[Vulvar plethysmographic findings in transsexual women]

Transsexualism is a complicated diagnostic category. From the differential diagnostic aspect it is necessary, among others, to rule out homosexuality. The objective of the present work was to express objectively vulvo-plethysmographic reactions in transsexual women and to assess whether (or how) these reactions differ from findings in women with a homosexual orientation and to evaluate subsequently possibilities of vulvo-plethysmography in the differential diagnosis of homosexuality and transsexualism.

Using an electro-capacitance vulvo-plethysmographic apparatus (designed by Figar et al.), 25 women (mean age 27.6 years, range 18-39 years) with an inverse sexual orientation--transsexuals--were examined. The results were compared with a group of 50 women, matched for age, who reported a homosexual orientation. On evaluation of the total number of recorded positive reactions to heterosexual and homosexual categories of exposed erotic stimuli the difference between the two groups on projection of 3 from 4 categories of these stimuli was highly significant (p < 0.001, chi 2 test). The differences were revealed in particular when evaluating preferences of pictures of sexual activities of partners. While in homosexually oriented women, as expected, preference of homosexual activities was recorded (74%) or a not clear-cut differentiation of these stimuli (26%), in 88% of transsexual women there was a more or less markedly expressed preference of heterosexual activities.

Significant differences were found in results of vulvo-plethysmographic examinations of transsexual and homosexual women. This confirmed the expedience of using electro-capacitance vulvo-plethysmography for the differential diagnosis of homosexual and transsexual women.