Bacterial Vaginosis Incidence Following a Single Hyperosmolal Vaginal Lubricant Exposure: A Comparison of Two Observational Cohorts.

Background: Hyperosmolal lubricants may negatively affect the vaginal microenvironment, increasing the risk for bacterial vaginosis (BV). We compared the incidence of Amsel-defined BV in reproductive-age women exposed to hyperosmolal lubricant during transvaginal ultrasound to those without recent lubricant exposure.

Methods: We analyzed 2 observational cohorts over 10 weeks: 58 lubricant-exposed women from the Gynecology and Lubricants Effects study and 59 lubricant-unexposed women from a University of Alabama Birmingham cohort linked to the University of Maryland Human Microbiome Project. Bacterial vaginosis was diagnosed using Amsel criteria at baseline, mid-study (lubricant-exposed, week 2; lubricant-unexposed, week 5), and final visit (week 10), and categorized by symptomatology. Risks for incident BV and Amsel criteria were assessed using modified Poisson regression with robust standard errors. An additional outcome of new-onset/newly symptomatic BV included those with baseline asymptomatic BV. A secondary analysis focused on Black participants (N = 73) due to an observed higher BV incidence.

Results: Baseline demographics and behaviors were similar between the cohorts. Among all participants, lubricant was not associated with new-onset BV (adjusted relative risk [aRR], 1.32; 95% confidence interval [CI], 0.58-3.01). Eighty-eight percent (23/26) of all new-onset/newly symptomatic BV cases occurred in Black participants. Among Black participants, exposure to lubricant doubled the risk of developing new-onset BV (aRR, 2.18; 95% CI, 1.16-4.11) and new-onset/newly symptomatic BV (aRR, 1.91; 95% CI, 1.04-3.51), and increased the risk for new-onset clue cells (aRR, 2.18; 95% CI, 1.17-4.06) versus no lubricant exposure.

Conclusion: Hyperosmolal lubricants was associated with BV incidence in Black women. Factors contributing to this elevated risk require further research.