Measurement of vaginal and minor labial oxygen tension for the evaluation of female sexual function

Female sexual dysfunction is a new, rapidly expanding area of sexual medicine. Female sexual arousal disorder may, in part, be due to decreased pelvic blood flow. Therefore, we developed a simple noninvasive reproducible technique to measure vaginal and minor labial blood flow.

The study included 12 healthy young women able to have orgasm through self-stimulation. Observations at orgasm were recorded in the 12 subjects after self-stimulation. Measurements were obtained intravaginally and on the minor labia using a modified Clark oxygen electrode to obtain partial oxygen pressure (pO(2)).

Mean basal vaginal value was 3.8 +/- 0.9 mm Hg and mean basal pO(2) on the minor labia was 18.3 +/- 3.7 mm. Hg. As soon as self-stimulation was initiated an increase in oxygen tension occurred and continued during sexual stimulation. Just before orgasm a further increase was noted with peak values measured immediately after the orgasm began (pO(2) 28.6 +/- 3.1 mm Hg intravaginally and 47.3 +/- 4.1 labial). Labial pO(2) measurement decreased relatively rapidly soon after orgasm. The time to return to basal vaginal values after orgasm varied from 20 to 30 minutes.

Previously, changes in female sexual arousal responses have been difficult to evaluate and quantify clinically. We developed a simple noninvasive reproducible technique to measure vaginal and minor labial blood flow. Age based and cycle dependent normograms now can be produced for vaginal and labial blood flow using this method.