Observational study of vaginal pH in healthy Portuguese women

To date, few epidemiological data are available regarding vaginal pH in Portugal. Thus, an epidemiological study was conducted to evaluate vaginal pH in healthy Portuguese women, attending a private gynecologist and its relation with women's socio-demographics, sexual activity and clinical characteristics.

This was an observational cross-sectional, multicenter and national study in 990 healthy women older than 18 years recruited from September-December 2007. Data regarding socio-demographics, sexual activity (1-5 score ordinal scale: 5 represent the best scenario), physiological status, concomitant treatment and vaginal symptoms were collected. Vaginal pH was measured through specific test strips.

The study enrolled women with a median age of 37 years (min-max: 18-83 years) and a median BMI of 24 kg/m2; 63.5% of women practiced some physical activity, 84% were employed, 62.6% were of reproductive age, 22.1% in their post-menopausal phase and 10.4% pregnant. Women considered their sexual lives satisfactory. Median vaginal pH was 4.7 (min-max: 3.5-7.4). Vaginal pH showed positive correlation with age (rs=0.283) and BMI (rs=0.180). Employed women presented a lower median vaginal pH than retired or housewives (4.7 versus 5.6 and 5.3). Higher scores for sexual activity regarding interest, satisfaction, frequency and importance presented lower vaginal pH (respectively rs=-0.171, rs=-0.168, rs=-0.133 and rs=-0.158). Use of contraceptives and pregnancy were associated respectively to lower median levels of vaginal pH. Concomitant treatments and presence of vaginal symptoms were associated with higher median levels of vaginal pH.

Vaginal pH increases with age, BMI, sexual intercourse without barrier contraception, dryness and irritation symptoms and decreases with physical activity, professional activity and hormone replacement therapy.