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

Purpose: Female sexual dysfunction is a new, rapidly expanding area of sexu al medicine. Female sexual arousal disorder may, in part, be due to decreas ed pelvic blood flow. Therefore, we developed a simple noninvasive reproduc ible technique to measure vaginal and minor labial blood flow. Materials and Methods: The study included 12 healthy young women able to ha ve orgasm through self-stimulation. Observations at orgasm were recorded in the 12 subjects after self-stimulation. Measurements were obtained intrava ginally and on the minor labia using a modified Clark oxygen electrode to o btain partial oxygen pressure (pO(2)). Results: 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 w as initiated an increase in oxygen tension occurred and continued during se xual 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 decrea sed relatively rapidly soon after orgasm. The time to return to basal vagin al values after orgasm varied from 20 to 30 minutes. Conclusions: Previously, changes in female sexual arousal responses have be en difficult to evaluate and quantify clinically. We developed a simple non invasive reproducible technique to measure vaginal and minor labial blood f low. Age based and cycle dependent normograms now can be produced for vagin al and labial blood flow using this method.