Histological study on the influence of puberty suppression and hormonal treatment on developing germ cells in transgender women

Abstract

STUDY QUESTION Can transgender women cryopreserve germ cells obtained from their orchiectomy specimen for fertility preservation, after having used puberty suppression and/or hormonal treatment? SUMMARY ANSWER In the vast majority of transgender women, there were still immature germ cells present in the orchiectomy specimen, and in 4.7% of transgender women—who all initiated medical treatment in Tanner stage 4 or higher—mature spermatozoa were found, which would enable cryopreservation of spermatozoa or testicular tissue after having used puberty suppression and/or hormonal treatment. WHAT IS KNOWN ALREADY Gender affirming treatment (i.e. puberty suppression, hormonal treatment, and subsequent orchiectomy) impairs reproductive function in transgender women. Although semen cryopreservation is generally offered during the transition process, this option is not feasible for all transgender women (e.g. due to incomplete spermatogenesis when initiating treatment in early puberty, in case of inability to masturbate, or when temporary cessation of hormonal treatment is too disruptive). Harvesting mature spermatozoa, or testicular tissue harboring immature germ cells, from orchiectomy specimens obtained during genital gender-affirming surgery (gGAS) might give this group a chance of having biological children later in life. Previous studies on spermatogenesis in orchiectomy specimens showed conflicting results, ranging from complete absence of germ cells to full spermatogenesis, and did not involve transgender women who initiated medical treatment in early- or late puberty. STUDY DESIGN, SIZE, DURATION Histological and immunohistochemical analyses were performed on orchiectomy specimens from 214 transgender women who underwent gGAS between 2006 and 2018. Six subgroups were identified, depending on pubertal stage at initiation of medical treatment (Tanner stage 2-3, Tanner stage 4-5, adult), and whether hormonal treatment was continued or temporarily stopped prior to gGAS in each of these groups. PARTICIPANTS/MATERIALS, SETTING, METHODS All transgender women used a combination of estrogens and testosterone suppressing therapy. Orchiectomy specimen sections were stained with Mayer’s hematoxylin and eosin and histologically analyzed to assess the Johnsen score and the ratio of most advanced germ cell types in at least 50 seminiferous tubular cross-sections. Subsequently, immunohistochemistry was used to validate these findings using spermatogonia, spermatocytes or spermatids markers (MAGE-A3/A4, γH2AX, Acrosin, respectively). Possibilities for fertility preservation were defined as: preservation of spermatozoa, preservation of spermatogonial stem cells or no possibilities (in case no germ cells were found). Outcomes were compared between subgroups and logistic regression analyses were used to assess the association between the duration of hormonal treatment and the possibilities for fertility preservation. MAIN RESULTS AND THE ROLE OF CHANCE Mature spermatozoa were encountered in 4.7% of orchiectomy specimens, all from transgender women who had initiated medical treatment in Tanner stage 4 or higher. In 88.3% of the study sample orchiectomy specimens only contained immature germ cells (round spermatids, spermatocytes or spermatogonia, as most advanced germ cell type). In 7.0%, a complete absence of germ cells was observed, all these samples were from transgender women who had initiated medical treatment in adulthood. Cessation of hormonal treatment prior to gGAS did not affect the presence of germ cells or their maturation stage, nor was there an effect of the duration of hormonal treatment prior to gGAS. LIMITATIONS, REASONS FOR CAUTION Since data on serum hormone levels on the day of gGAS were not available, we were unable to verify if the transgender women who were asked to temporarily stop hormonal treatment 4 weeks prior to surgery actually did so, and if people with full spermatogenesis were compliant to treatment. WIDER IMPLICATIONS OF THE FINDINGS There may still be options for fertility preservation in orchiectomy specimens obtained during gGAS since a small percentage of transgender women had full spermatogenesis, which could enable cryopreservation of mature spermatozoa via a testicular sperm extraction procedure. Furthermore, the vast majority still had immature germ cells, which could enable cryopreservation of testicular tissue harboring spermatogonial stem cells. If maturation techniques like in vitro spermatogenesis become available in the future, harvesting germ cells from orchiectomy specimens might be a promising option for those who are otherwise unable to have biological children. STUDY FUNDING/COMPETING INTEREST None. TRIAL REGISTRATION NUMBER N/A.

Germline stem cells in human

“… 387 Transgender women might also cryopreserve their germ cells before hormonal treatment, as a small percentage of transgender women have immature male germ cells. 388 …”

“…387 Transgender women might also cryopreserve their germ cells before hormonal treatment, as a small percentage of transgender women have immature male germ cells. 388 Testis-derived germ cell microinjection into seminiferous tubules of infertile recipients was first reported in mice, and transplanted cells colonized seminiferous tubules and initiated spermatogenesis. 389,390 Germ cell transplantation in interspecies and intraspecies has been applied to zebrafish, rats, dogs, farm animals (goats, sheep, pigs, and cattle), nonhuman primates, and humans, in addition to mice.…”

Spermatogonial Stem Cell-Based Therapies: Taking Preclinical Research to the Next Level

“…Generally, testicular tissues derived from patients with underlying conditions, or undergoing treatments that affect meiosis and/or spermiogenesis, such as hormonal treatments for gender dysphoria ( 11 , 12 ) or infectious diseases ( 13 ), could be used under the assumption that spermatogonial function is not affected. It is known that the vast majority of testicular tissue obtained during orchiectomy in transwomen contains spermatogonia ( 14 ). However, to our knowledge, the effects of these conditions on SSCs have not been systematically studied.…”

Kontrazeption, Fertilität und Fertilitätsprotektion bei Transpersonen unter geschlechtsangleichender Hormontherapie

“…Ergebnisse Bis zu 87 % der TGD-Männer verwenden Verhütungsmittel 1 2 3 , wobei die Induktion einer Amenorrhoe ein Hauptanliegen ist 4 . Die meisten der verfügbaren Studien zeigten keine Beeinträchtigung der ovariellen Reserve durch die GAHT 5 6 7 8 9 , aber eine deutliche Wirkung auf die Spermatogenese 10 11 12 13 14 15 16 17 18 19 20 21 22 . Selbst nach Beginn der GAHT unterschied sich die Anzahl der nach ovarieller Stimulation gewonnenen Eizellen bei Transgender-Männern nicht von der altersentsprechender Frauen 23 24 25 26 27 .…”