Epidemiologic determinants of vaginal pH

Am J Obstet Gynecol. 1999 May;180(5):1060-6. doi: 10.1016/s0002-9378(99)70595-8.


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 Province in Costa Rica women were categorized into 2 groups, those with vaginal 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 elevated 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 responsible for an additional 1.7-fold increase in the odds of having an elevated pH (odds ratio 1.7, 95% confidence interval 1.4-2.0). Human papillomavirus infection and cervical intraepithelial neoplasia were not associated with changes in pH.

Conclusions: Our data indicate that vaginal pH is strongly related to age and 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-grade intraepithelial neoplasia among women infected with human papillomavirus.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Aging*
  • Cervical Intraepithelial Neoplasia / metabolism
  • Costa Rica
  • Female
  • Humans
  • Hydrogen-Ion Concentration
  • Menopause*
  • Menstruation
  • Middle Aged
  • Papillomaviridae
  • Papillomavirus Infections / metabolism
  • Reference Values
  • Tumor Virus Infections / metabolism
  • Vagina / chemistry*