Epidemiologic determinants of vaginal pH

OBJECTIVES: This study was undertaken to evaluate the relationship between vaginal pH and factors related to cervical cancer. STUDY DESIGN: In a population-based sample of 9161 women from Guanacaste Pr ovince in Costa Pica women were categorized into 2 groups, those with vagin al pH in the reference range (4.0-4.5) and those with elevated vaginal pH ( 5.0-5.5). Odds ratios were used to estimate the relationship between elevat ed pH and its potential determinants. RESULTS: Aging was strongly associated with increasing vaginal pH, starting at around 45 years of age and continuing into old age. Menopause was respo nsible for an additional 1.7-fold increase in the odds of having an elevate d pH (odds ratio 1.7, 95% confidence interval 1.4-2.0). Human papillomaviru s infection and cervical intraepithelial neoplasia were not associated with changes in pH. CONCLUSIONS: Our data indicate that vaginal pH is strongly related to age a nd to menopausal status and thus could be a marker of age-related hormonal changes. Elevated pH does not appear to be associated with risk of high-gra de intraepithelial neoplasia among women infected with human papillomavirus .