Lack of association between unhealthy vaginal pH and bacterial vaginosis positive status

Abstract

Introduction: Bacterial vaginosis (BV) remains highly prevalent worldwide. Although vaginal pH has been suggested to be a good predictor of BV, findings are conflicting. This study investigated the prevalence and risk factors associated with BV and the association between BV and vaginal pH in women from Durban, South Africa.

Methods: This was a cross-sectional study that included 150 pregnant and non-pregnant women. BV was diagnosed using Nugent scoring and vaginal pH was measured using Lovibond^® pH strips. Vaginal pH results were compared with Nugent scores. Statistical analyses were performed in STATA 17.1 using 95% confidence intervals and a significance level of 0.05.

Results: According to Nugent’s criteria, BV prevalence was 29.33%, while an additional 29.33% of the women had intermediate BV. Women aged 31–39 years were more likely to have BV than younger women (odds ratio [OR]: 7.27; 95% CI 1.40- 37.85; p = 0.018). Women with intermediate BV had a 2.4-fold higher likelihood of vaginal dysbiosis (OR: 2.42; 95% CI: 1.07-5.45; p = 0.033). Significant associations were observed between BV status and the presence of BVAB-1 (p = 0.016), BVAB-2 (p = 0.009), BVAB-3 (p = 0.048), Atopobium vaginae (p = 0.029), and Sneathia sanguinegens (p < 0.001). However, vaginal pH was not significantly associated with the prevalence of BV-associated microorganisms (p > 0.05).

Conclusions: BV was common among women in Durban, South Africa; however, vaginal pH was not associated with BV or BV-associated bacteria, indicating that it was a poor predictor of BV in this population.