Background: Gender-affirming hormone therapy has been hypothesized to reduce the patient's reproductive potential in transmen, although the exact long-term effects on future fertility are unknown.
Methods: In this prospective cohort study we aimed to evaluate ovaries of 20 transmen by using hormone serum levels, histomorphological analysis and fluorescence activated cells sorting (FACS) analysis - in order to assess the amount of vital cells.
Results: The median total number of follicles per field of view was 39 (IQR 12-122). Of all follicles (n = 1661), the vast majority was primordial (n = 1505, 90.6%), followed by primary (n = 76, 4.6%), abnormal (n = 63, 3.8%) and secondary follicles (n = 17, 1.0%). FACS analysis was available for 13 samples (65.0%) and the median frequency of vital cells was 87.5% (IQR, 77.7-95.4%). Both a higher age (p = 0.032) and a lower BMI (p = 0.003) were significantly associated with a higher frequency of vital cells.
Conclusion: The majority of ovarian cells after long-term androgen treatment were vital in FACS analysis and histomorphological evaluation revealed a normal cortical follicle distribution. These results are currently exploratory, but might be promising for issues on fertility preservation.
Trial registration: The study was approved by the ethics committee of the Medical University of Vienna (EK 2240/2016) and was retrospectively registered in the Current Controlled Trials Register (registration number NCT03649087 , date of registration: 28.08.2018).
Keywords: Fertility; Fluorescence activated cells sorting (FACS); Histomorphology; Transgender; Transmen.