Background and Objectives:
To determine if there are racial differences in vaginal pH that could account for the increased prevalence of trichomoniasis among sexually active black women.
We measured the pH of vaginal secretions in a group of 273 sexually active, adolescent females without evidence of lower genital tract infection or cervical inflammation.
Univariate analyses revealed that seven factors (black race, current alcohol use, nonsmoking status, gravidity, parity, and younger chronologic and gynecologic age) were significantly associated with a more alkaline vaginal pH. After a step-wise multiple regression analysis only three factors (black race, current alcohol use and parity) remained significantly related to vaginal pH, with the strongest association for black race (mean + standard deviation [SD] for vaginal pH among black adolescents 5.3 + 0.7 compared to 4.7 + 0.6 for other adolescents; P < .0001).
The pathophysiologic mechanisms that underlie the racial differences we identified in vaginal pH remain to be elucidated. Nevertheless, we speculate that race-related variations in the pH of normal vaginal secretions may decrease the resistance of black adolescents, one of the highest-risk obstetric population in this country, to common vaginal infections, such as trichomoniasis and bacterial vaginosis.
© Copyright 1994 American Sexually Transmitted Diseases Association