Objective: Sexual orientation in males and females is considered to be determined in early life and to be virtually unchangeable in the course of adulthood. In contrast some transsexuals report a change in their sexual orientation most overt following sex reassignment procedures. The reason for this phenomenon is unknown.
Methods: We asked 106 transsexual (66 MtF and 40 FtM) patients from our endocrine outpatient clinic to complete a questionnaire, retrospectively evaluating the history of their gender transition phase. A special focus was sexual orientation and prevalence and recalled time point of changes in their sexual orientation.
Results: FtM were most frequently heterosexual, according to their gender identity, while MtF more often reported to be homosexual (72.5 vs 29% and 33.8 vs 7.5% respectively; P<0.001). MtF reported change in sexual orientation in total in 32.8% of cases in contrast to FtM with only 17.5% (P=0.067). 6 MtF (21.4%) reported change in sexual orientation without any sex reassignment surgery in their history in contrast to only 2 FtM (12.5%). Of those who had undergone sex reassignment surgery, most but not all subjects had experienced changes in their sexual orientation following the surgical procedure (13 MtF (73.3%), 5 FtM (71%)). While there was no significant difference seen in terms of time interval between date of introduction of cross-sex hormone treatment and changes in sexual orientation, MtF experienced changes in sexual orientation more quickly after sex reassignment surgery in contrast to FtM (13.8 vs 1.75 years P<0.05).
Conclusion: In contrast to earlier reports, we showed that changes in sexual orientation do not solely occur in the context of sex reassignment surgery. Furthermore, there are clear differences between MtF and FtM, who especially reported a significantly longer interval from sex reassignment surgery to the change in sexual orientation.