Vaginal physiology in postmenopausal women: pH value, transvaginal electropotential difference, and estimated blood flow.

Basal vaginal physiologic study, including pH values in various locations, transvaginal electropotential difference, and blood flow estimation, was done twice in a group of 34 untreated postmenopausal women. Plasma hormone levels (gonadotropins and estrogens) and vaginal cytology were also obtained to confirm the estrogen deficiency state. The pH values in the vaginal fornices were significantly lower than those in the middle portion of the vagina. Sexually active women had significantly lower pH values than sexually inactive women. The transvaginal electropotential difference and estimated blood flow values were lower than those of premenopausal women reported in the literature, indicating impaired vaginal transport mechanism and decreased vaginal blood flow. The close approximation of the data obtained in the two measurements one month apart attests the reproducibility of the methods used.