaginal pH and more complex vaginal microbiota than women in the control groups. Treatments focusing on lowering the vaginal pH and/or re-establishing the vaginal microbiota should be considered.