Iris de Nie

135 GENERAL DISCUSSION AND FUTURE PERSPECTIVES 9 having a total motile sperm count below 5 million. In addition, tucking was performed by 1 out of 4 trans women. In those with a tucking frequency of more than 8 times a month an association with low total motile sperm count was found, which was independent of demographic factors, lifestyle factors and medical history. Although it is recommended to pursue fertility preservation before initiation of GAHT, not for everybody fertility preservation is available prior to the start of gender-affirming treatment. Besides, some trans women choose to keep the male gonads and discontinue gender-affirming medication when an active desire for children emerges. The use of GAHT negatively impacts spermatogenesis, resulting in a severely impaired semen quality or azoospermia. 72 The aim of the study described in chapter 5, was to determine whether loss of spermatogenesis can be reversed after GAHT is ceased. We included nine trans women, each of whom stopped GAHT for reproductive purposes, and we assessed their subsequent ability to produce sperm. Four participants stopped GAHT to conceive with their current partners; the remaining five wished to bank sperm to conceive in the future. It was found that after cessation of GAHT, serum testosterone levels returned to within the male reference range and in all nine individuals viable spermatozoa were found (3-27 months after cessation of GAHT). Three of the four trans women who stopped GAHT to naturally conceive with their current partners successfully did so after 4, 20 and 40 months. These results strongly suggest that the negative impact of GAHT on spermatogenesis can be reversed and may create an opportunity for those who develop a desire for children while already using GAHT. However, it may be difficult to predict how much time is needed for complete recovery of spermatogenesis since in some cases it took many months, during which time testosterone levels increased and are likely to have had negative physical and psychological consequences. Therefore, cessation of GAHT for reproductive purposes is not a feasible option for all trans women. It maybe especiallydifficult for trans womenwho initiatedmedical treatment in earlypuberty, as for them cessation of treatment is accompanied by irreversible and often unwanted physical changes such as a lowering of the voice and facial hair growth. Severe genital dysphoria may pose another barrier for fertility preservation, since semen cryopreservation requires masturbation which is non-negotiable for some young trans women. 54 In the study described in chapter 6 , we assessed if there may still be options for fertility preservation in testicular tissue obtained during GAS, for those who are otherwise unable to have biological children. Outcome was compared between six subgroups, based on Tanner stage/age at start of medical treatment of cessation/continuation of GAHT prior to GAS. It was found that in a small percentage of trans women who initiated medical treatment in Tanner stage 4 or higher, spermatozoa could have been harvested from the orchiectomy specimen at time of GAS. In addition, the vast majority ( > 85%) of trans women in our cohort could still opt for cryopreservation of testicular tissue harboring spermatogonial stem cells. We found that initiation of medical treatment in early-pubertal adolescents (Tanner stage 2-3) limits the ability to retrieve mature spermatozoa that can directly be used for assisted reproductive techniques, since in these orchiectomy specimens only immature germ cells were present. Lastly, we observed that testicular histology and spermatogenesis seemed more negatively