Male fertility preservation and restoration strategies for patients undergoing gonadotoxic therapies†.

Medical treatments for cancers or other conditions can lead to permanent infertility. Infertility is an insidious disease that impacts not only the ability to have a biological child but also the emotional well-being of the infertile individuals, relationships, finances, and overall health. Therefore, all patients should be educated about the effects of their medical treatments on future fertility and about fertility preservation options. The standard fertility preservation option for adolescent and adult men is sperm cryopreservation. Sperms can be frozen and stored for a long period, thawed at a later date, and used to achieve pregnancy with existing assisted reproductive technologies. However, sperm cryopreservation is not applicable for prepubertal patients who do not yet produce sperm. The only fertility preservation option available to prepubertal boys is testicular tissue cryopreservation. Next-generation technologies are being developed to mature those testicular cells or tissues to produce fertilization-competent sperms. When sperm and testicular tissues are not available for fertility preservation, inducing pluripotent stem cells derived from somatic cells, such as blood or skin, may provide an alternative path to produce sperms through a process call in vitro gametogenesis. This review describes standard and experimental options to preserve male fertility as well as the experimental options to produce functional spermatids or sperms from immature cryopreserved testicular tissues or somatic cells.

Unique metabolic phenotype and its transition during maturation of juvenile male germ cells.

Human male reproductive development has a prolonged prepubertal period characterized by juvenile quiescence of germ cells with immature spermatogonial stem cell (SSC) precursors (gonocytes) present in the testis for an extended period of time. The metabolism of gonocytes is not defined. We demonstrate with mitochondrial ultrastructure studies via TEM and IHC and metabolic flux studies with UHPLC-MS that a distinct metabolic transition occurs during the maturation to SSCs. The mitochondrial ultrastructure of prepubertal human spermatogonia is shared with prepubertal pig spermatogonia. The metabolism of early prepubertal porcine spermatogonia (gonocytes) is characterized by the reliance on OXPHOS fuelled by oxidative decarboxylation of pyruvate. Interestingly, at the same time, a high amount of the consumed pyruvate is also reduced and excreted as lactate. With maturation, prepubertal spermatogonia show a metabolic shift with decreased OXHPOS and upregulation of the anaerobic metabolism-associated uncoupling protein 2 (UCP2). This shift is accompanied with stem cell specific promyelocytic leukemia zinc finger protein (PLZF) protein expression and glial cell-derived neurotropic factor (GDNF) pathway activation. Our results demonstrate that gonocytes differently from mature spermatogonia exhibit unique metabolic demands that must be attained to enable their maintenance and growth in vitro.

Cryopreservation of Ovarian Tissue for Pediatric Fertility.

Intensive treatments necessary to treat some childhood malignancies and other conditions, as well as certain anatomic variations, may lead to infertility in adulthood. Until recently, no fertility preservation options for prepubertal females were available. However, ovarian tissue cryopreservation has emerged as a safe and effective option for these children. In the next several years, it is likely that more pediatric patients, their families, and medical teams will pursue an ovarian cryopreservation protocol at their institutions. Patient selection, consenting, and laparoscopic oophorectomy can be done at many centers. Then, the ovarian tissue is initially processed and transported to a specialized center for processing for cryopreservation. The cryopreservation techniques are best performed at appropriately certified centers processing high volumes of reproductive cells/tissues with expert personnel and specialized equipment. This article aims to provide an overview for pediatric biobank professionals who may be called to participate in this or similar protocols.

Fertility Preservation Outcomes in Adolescent and Young Adult Feminizing Transgender Patients.

BACKGROUND: Fertility preservation enables patients undergoing gonadotoxic therapies to retain the potential for biological children and now has broader implications in the care of transgender individuals. Multiple medical societies recommend counseling on fertility preservation before initiating therapy for gender dysphoria; however, outcome data pre- and posttreatment are limited in feminizing transgender adolescents and young adults. METHODS: The University of Pittsburgh Institutional Research Board approved this study. Data were collected retrospectively on transgender patients seeking fertility preservation between 2015 and 2018, including age at initial consultation and semen analysis parameters. RESULTS: Eleven feminizing transgender patients accepted a referral for fertility preservation during this time; consultation occurred at median age 19 (range 16-24 years). Ten patients attempted and completed at least 1 semen collection. Eight patients cryopreserved semen before initiating treatment. Of those patients, all exhibited low morphology with otherwise normal median semen analysis parameters. In 1 patient who discontinued leuprolide acetate to attempt fertility preservation, transient azoospermia of 5 months' duration was demonstrated with subsequent recovery of spermatogenesis. In a patient who had previously been treated with spironolactone and estradiol, semen analysis revealed persistent azoospermia for the 4 months leading up to orchiectomy after discontinuation of both medications. CONCLUSIONS: Semen cryopreservation is a viable method of fertility preservation in adolescent and young adult transgender individuals and can be considered in patients who have already initiated therapy for gender dysphoria. Further research is needed to determine the optimal length of time these therapies should be discontinued to facilitate successful semen cryopreservation.

Autologous grafting of cryopreserved prepubertal rhesus testis produces sperm and offspring.

Testicular tissue cryopreservation is an experimental method to preserve the fertility of prepubertal patients before they initiate gonadotoxic therapies for cancer or other conditions. Here we provide the proof of principle that cryopreserved prepubertal testicular tissues can be autologously grafted under the back skin or scrotal skin of castrated pubertal rhesus macaques and matured to produce functional sperm. During the 8- to 12-month observation period, grafts grew and produced testosterone. Complete spermatogenesis was confirmed in all grafts at the time of recovery. Graft-derived sperm were competent to fertilize rhesus oocytes, leading to preimplantation embryo development, pregnancy, and the birth of a healthy female baby. Pending the demonstration that similar results are obtained in noncastrated recipients, testicular tissue grafting may be applied in the clinic.

The National Physicians Cooperative: transforming fertility management in the cancer setting and beyond.

Once unimaginable, fertility management is now a nationally established part of cancer care in institutions, from academic centers to community hospitals to private practices. Over the last two decades, advances in medicine and reproductive science have made it possible for men, women and children to be connected with an oncofertility specialist or offered fertility preservation soon after a cancer diagnosis. The Oncofertility Consortium's National Physicians Cooperative is a large-scale effort to engage physicians across disciplines - oncology, urology, obstetrics and gynecology, reproductive endocrinology, and behavioral health - in clinical and research activities to enable significant progress in providing fertility preservation options to children and adults. Here, we review the structure and function of the National Physicians Cooperative and identify next steps.

Female fertility preservation in the pediatric and adolescent cancer patient population.

The 5-year survival rate for childhood cancer is over 80%, thereby increasing the number of young women facing infertility in the future because of the gonadotoxic effects of chemotherapy and radiation. The gonadotoxic effects of childhood cancer treatment vary by the radiation regimen and the chemotherapeutic drugs utilized. Although the American Society of Clinical Oncology guidelines recommend fertility preservation for all patients, there are several barriers and ethical considerations to fertility preservation in the pediatric and adolescent female population. Additionally, the fertility preservation methods for pre- and postpubertal females differ, with only experimental methods available for prepubertal females. We will review the risk of chemotherapy and radiation on female fertility, the approach to fertility preservation in the pediatric and adolescent female population, methods of fertility preservation for both pre- and postpubertal females, barriers to fertility preservation, cost, and psychological and ethical considerations.