Ovarian cortex transplantation: time to move on from experimental studies to open clinical application

Exploring the Frontiers of Ovarian Tissue Cryopreservation: A Review

Objective: This paper serves as an up-to-date narrative review of the most effective methods and outcomes of ovarian tissue cryopreservation (OTC) with new data comparing this method to oocyte and embryo cryopreservation as well as its utility in restoration of endocrine function. Background: Data on OTC are becoming more available as more patients are achieving cancer remission and choosing to use their cryopreserved tissue to conceive or restore endocrine function. With OTC only recently becoming a non-experimental method of fertility preservation, it is important to evaluate, compare, and optimize current practices to improve live birth outcomes. Methods: A literature search of meta-analyses, systematic reviews, case series, retrospective studies, and randomized control trials was performed using the PubMed database with multiple search terms. Discussion: Current practices and outcomes of OTC remain heterogeneous, though they are becoming more streamlined with the emerging data on successful live births. Multiple aspects of OTC have been studied to optimize protocols, particularly methods of cryopreserving, in vitro maturation, and transplantation. In vitro follicle maturation is a novel application with emerging data on methods and outcomes. OTC is a versatile method not only for fertility preservation but also for hormone restoration as well. With wider usage of OTC, ethical dilemmas will need to be addressed. Conclusions: OTC can be used as fertility preservation for a variety of patients. Recent studies suggest it may be comparable to embryo cryopreservation, but with growing data on live births, comparative studies should continue to be performed. In vitro follicle maturation (IVFM) is a promising application of ovarian tissue harvesting. Data are lacking on cost-effectiveness, patient satisfaction, and morbidity associated with OTC.

De novo design of a nanoregulator for the dynamic restoration of ovarian tissue in cryopreservation and transplantation

The cryopreservation and transplantation of ovarian tissue underscore its paramount importance in safeguarding reproductive capacity and ameliorating reproductive disorders. However, challenges persist in ovarian tissue cryopreservation and transplantation (OTC-T), including the risk of tissue damage and dysfunction. Consequently, there has been a compelling exploration into the realm of nanoregulators to refine and enhance these procedures. This review embarks on a meticulous examination of the intricate anatomical structure of the ovary and its microenvironment, thereby establishing a robust groundwork for the development of nanomodulators. It systematically categorizes nanoregulators and delves deeply into their functions and mechanisms, meticulously tailored for optimizing ovarian tissue cryopreservation and transplantation. Furthermore, the review imparts valuable insights into the practical applications and obstacles encountered in clinical settings associated with OTC-T. Moreover, the review advocates for the utilization of microbially derived nanomodulators as a potent therapeutic intervention in ovarian tissue cryopreservation. The progression of these approaches holds the promise of seamlessly integrating nanoregulators into OTC-T practices, thereby heralding a new era of expansive applications and auspicious prospects in this pivotal domain.

Survival and hormone production of isolated mouse follicles in three-dimensional artificial scaffolds after stimulation with bpV(HOpic)

PURPOSE

To preserve fertility before gonadotoxic therapy, ovarian tissue can be removed, cryopreserved, and transplanted back again after treatment. An alternative is the artificial ovary, in which the ovarian follicles are extracted from the tissue, which reduces the risk of reimplantation of potentially remaining malignant cells. The PTEN inhibitor bpV(HOpic) has been shown to activate human, bovine and alpacas ovarian follicles, and it is therefore considered a promising substance for developing the artificial ovary. The purpose of this study was to examine the impact of different scaffolds and the vanadate derivative bpV(HOpic) on mice follicle survival and hormone secretion over 10 days.

METHODS

A comparative analysis was performed, studying the survival rates (SR) of isolated mice follicle in four different groups that differed either in the scaffold (polycaprolactone scaffold versus polyethylene terephthalate membrane) or in the medium-bpV(HOpic) versus control medium. The observation period of the follicles was 10 days. On days 2, 6, and 10, the viability and morphology of the follicles were checked using fluorescence or confocal microscopy. Furthermore, hormone levels of estrogen (pmol/L) and progesterone (nmol/L) were determined.

RESULTS

When comparing the SR of follicles among the four groups, it was observed that on day 6, the study groups utilizing the polycaprolactone scaffold with bpV(HOpic) in the medium (SR: 0.48 ± 0.18; p = 0.004) or functionalized in the scaffold (SR: 0.50 ± 0.20; p = 0.003) exhibited significantly higher survival rates compared to the group using only the polyethylene terephthalate membrane (SR: 0). On day 10, a significantly higher survival rate was only noted when comparing the polycaprolactone scaffold with bpV(HOpic) in the medium to the polyethylene terephthalate membrane group (SR: 0.38 ± 0.20 versus 0; p = 0.007). Higher levels of progesterone were only significantly associated with better survival rates in the group with the polycaprolactone scaffold functionalized with bpV(HOpic) (p = 0.017).

CONCLUSION

This study demonstrates that three-dimensional polycaprolactone scaffolds improve the survival rates of isolated mice follicles in comparison with a conventional polyethylene terephthalate membrane. The survival rates slightly improve with added bpV(HOpic). Furthermore, higher rates of progesterone were also partly associated with improved survival.

Fertility Preservation in Cervical Cancer-Treatment Strategies and Indications

Cervical cancer is frequently diagnosed in women during their reproductive years, and fertility preservation is an essential part of their cancer treatment. In highly selected patients with early stage, low-risk cervical cancer and a tumor size ≤ 2 cm, several treatment strategies can be offered for patients wishing to preserve fertility, including radical/simple trachelectomy or conization with pelvic lymph node assessment. Trachelectomy can be performed through a vaginal, abdominal, or minimally invasive approach and has been shown to have an equivalent oncologic outcome compared to radical hysterectomy. All surgical approaches for radical trachelectomy seem to have excellent survival with comparable oncologic outcomes. Nevertheless, patients undergoing vaginal trachelectomy have better obstetric outcomes compared to the other routes. In patients with larger tumors (2-4 cm), neoadjuvant chemotherapy followed by fertility-sparing surgery is an alternative option. Several chemotherapy regimens have been used for this indication, with a pathologic complete response rate of 17-73%. For locally advanced diseases that require radical hysterectomy or primary chemoradiation, fertility preservation can be performed using oocyte, embryo, or ovarian tissue cryopreservation, as well as ovarian transposition. For these patients, future pregnancy is possible through surrogacy. In addition to fertility preservation, ovarian transposition, where the ovaries are repositioned outside of the radiation field, is performed to maintain ovarian hormonal function and prevent premature ovarian failure. In summary, fertility-preservation treatment strategies for patients with early stage cervical cancer are continuously evolving, and less radical surgeries are becoming more acceptable. Additional and ongoing evidence is helping determine the impact of conservative procedures on oncologic and obstetric outcomes in these patients.

Preservation of Fertility in Cancer Patients: A Narrative Review

The survival rates for cancer patients have been steadily improving in recent years due to the improved efficacy of contemporary oncological care, including radiotherapy and chemotherapy. Modern technology makes it feasible to maintain fertility in cancer patients, and this practice needs to be included in oncological care. In many instances, it is impossible to avoid the harm that cancer treatments can cause to a patient's fertility; hence, research in fertility preservation techniques is being conducted to allow cancer patients to have future children biologically related to them. The development of fertility preservation approaches has grown in importance in the field of research over the past few years to increase patient's quality of life and survival. Oncologists must be aware of circumstances in which cancer patients' fertility will be impacted by their therapy and the avenues open for procedures like cryopreservation of the gametes or embryos. When cancer therapy is scheduled, all patients should receive prompt and thorough information on the fertility-related side effects of treatment and the prospects for fertility preservation. The article analyzes the literature, enlisting the factors that contribute to cancer and their effects on fertility, followed by a list of available and newly developed strategies for maintaining fertility in patients. The efficiency of the various fertility preservation techniques following cancer therapy is also discussed.

Exploring the Landscape of Social Egg Freezing: Navigating Medical Advancements, Ethical Dilemmas, and Societal Impacts

This narrative review article comprehensively explores the multifaceted landscape of social egg freezing, delving into its medical, ethical, societal, psychological, legal, and cultural dimensions. Oocyte cryopreservation, a developing procedure, gives women the chance to match their life goals with fertility goals. Informed decision-making, morally sound guidance, and open communication are all stressed by ethical considerations. Family planning practices, workplace cultures, and gender equality all have an impact on societal dynamics. The process's emotional toll and associated coping mechanisms are highlighted by psychological elements. Legal and policy frameworks need constant ethical reflection and understanding of the regulatory environment. Religious and cultural views highlight the variety of perspectives that influence attitudes toward this practice. For responsible practice to ensure individual liberty while navigating the evolving landscape of reproductive options, it is essential to comprehend how these aspects interact.

FOXO3 and PTEN expression in the ovary of girls with extra-gonadal cancer with or without chemotherapy treatment prior to cryopreservation

BACKGROUND

FOXO3/pFOXO3 and PTEN expression is known to regulate the dormancy/activation of ovarian primordial follicles. How chemotherapy could influence the expression of FOXO3 and PTEN in pre- and post-menarcheal girls with extra-gonadal cancer remains unexplored.

METHODS

Ovarian samples were collected from 27 girls suffering from extra-gonadal cancer. Of these, 8 patients had received chemotherapy before the time of sample collection. Ovarian tissue collected at the time of surgery was fixed in 10% formaldehyde for FOXO3/pFOXO3 and PTEN immunohistochemistry or immunofluorescence, or stored at -80 °C for Western blot, or preserved in RNA later for RT-PCR.

RESULTS

PTEN was detected in a limited number of primordial follicle-enclosed oocytes in approximately fifty percent of the patients, regardless of whether they had received anti-cancer treatment or not. However, there was a significant decrease in PTEN detection in patients who underwent chemotherapy treatment prior to the retrieval of the sample. Both primordial follicle-enclosed oocytes that expressed FOXO3 and those that did not were identified in patients who were treated with chemotherapy and those who were not. FOXO3-positive primordial follicles exhibited either nuclear FOXO3 localization or cytoplasmic pFOXO3 localization. Furthermore, transitional primordial follicles that expressed nuclear FOXO3 and cytoplasmic pFOXO3 were also observed. Primary follicle-enclosed oocytes displayed cytoplasmic pFOXO3 localization, whereas in more advanced stages of folliculogenesis, the expression moved to the somatic stratum. No significant statistical differences were identified in the detection of FOXO3 and pFOXO3 in patients who had or had not received chemotherapy prior to sample collection.

CONCLUSION

Primordial follicles expressing and not expressing FOXO3 were equally present in both the ovaries of patients who underwent chemotherapy and those who did not. The expression of FOXO3 remained unaltered in response to chemotherapy treatment. Notably, the detection of PTEN was significantly reduced in the treated patients, thereby warranting in-depth investigation, given the limited sample size examined in the present study.

Fertility Preservation in Children and Adolescents during Oncological Treatment-A Review of Healthcare System Factors and Attitudes of Patients and Their Caregivers

Oncofertility is any therapeutic intervention to safeguard the fertility of cancer patients. Anti-cancer therapies (chemotherapy, radiation therapy, etc.) entail the risk of reproductive disorders through cytotoxic effects on gamete-building cells, especially those not yet fully developed. This literature review analyzes the available data on securing fertility in pediatric and adolescent populations to identify the methods used and describe aspects related to financing, ethics, and the perspective of patients and their parents. Topics related to oncofertility in this age group are relatively niche, with few peer-reviewed articles available and published studies mostly on adults. Compared to pubertal individuals, a limited number of fertility preservation methods are used for prepubertal patients. Funding for the procedures described varies from country to country, but only a few governments choose to reimburse them. Oncofertility of pediatric and adolescent patients raises many controversies related to the decision, parents' beliefs, having a partner, ethics, as well as the knowledge and experience of healthcare professionals. As the fertility of young cancer patients is at risk, healthcare professionals should make every effort to provide them with an opportunity to fulfill their future reproductive plans and to have a family and offspring. Systemic solutions should form the basis for the development of oncofertility in pediatric and adolescent populations.

Rescue of follicle development after oocyte-induced ovary dysfunction and infertility in a model of POI

The mechanisms and aetiology underlying the development of premature ovarian insufficiency (POI) are poorly understood. However, the oocyte clearly has a role as demonstrated by the Double Mutant (DM) mouse model where ovarian dysfunction (6 weeks) is followed by POI (3 months) due to oocyte-specific deletion of complex and hybrid N- and O-glycans. The ovaries of DM mice contain more primary follicles (3a stage) accompanied by fewer developing follicles, indicating a block in follicle development. To investigate this block, we first analysed early follicle development in postnatal (8-day), pre-pubertal (3-week) and post-pubertal (6-week and 3-month) DM (C1galt1 F/F Mgat1 F/F:ZP3Cre) and Control (C1galt1 F/F Mgat1 F/F) mice. Second, we investigated if transplantation of DM ovaries into a "normal" endocrine environment would restore follicle development. Third, we determined if replacing DM ovarian somatic cells would rescue development of DM oocytes. At 3-week, DM primary 3a follicles contain large oocytes accompanied by early development of a second GC layer and increased GC proliferation. At 6-week, DM primary 3a follicles contain abnormally large oocytes, accompanied with decreased GC proliferation. Transplantation of DM ovaries into a 'normal' endocrine environment did not restore normal follicle development. However, replacing somatic cells by generating reaggregated ovaries (ROs) did enable follicle development to progress and thus highlighted intra-ovarian factors were responsible for the onset of POI in DM females. Thus, these studies demonstrate oocyte-initiated altered communication between GCs and oocytes results in abnormal primary follicles which fail to progress and leads to POI.

Importance of oxygen tension in human ovarian tissue in vitro culture

STUDY QUESTION

Is there any difference between 20% and 5% oxygen (O2) tension in vitro culture (IVC) on the viability and quality of human follicles contained in cultured ovarian cortex?

SUMMARY ANSWER

An O2 tension of 5% yields higher follicle viability and quality than does 20% O2 tension after 6 days of IVC.

WHAT IS KNOWN ALREADY

The primordial follicle (PMF) pool resides within the ovarian cortex, where the in vivo O2 tension ranges between 2% and 8%. Some studies suggest that lowering O2 tension to physiological levels may improve in vitro follicle quality rates.

STUDY DESIGN, SIZE, DURATION

This prospective experimental study included frozen-thawed ovarian cortex from six adult patients (mean age: 28.5 years; age range: 26-31 years) who were undergoing laparoscopic surgery for non-ovarian diseases. Ovarian cortical fragments were cultured for 6 days at (i) 20% O2 with 5% CO2 and (ii) 5% O2 with 5% CO2. Non-cultured fragments served as controls.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Cortical fragments were used for the following analyses: hematoxylin and eosin staining for follicle count and classification; Ki67 staining to evaluate PMF proliferation; cleaved caspase-3 immunostaining to identify follicle apoptosis; 8-hydroxy-2-deoxyguanosine and gamma-H2AX (γH2AX) immunolabeling to detect oxidative stress damage and DNA double-strand breaks (DSBs) in oocytes and granulosa cells (GCs); and β-galactosidase staining to assess follicle senescence. Droplet digital PCR was also performed to further explore the gene expression of superoxide dismutase 2 (SOD2) and glutathione peroxidase 4 (GPX4) from the antioxidant defense system and cyclin-dependent kinase inhibitors (p21 and p16) as tissue senescence-related genes.

MAIN RESULTS AND THE ROLE OF CHANCE

Apoptosis (P = 0.002) and follicle senescence (P < 0.001) rates were significantly lower in the 5% O2 group than in the 20% O2 group. Moreover, GCs in follicles in the 20% O2 group exhibited significantly (P < 0.001) higher oxidative stress damage rates than those in the 5% O2 group. DNA DSB damage rates in GCs of follicles were also significantly higher (P = 0.001) in the 20% O2 group than in the 5% O2 group. SOD2 expression was significantly greater in the 5% O2 group compared to the 20% O2 group (P = 0.04) and the non-cultured group (P = 0.002). Expression of p21 was significantly increased in both the 20% O2 (P = 0.03) and 5% O2 (P = 0.008) groups compared to the non-cultured group. Moreover, the 20% O2 group showed significantly greater p16 expression (P = 0.04) than the non-cultured group, while no significant variation was observed between the 5% O2 and no culture groups.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This study focuses on improving follicle outcomes during the first step of ovarian tissue IVC, where follicles remain in situ within the tissue. The impact of O2 tension in further steps, such as secondary follicle isolation and maturation, was not investigated here.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that 5% O2 tension culture is a promising step toward potentially solving the problem of poor follicle viability after IVC.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (FNRS-PDR T.0064.22, CDR J.0063.20 and grant 5/4/150/5 awarded to M.M.D.). The authors have nothing to disclose.

Fertility preservation in pediatric healthcare: a review

Survival rates for children and adolescents diagnosed with malignancy have been steadily increasing due to advances in oncology treatments. These treatments can have a toxic effect on the gonads. Currently, oocyte and sperm cryopreservation are recognized as well-established and successful strategies for fertility preservation for pubertal patients, while the use of gonadotropin-releasing hormone agonists for ovarian protection is controversial. For prepubertal girls, ovarian tissue cryopreservation is the sole option. However, the endocrinological and reproductive outcomes after ovarian tissue transplantation are highly heterogeneous. On the other hand, immature testicular tissue cryopreservation remains the only alternative for prepubertal boys, yet it is still experimental. Although there are several published guidelines for navigating fertility preservation for pediatric and adolescent patients as well as transgender populations, it is still restricted in clinical practice. This review aims to discuss the indications and clinical outcomes of fertility preservation. We also discuss the probably effective and efficient workflow to facilitate fertility preservation.

Effects of needle puncturing on re-vascularization and follicle survival in xenotransplanted human ovarian tissue

BACKGROUND

Ovarian tissue transplantation can restore fertility in young cancer survivors, however the detrimental loss of follicles following transplantation of cryopreserved ovarian tissue is hampering the efficiency of the procedure. This study investigates whether needle puncturing prior to transplantation can enhance revascularization and improve follicle survival in xenotransplanted human ovarian cortex.

METHODS

Cryopreserved human ovarian cortex pieces (N = 36) from 20 women aged 24-36 years were included. During the thawing process, each piece of tissue was cut in halves; one half serving as the untreated control and the other half was punctured approximately 150-200 times with a 29-gauge needle. The cortex pieces were transplanted subcutaneously to immunodeficient mice for 3, 6 and 10 days (N = 8 patients) and for 4 weeks (N = 12 patients). After 3, 6 and 10 days, revascularization of the ovarian xenografts were assessed using immunohistochemical detection of CD31 and gene expression of angiogenic factors (Vegfα, Angptl4, Ang1, and Ang2), and apoptotic factors (BCL2 and BAX) were performed by qPCR. Follicle density and morphology were evaluated in ovarian xenografts after 4 weeks.

RESULTS

A significant increase in the CD31 positive area in human ovarian xenografts was evident from day 3 to 10, but no significant differences were observed between the needle and control group. The gene expression of Vegfα was consistently higher in the needle group compared to control at all three time points, but not statistically significant. The expression of Ang1 and Ang2 increased significantly from day 3 to day 10 in the control group (p < 0.001, p = 0.0023), however, in the needle group this increase was not observed from day 6 to 10 (Ang2 p = 0.027). The BAX/BCL2 ratio was similar in the needle and control groups. After 4-weeks xenografting, follicle density (follicles/mm³, mean ± SEM) was higher in the needle group (5.18 ± 2.24) compared to control (2.36 ± 0.67) (p = 0.208), and a significant lower percentage of necrotic follicles was found in the needle group (19%) compared to control (36%) (p = 0.045).

CONCLUSIONS

Needle puncturing of human ovarian cortex prior to transplantation had no effect on revascularization of ovarian grafts after 3, 6 and 10 days xenotransplantation. However, needle puncturing did affect angiogenic genes and improved follicle morphology.

Turner syndrome: fertility counselling in childhood and through the reproductive lifespan

PURPOSE OF REVIEW

The potential for fertility in Turner syndrome has improved in recent years. Understanding of associated risks and approaches is important for the care of girls and women with this condition. This review focuses on reproductive health, fertility options and appropriate counselling for women with Turner syndrome and their families.

RECENT FINDINGS

Women with Turner syndrome have rapidly declining ovarian function beginning in utero . Therefore, counselling regarding fertility concerns should begin at a young age and involve discussion of options, including ovarian tissue cryopreservation, oocyte preservation and use of nonautologous oocytes. Clinical guidance on fertility management and pregnancy risk assessment based on karyotype, associated comorbidities and fertility is still not fully data driven. Realistic expectations regarding reproductive options and associated outcomes as well as the need for multidisciplinary follow-up during pregnancy are crucial to the ethical and safe care of these patients.

SUMMARY

Fertility care in women with Turner syndrome is evolving as current management techniques improve and new approaches are validated. Early counselling and active management of fertility preservation is critical to ensure positive and well tolerated reproductive outcomes.

The use of near-infrared imaging with indocyanine green in the ovarian tissue transplantation: a case report

The request for fertility preservation has consistently increased in recent years. To our knowledge this case report is the first to describe the application of near-infrared intraoperative imaging using indocyanine green (NIR-ICG) during ovarian tissue transplantation (OTT), to assist surgeon choosing the site of implantation of ovarian fragments. OTT was performed in a 42-year-old woman using NIR-ICG to evaluate the vascularisation of peritoneal area as the site of implantation for the ovarian graft. we believe this new approach could be useful in identifying the best reimplantation site.

Multi-biofunctional graphene oxide-enhanced poly-L-lactic acid composite nanofiber scaffolds for ovarian function recovery of transplanted-tissue

In this study, we successfully constructed the new graphene oxide/poly-L-lactic acid (GO/PLLA) nanofiber scaffolds with a hydrophilic surface and porous network structure that were highly favorable for cell infiltration. When employed these new nanofiber scaffolds for a wide range of tissue engineering applications, it was expected to promote graft tissue survival and angiogenesis. The new GO/PLLA nanofiber scaffold with an appropriate concentration of 1.0 wt% was applied for the restoration of ovarian function and reserve in mice with primary ovarian insufficiency (POI). After co-transplanting the normal ovarian cortex loaded on these new nanomaterials into the in situ ovarian tissue of POI mice, the fusion of transplanted ovarian cortex with damaged ovarian tissue was improved, as well as the ovarian function and the follicle numbers. Moreover, angiogenesis was observed clearly and proved to exist in the transplanted tissue and nanomaterials, with the most conspicuous effect after co-transplantation with 1.0 wt% GO/PLLA nanofiber scaffold. In addition, nitric oxide (NO) production by phosphorylated endothelial nitric oxide synthase (p-eNOS) in vivo was proven to be involved in the effect of GO and PLLA on the improved survival rate of the transplanted ovarian cortex. This study provides a new method for the fertility preservation of ovarian tissue cryopreservation and transplantation, as well as a new strategy for the transplantation of other organs.

Follicle isolation methods reveal plasticity of granulosa cell steroidogenic capacity during mouse in vitro follicle growth

Follicles are the functional unit of the ovary and several methods have been developed to grow follicles ex vivo, which recapitulate key events of oogenesis and folliculogenesis. Enzymatic digestion protocols are often used to increase the yield of follicles from the ovary. However, the impact of these protocols on the outermost theca and granulosa cells, and thereby follicle function, is not well defined. To investigate the impact of enzymatic digestion on follicle function, we collected preantral follicles from CD1 mice either by enzymatic digestion (Enzy-FL) or mechanical isolation (Mech-FL) and compared follicle growth, steroidogenesis and cell differentiation within an encapsulated in vitro follicle growth system which maintains the 3D architecture of the oocyte and its surrounding somatic cells. Follicles were encapsulated in 0.5% alginate and cultured for 8 days. Compared with Enzy-FL, Mech-FL grew more rapidly and produced significantly higher levels of androstenedione, estradiol and progesterone. The expression of theca-interstitial cell marker genes, Cyp17a1, which encodes 17-hydroxylase/17, 20-lyase and catalyzes the hydroxylation of pregnenolone and progesterone to 17-hydroxypregnenolone and 17-hydroxyprogesterone, and the conversion of these products into dehydroepiandrosterone and androstenedione, and Star, which encodes a transport protein essential for cholesterol entry into mitochondria, were also higher in Mech-FL than in Enzy-FL. Mech-FL maintained an intact theca-interstitial layer on the outer edge of the follicle that phenocopied in vivo patterns as confirmed by alkaline phosphatase staining, whereas theca-interstitial cells were absent from Enzy-FL from the onset of culture. Therefore, preservation of the theca cell layer at the onset of culture better supports follicle growth and function. Interestingly, granulosa cells in the outermost layers of Enzy-FL expressed CYP17A1 by Day 4 of culture while maintaining inhibin α-subunit expression and a cuboidal nucleus. Thus, in the absence of theca-interstitial cells, granulosa cells have the potential to differentiate into androgen-producing cells. This work may have implications for human follicle culture, where enzymatic isolation is required owing to the density of the ovarian cortex.

Ovarian Tissue Cryopreservation in Children and Adolescents

Cancer during childhood and adolescence remains a major public health issue, affecting a significant portion of this age group. Although newer anti-cancer treatments have improved survival rates, this comes at a cost in terms of gonadotoxic effects. As a result, the preservation of fertility is important. Ovarian tissue cryopreservation, one of the newest methods, has some advantages, especially for prepubertal patients: no need for ovarian stimulation, thus, no further risk for estrogen-sensitive cancer types, and preservation of more and better-quality primordial follicles of the ovarian cortex. The most frequent indications include treatment with alkylating agents, ovarian-focused radiotherapy, leukemias, lymphomas, brain and neurological tumors, as well as Turner syndrome and benign hemoglobinopathies. An expected survival exceeding 5 years, the absence of systematic disease and an overall risk of premature ovarian insufficiency over 50% are among the criteria that need to be fulfilled in order for a patient to undertake this method. Orthotopic transplantation is more frequently used, since it can allow both live birth and the recovery of endocrine function. Reimplantation of malignant cells is always a major risk and should always be taken into consideration. Histological analysis, as well as immunohistochemical and molecular methods, are needed in order to improve the search for malignant cells before transplantation. Ovarian tissue cryopreservation appears to be a method with specific benefits, indications and risks which can be an important tool in terms of preserving fertility in younger women.

Age-related fertility decline: is there a role for elective ovarian tissue cryopreservation?

Age-related fertility decline (ARFD) is a prevalent concern amongst western cultures due to the increasing age of first-time motherhood. Elective oocyte and embryo cryopreservation remain the most established methods of fertility preservation, providing women the opportunity of reproductive autonomy to preserve their fertility and extend their childbearing years to prevent involuntary childlessness. Whilst ovarian cortex cryopreservation has been used to preserve reproductive potential in women for medical reasons, such as in pre- or peripubertal girls undergoing gonadotoxic chemotherapy, it has not yet been considered in the context of ARFD. As artificial reproductive technology (ART) and surgical methods of fertility preservation continue to evolve, it is a judicious time to review current evidence and consider alternative options for women wishing to delay their fertility. This article critically appraises elective oocyte cryopreservation as an option for women who use it to mitigate the risk of ARFD and introduces the prospect of elective ovarian cortex cryopreservation as an alternative.

Fertility preservation for patients with cancer

Background: The survival rate of cancer patients is increasing owing to the early diagnosis and treatment methods. Radiotherapy and chemotherapy may cause serious complications, such as ovarian failure and infertility. In particular, preservation of fertility in women of reproductive age with cancer could improve their quality of life as well as reduce social and psychological pain.Current Concepts: Embryo or oocyte cryopreservation is a method of fertility preservation; however, it cannot be utilized by all women with cancer because of the complications of the condition and treatment method. Ovarian tissue cryopreservation and transplantation enables fertility preservation in those needing immediate cancer treatment, such as chemotherapy or radiotherapy, or those unqualified for ovarian stimulation. A recent review reported that frozen-thawed ovarian transplantation led to approximately 130 live births with a conception rate of approximately 30%. Endocrine function recovery occurred in 92.9% of the patients between 3.5 and 6.5 months after transplantation.Discussion and Conclusion: In this study, we introduced various methods and strategies for improving the outcomes of ovarian tissue cryopreservation and transplantation. These results could serve as a reference for patients and clinicians to choose the best options for fertility preservation based on the patient’s current situation and condition.

Fertility after Cancer: Risks and Successes

Simple Summary

Approximately one million new cases of cancer are diagnosed in women of reproductive age every year. In the last few decades, advances in early diagnosis and treatment have improved the survival rate. However, the adverse effects of anticancer therapy on the ovaries and uterus have a significant impact on future fertility and may affect the quality of life of cancer survivors. Unfortunately, evidence about the trend of ovarian reserve loss over time is insufficient for predicting the duration of the fertile period. Currently, impaired fertility in cancer survivors is a growing issue that is complicated by an increasing number of women delaying childbearing. This review focuses on the detrimental effects of chemotherapy, radiotherapy, and surgery on reproductive functions and describes the mechanisms causing reduced fertility in cancer survivors. Moreover, in this review, the available fertility preservation strategies to guarantee the chance of motherhood in cancer survivors are illustrated.

Abstract

The incidence of cancer in reproductive-aged women is 7%, but, despite the increased number of cancer cases, advances in early diagnosis and treatment have raised the survival rate. Furthermore, in the last four decades, there has been a rising trend of delaying childbearing. There has been an increasing number of couples referred to Reproductive Medicine Centers for infertility problems after one partner has been treated for cancer. In these cases, the main cause of reduced fertility derives from treatments. In this review, we describe the effects and the risks of chemotherapy, radiotherapy, and surgery in women with cancer, and we will focus on available fertility preservation techniques and their efficacy in terms of success in pregnancy and live birth rates.

Fresh and cryopreserved ovarian tissue transplantation for preserving reproductive and endocrine function: a systematic review and individual patient data meta-analysis

BACKGROUND

Ovarian tissue cryopreservation involves freezing and storing of surgically retrieved ovarian tissue in liquid or vapour nitrogen below -190°C. The tissue can be thawed and transplanted back with the aim of restoring fertility or ovarian endocrine function. The techniques for human ovarian tissue freezing and transplantation have evolved over the last 20 years, particularly in the context of fertility preservation in pre-pubertal cancer patients. Fresh ovarian tissue transplantation, using an autograft or donor tissue, is a more recent development; it has the potential to preserve fertility and hormonal function in women who have their ovaries removed for benign gynaecological conditions. The techniques of ovarian tissue cryopreservation and transplantation have progressed rapidly since inception; however, the evidence on the success of this intervention is largely based on case reports and case series.

OBJECTIVE AND RATIONALE

The aim of this study was to systematically review the current evidence by incorporating study-level and individual patient-level meta-analyses of women who received ovarian transplants, including frozen-thawed transplant, fresh or donor graft.

SEARCH METHODS

The review protocol was registered with PROSPERO (CRD42018115233). A comprehensive literature search was performed using MEDLINE, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials from database inception to October 2020. Authors were also contacted for individual patient data if relevant outcomes were not reported in the published manuscripts. Meta-analysis was performed using inverse-variance weighting to calculate summary estimates using a fixed-effects model.

OUTCOMES

The review included 87 studies (735 women). Twenty studies reported on ≥5 cases of ovarian transplants and were included in the meta-analysis (568 women). Fertility outcomes included pregnancy, live birth and miscarriage rates, and endocrine outcomes included oestrogen, FSH and LH levels. The pooled rates were 37% (95% CI: 32-43%) for pregnancy, 28% (95% CI: 24-34%) for live birth and 37% (95% CI: 30-46%) for miscarriage following frozen ovarian tissue transplantation. Pooled mean for pre-transplant oestrogen was 101.6 pmol/l (95% CI: 47.9-155.3), which increased post-transplant to 522.4 pmol/l (95% CI: 315.4-729; mean difference: 228.24; 95% CI: 180.5-276). Pooled mean of pre-transplant FSH was 66.4 IU/l (95% CI: 52.8-84), which decreased post-transplant to 14.1 IU/l (95% CI: 10.9-17.3; mean difference 61.8; 95% CI: 57-66.6). The median time to return of FSH to a value <25 IU/l was 19 weeks (interquartile range: 15-26 weeks; range: 0.4-208 weeks). The median duration of graft function was 2.5 years (interquartile range: 1.4-3.4 years; range: 0.7-5 years). The analysis demonstrated that ovarian tissue cryopreservation and transplantation could restore reproductive and hormonal functions in women. Further studies with larger samples of well-characterized populations are required to define the optimal retrieval, cryopreservation and transplantation processes.

WIDER IMPLICATIONS

Ovarian tissue cryopreservation and transplantation may not only be effective in restoring fertility but also the return of reproductive endocrine function. Although this technology was developed as a fertility preservation option, it may have the scope to be considered for endocrine function preservation.

A comparison of fertility preservation outcomes in patients who froze oocytes, embryos, or ovarian tissue for medically indicated circumstances: a systematic review and meta-analysis

OBJECTIVE

To compare obstetric outcomes in patients cryopreserving reproductive cells or tissues before gonadotoxic therapy.

DESIGN

A literature search was conducted following PRISMA guidelines on Embase, Medline, and Web of Science. Studies reporting obstetric outcomes in cancer patients who completed cryopreservation of oocyte, embryo, or ovarian tissue were included.

SETTING

Not applicable.

PATIENT(S)

Cancer patients attempting pregnancy using cryopreserved cells or tissues frozen before cancer therapy.

INTERVENTION(S)

Oocyte, embryo, or ovarian tissue cryopreservation for fertility preservation in cancer.

MAIN OUTCOME MEASURE(S)

The total numbers of clinical pregnancies, live births, and miscarriages in women attempting pregnancy using cryopreserved reproductive cells or tissues were calculated. A meta-analysis determined the effect size of each intervention.

RESULT(S)

The search returned 4,038 unique entries. Thirty-eight eligible studies were analyzed. The clinical pregnancy rates were 34.9%, 49.0%, and 43.8% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. No significant differences were found among groups. The live birth rates were 25.8%, 35.3%, and 32.3% for oocyte, embryo, and ovarian tissue cryopreservation, respectively, with no significant differences among groups. The miscarriage rates were 9.2%, 16.9%, and 7.5% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. Significantly fewer miscarriages occurred with ovarian tissue cryopreservation than with embryo cryopreservation.

CONCLUSION(S)

This enquiry is required to counsel cancer patients wishing to preserve fertility. Although the limitations of this study include heterogeneity, lack of quality studies, and low utilization rates, it serves as a starting point for comparison of reproductive and obstetric outcomes in patients returning for family-planning after gonadotoxic therapy.

The Experience of Fertility Preservation in a Single Tertiary Center in Korea

OBJECTIVE

Oocyte (OC), embryo (EC), and ovarian tissue cryopreservation (OTC) are options for fertility preservation (FP) before going through gonadotoxic cancer treatment, or anticipated fertility decline in benign ovarian diseases, or for planned OC. The aim of this study is to report outcomes of FP in a single tertiary hospital in Korea.

METHODS

This is a retrospective study of OC, EC, and OTC cycles. All patients who visited or were referred to the infertility clinic at the Department of Obstetrics and Gynecology for the purpose of FP between 2010 and October 2021 were included.

RESULTS

A total of 564 controlled ovarian stimulation cycles were conducted in 416 women. Three hundred fifty-seven women underwent 494 OC cycles. Most patients were diagnosed with breast cancer (22.4%), followed by endometriomas (21.9%), and then by planned OC (20.7%). Cases of OC have increased over the years, peaking at 109 cycles in 2019 compared to one in 2010. Fifty-nine women underwent 70 EC cycles, and breast cancer (50.8%) was the most common indication. Repetitive OC and EC cycles were undergone in 92 and 9 women, respectively (mean number of repetition, 1.37 and 1.19 times in OC and EC, respectively), yielding a maximum number of 33 oocytes or 23 embryos being cryopreserved per patient. The utilization rate was 3.1% (11/357) in OC and 16.9% (10/59) in EC. Twenty-six women underwent OTC, and gynecologic cancer was the most common indication (9/26, 34.6%). One woman had the cryopreserved ovarian tissue retransplanted and successfully generated embryos.

CONCLUSION

OC, EC, and OTC are possible options for preserving fertility, and these opportunities should be provided for women at risk of fertility decline or those who are eager to protect their future fertility. This is the first report on long-term FP outcomes in a single tertiary center in Korea. We expect that there will be more cases over the years and more women returning to use their gametes or embryos for pregnancy.

Fertility Preservation for Prepubertal Patients at Risk of Infertility: Present Status and Future Perspectives

The increasing cure rate of cancer has led to a vast population of survivors having to face the late adverse effects of oncological treatments, with fertility impairment being one of the most sensitive issues for patients. Different options to preserve the fertility of adult patients are routinely used in clinical practice. However, fertility preservation strategies for prepubertal patients at risk of infertility are limited to the cryopreservation of immature gonadal tissue. In recent decades, many research efforts have been focused on the future use of cryopreserved gonadal tissue. This review discusses the common status of fertility preservation measures for pediatric patients undergoing gonadotoxic treatment, focusing especially on the challenges that remain to be solved in order to implement this fundamental service.

Female Oncofertility: Current Understandings, Therapeutic Approaches, Controversies, and Future Perspectives

Recent advances in early detection and oncological therapies have ameliorated the survival rate of young cancer patients. Yet, ovarian impairment induced by chemotherapy and radiotherapy is still a challenging issue. This review, based on clinical and lab-based studies, summarizes the evidence of gonadotoxicity of chemoradiotherapy, the recent approaches, ongoing controversies, and future perspectives of fertility preservation (FP) in female patients who have experienced chemo- or radio-therapy. Existing data indicate that chemotherapeutic agents induce DNA alterations and massive follicle activation via the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. Meanwhile, the radiation causes ionizing damage, leading to germ cell loss. In addition to the well-established methods, numerous therapeutic approaches have been suggested, including minimizing the follicle loss in cryopreserved ovarian grafts after transplantation, in vitro activation or in vitro growing of follicles, artificial ovarian development, or fertoprotective adjuvant to prevent ovarian damage from chemotherapy. Some reports have revealed positive outcomes from these therapies, whereas others have demonstrated conflictions. Future perspectives are improving the live birth rate of FP, especially in patients with adverse ovarian reserve, eliminating the risk of malignancy reintroducing, and increasing society’s awareness of FP importance.

Fertility Preservation: How to Preserve Ovarian Function in Children, Adolescents and Adults

Chemotherapy, pelvic radiotherapy and ovarian surgery have known gonadotoxic effects that can lead to endocrine dysfunction, cessation of ovarian endocrine activity and early depletion of the ovarian reserve, causing a risk for future fertility problems, even in children. Important determinants of this risk are the patient’s age and ovarian reserve, type of treatment and dose. When the risk of premature ovarian insufficiency is high, fertility preservation strategies must be offered to the patient. Furthermore, fertility preservation may sometimes be needed in conditions other than cancer, such as in non-malignant diseases or in patients seeking fertility preservation for personal reasons. Oocyte and/or embryo vitrification and ovarian tissue cryopreservation are the two methods currently endorsed by the American Society for Reproductive Medicine, yielding encouraging results in terms of pregnancy and live birth rates. The choice of one technique above the other depends mostly on the age and pubertal status of the patient, and personal and medical circumstances. This review focuses on the available fertility preservation techniques, their appropriateness according to patient age and their efficacy in terms of pregnancy and live birth rates.

Establishment of a Pediatric Ovarian and Testicular Cryopreservation Program for Malignant and Non-Malignant Conditions: The Mayo Clinic Experience

STUDY OBJECTIVES

To describe the structure of a pediatric fertility preservation (FP) program and to share safety and patient satisfaction data.

DESIGN

The FP program operates under prospective research protocols approved by the Mayo Clinic Institutional Review Board (IRB).

SETTING

The FP program is a multidisciplinary effort between pediatric gynecology, reproductive endocrinology, pediatric urology, pediatric surgery, and laboratory medicine.

PARTICIPANTS

The FP program enrolls patients between 0-17 years of age who have been diagnosed with a fertility-threatening condition and/or are scheduled to undergo gonadotoxic treatment.

INTERVENTIONS

FP is offered in the form of ovarian tissue cryopreservation (OTC) and testicular (TTC) tissue cryopreservation.

MAIN OUTCOME MEASURES

The outcome measures are the safety of the procedure and results of patient surveys conducted by phone using a standard list of questions to assess attitudes towards FP.

RESULTS

To date, we have enrolled 38 OTC and 37 TTC patients. The median age (range) of OTC and TTC patients was 11 years (0.83-17 years) and 10 years (0.92-17 years) at the time of enrollment, respectively. Childhood cancers currently represent 88% of the fertility-threatening diagnoses. Meanwhile, patients with non-malignant conditions include those with gender dysphoria, aplastic anemia, and Turner's syndrome. To date, no serious adverse events (SAEs) have been reported following surgery. According to n = 34 one-year follow-ups, 100% of parents felt that FP was a good decision.

CONCLUSION

Consistent with the literature, our data suggests FP is safe and improves the quality of care provided to pediatric patients for their fertility-threatening diagnoses and/or treatments.

TRIAL REGISTRATION

NCT02872532, NCT02646384.

Fertility-sparing surgery and fertility preservation in cervical cancer: The desire for parenthood, reproductive and obstetric outcomes

OBJECTIVE

To evaluate the desire for parenthood and reproductive outcomes of young cervical cancer survivors who underwent fertility-sparing surgery or fertility preservation procedures for invasive cervical cancer.

METHODS

All women <45 years who underwent fertility-sparing treatment for invasive cervical cancer in a tertiary referral center in the Netherlands between January 2009 and January 2020 were identified. Fertility-sparing treatment options included Vaginal Radical Trachelectomy (VRT) for patients with early-stage disease and fertility preservation techniques (FP) when requiring Radical Hysterectomy (RH) or chemoradiotherapy. Data on reproductive intentions - and outcomes were retrieved from medical files and questionnaires.

RESULTS

75 patients were identified of whom 34 underwent VRT, 9 RH and 32 had (chemo)radiotherapy. 26 patients started FP of whom 23 (88.5%) successfully preserved fertility through cryopreservation of embryos, oocytes and ovarian tissue. After a median follow-up of 49 months, 5 patients developed recurrent disease and died. Reproductive outcomes were retrieved in 58 patients. 89.6% maintained their desire for parenthood after cancer treatment. Following VRT, we report a pregnancy rate of 61.9% among the patients attempting conception (n = 24). 15 patients conceived 21 pregnancies which resulted in 15 live-births, yielding a live-birth rate of 75.0%. Following RH or (chemo)radiotherapy, 3 surrogate pregnancies were established (21.4%) using frozen-thawed material with good neonatal outcomes.

CONCLUSION

Many cervical cancer survivors maintain the desire to become parents eventually. In early-stage disease, VRT shows good reproductive outcomes without compromising oncological safety. For those requiring gonadotoxic treatment fertility preservation and gestational surrogacy provides a promising alternative for achieving a biological offspring.

Translational Physiology of Anti-Müllerian Hormone: Clinical Applications in Female Fertility Preservation and Cancer Treatment

Background

Whilst the ability of AMH to induce the regression of the Müllerian ducts in the male fetus is well appreciated, AMH has additional biological actions in relation to steroid biosynthesis and ovarian follicle dynamics. An understanding of the physiology of AMH illuminates the potential therapeutic utility of AMH to protect the ovarian reserve during chemotherapy and in the treatment of female malignancies. The translation of the biological actions of AMH into clinical applications is an emerging focus of research, with promising preliminary results.

Objective and Rationale

Studies indicate AMH restrains primordial follicle development, thus administration of AMH during chemotherapy may protect the ovarian reserve by preventing the mass activation of primordial follicles. As AMH induces regression of tissues expressing the AMH receptor (AMHRII), administration of AMH may inhibit growth of malignancies expressing AMHR II. This review evaluates the biological actions of AMH in females and appraises human clinical applications.

Search Methods

A comprehensive search of the Medline and EMBASE databases seeking articles related to the physiological functions and therapeutic applications of AMH was conducted in July 2021. The search was limited to studies published in English.

Outcomes

AMH regulates primordial follicle recruitment and moderates sex steroid production through the inhibition of transcription of enzymes in the steroid biosynthetic pathway, primarily aromatase and 17α-hydroxylase/17,20-lyase. Preliminary data indicates that administration of AMH to mice during chemotherapy conveys a degree of protection to the ovarian reserve. Administration of AMH at the time of ovarian tissue grafting has the potential to restrain uncontrolled primordial follicle growth during revascularization. Numerous studies demonstrate AMH induced regression of AMHR II expressing malignancies. As this action occurs via a different mechanism to traditional chemotherapeutic agents, AMH has the capacity to inhibit proliferation of chemo-resistant ovarian cancer cells and cancer stem cells.

Wider Implications

To date, AMH has not been administered to humans. Data identified in this review suggests administration of AMH would be safe and well tolerated. Administration of AMH during chemotherapy may provide a synchronistic benefit to women with an AMHR II expressing malignancy, protecting the ovarian reserve whilst the cancer is treated by dual mechanisms.

Regional air transportation of ovarian tissue for cryopreservation in a prepubertal female with cancer

Ovarian tissue cryopreservation is the only fertility preservation (FP) option available to prepubescent females receiving gonadotoxic therapy, but it has limited availability. A 6-year-old female was diagnosed with high-risk rhabdomyosarcoma, and the planned treatment carried an 80% risk of ovarian failure. Her parents desired FP, but the nearest center was 500 miles away. The patient underwent oophorectomy at the cancer center with air transport of the tissue to the oncofertility center, where it was successfully cryopreserved. Formation of networks between full-service and limited oncofertility centers in a hub-and-spoke model would increase access to FP services, particularly in children.

Oocyte cryopreservation versus ovarian tissue cryopreservation for adult female oncofertility patients: a cost-effectiveness study

PURPOSE

In December 2019, the American Society for Reproductive Medicine designated ovarian tissue cryopreservation (OTC) as no longer experimental and an alternative to oocyte cryopreservation (OC) for women receiving gonadotoxic therapy. Anticipating increased use of OTC, we compare the cost-effectiveness of OC versus OTC for fertility preservation in oncofertility patients.

METHODS

A cost-effectiveness model to compare OC versus OTC was built from a payer perspective. Costs and probabilities were derived from the literature. The primary outcome for effectiveness was the percentage of patients who achieved live birth. Strategies were compared using incremental cost-effectiveness ratios (ICER). All inputs were varied widely in sensitivity analyses.

RESULTS

In the base case, the estimated cost for OC was $16,588 and for OTC $10,032, with 1.56% achieving live birth after OC, and 1.0% after OTC. OC was more costly but more effective than OTC, with an ICER of $1,163,954 per live birth. In sensitivity analyses, OC was less expensive than OTC if utilization was greater than 63%, cost of OC prior to chemotherapy was less than $8100, cost of laparoscopy was greater than $13,700, or standardized discounted costs were used.

CONCLUSIONS

With current published prices and utilization, OC is more costly but more effective than OTC. OC becomes cost-saving with increased utilization, when cost of OC prior to chemotherapy is markedly low, cost of laparoscopy is high, or standardized discounted oncofertility pricing is assumed. We identify the critical thresholds of OC and OTC that should be met to deliver more cost-effective care for oncofertility patients.

Pharmacological inhibition of the PI3K/PTEN/Akt and mTOR signalling pathways limits follicle activation induced by ovarian cryopreservation and in vitro culture

BACKGROUND

Cryopreservation and transplantation of ovarian tissue (OTCTP) represent a promising fertility preservation technique for prepubertal patients or for patients requiring urgent oncological management. However, a major obstacle of this technique is follicle loss due to, among others, accelerated recruitment of primordial follicles during the transplantation process, leading to follicular reserve loss in the graft and thereby potentially reducing its lifespan. This study aimed to assess how cryopreservation itself impacts follicle activation.

RESULTS

Western blot analysis of the PI3K/PTEN/Akt and mTOR signalling pathways showed that they were activated in mature or juvenile slow-frozen murine ovaries compared to control fresh ovaries. The use of pharmacological inhibitors of follicle signalling pathways during the cryopreservation process decreased cryopreservation-induced follicle recruitment. The second aim of this study was to use in vitro organotypic culture of cryopreserved ovaries and to test pharmacological inhibitors of the PI3K/PTEN/Akt and mTOR pathways. In vitro organotypic culture-induced activation of the PI3K/PTEN/Akt pathway is counteracted by cryopreservation with rapamycin and in vitro culture in the presence of LY294002. These results were confirmed by follicle density quantifications. Indeed, follicle development is affected by in vitro organotypic culture, and PI3K/PTEN/Akt and mTOR pharmacological inhibitors preserve primordial follicle reserve.

CONCLUSIONS

Our findings support the hypothesis that inhibitors of mTOR and PI3K might be an attractive tool to delay primordial follicle activation induced by cryopreservation and culture, thus preserving the ovarian reserve while retaining follicles in a functionally integrated state.

Immature Follicular Origins and Disrupted Oocyte Growth Pathways Contribute to Decreased Gamete Quality During Reproductive Juvenescence in Mice

Egg quality dictates fertility outcomes, and although there is a well-documented decline with advanced reproductive age, how it changes during puberty is less understood. Such knowledge is critical, since advances in Assisted Reproductive Technologies are enabling pre- and peri-pubertal patients to preserve fertility in the medical setting. Therefore, we investigated egg quality parameters in a mouse model of the pubertal transition or juvenescence (postnatal day; PND 11-40). Animal weight, vaginal opening, serum inhibin B levels, oocyte yield, oocyte diameter, and zona pellucida thickness increased with age. After PND 15, there was an age-associated ability of oocytes to resume meiosis and reach metaphase of meiosis II (MII) following in vitro maturation (IVM). However, eggs from the younger cohort (PND 16-20) had significantly more chromosome configuration abnormalities relative to the older cohorts and many were at telophase I instead of MII, indicative of a cell cycle delay. Oocytes from the youngest mouse cohorts originated from the smallest antral follicles with the fewest cumulus layers per oocyte, suggesting a more developmentally immature state. RNA Seq analysis of oocytes from mice at distinct ages revealed that the genes involved in cellular growth signaling pathways (PI3K, mTOR, and Hippo) were consistently repressed with meiotic competence, whereas genes involved in cellular communication were upregulated in oocytes with age. Taken together, these data demonstrate that gametes harvested during the pubertal transition have low meiotic maturation potential and derive from immature follicular origins.

Recent advances: fertility preservation and fertility restoration options for males and females

Fertility preservation is the process of saving gametes, embryos, gonadal tissues and/or gonadal cells for individuals who are at risk of infertility due to disease, medical treatments, age, genetics, or other circumstances. Adult patients have the options to preserve eggs, sperm, or embryos that can be used in the future to produce biologically related offspring with assisted reproductive technologies. These options are not available to all adults or to children who are not yet producing mature eggs or sperm. Gonadal cells/tissues have been frozen for several thousands of those patients worldwide with anticipation that new reproductive technologies will be available in the future. Therefore, the fertility preservation medical and research communities are obligated to responsibly develop next-generation reproductive technologies and translate them into clinical practice. We briefly describe standard options to preserve and restore fertility, but the emphasis of this review is on experimental options, including an assessment of readiness for translation to the human fertility clinic.

Live births following fertility preservation using in-vitro maturation of ovarian tissue oocytes

STUDY QUESTION

Can oocytes extracted from excised ovarian tissue and matured in vitro be a useful adjunct for urgent fertility preservation (FP)?

SUMMARY ANSWER

Ovarian tissue oocyte in-vitro maturation (OTO-IVM) in combination with ovarian tissue cryopreservation (OTC) is a valuable adjunct technique for FP.

WHAT IS KNOWN ALREADY

Despite the impressive progress in the field, options for FP for cancer patients are still limited and, depending on the technique, clinical outcome data are still scarce.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study conducted at a university hospital-affiliated fertility clinic between January 2012 and May 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study included 77 patients who underwent unilateral oophorectomy for OTC. Cumulus-oocyte complexes (COCs) obtained during ovarian tissue processing were matured in vitro for 28-42 h. Oocytes reaching metaphase II stage were vitrified or inseminated for embryo vitrification.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, 1220 COCs were collected. The mean oocyte maturation rate was 39% ± 23% (SD). There were 64 patients who had vitrification of oocytes (6.7 ± 6.3 oocytes per patient). There were 13 patients who had ICSI of mature oocytes after IVM, with 2.0 ± 2.0 embryos vitrified per patient. Twelve patients have returned to the clinic with a desire for pregnancy. For seven of these, OTO-IVM material was thawed. Two patients had OTO-IVM oocytes warmed, with survival rates of 86% and 60%. After ICSI, six oocytes were fertilised in total, generating three good quality embryos for transfer, leading to a healthy live birth for one patient. In five patients, for whom a mean of 2.0 ± 0.8 (SD) embryos had been vitrified, seven embryos were warmed in total: one embryo did not survive the warming process; two tested genetically unsuitable for transfer; and four were transferred in separate cycles to three different patients, resulting in two healthy babies. In this small series, the live birth rate per patient after OTO-IVM, ICSI and embryo transfer was 43%.

LIMITATIONS, REASONS FOR CAUTION

The retrospective study design and the limited sample size should be considered when interpreting results.

WIDER IMPLICATIONS OF THE FINDINGS

The results of the study illustrate the added value of OTO-IVM in combination with OTC. We report the first live birth following the use of this appended technique combined with oocyte vitrification.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. M.D.V. reports honoraria for lectures in the last 2 years from MSD and Ferring, outside the submitted work, as well as grant support from MSD. The other authors have nothing to declare.

TRIAL REGISTRATION NUMBER

N/A.

Recent Advancements in Engineered Biomaterials for the Regeneration of Female Reproductive Organs

Various gynecologic diseases and chemoradiation or surgery for the management of gynecologic malignancies may damage the uterus and ovaries, leading to clinical problems such as infertility or early menopause. Embryo or oocyte cryopreservation-the standard method for fertility preservation-is not a feasible option for patients who require urgent treatment because the procedure requires ovarian stimulation for at least several days. Hormone replacement therapy (HRT) for patients diagnosed with premature menopause is contraindicated for patients with estrogen-dependent tumors or a history of thrombosis. Furthermore, these methods cannot restore the function of the uterus and ovaries. Although autologous transplantation of cryopreserved ovarian tissue is being attempted, it may re-introduce malignant cells after cancer treatment. With the recent development in regenerative medicine, research on engineered biomaterials for the restoration of female reproductive organs is being actively conducted. The use of engineered biomaterials is a promising option in the field of reproductive medicine because it can overcome the limitations of current therapies. Here, we review the ideal properties of biomaterials for reproductive tissue engineering and the recent advancements in engineered biomaterials for the regeneration of female reproductive organs.

Purging human ovarian cortex of contaminating leukaemic cells by targeting the mitotic catastrophe signalling pathway

PURPOSE

Is it possible to eliminate metastasised chronic myeloid leukaemia (CML) and acute myeloid leukaemia (AML) cells from ovarian cortex fragments by inhibition of Aurora B/C kinases (AURKB/C) without compromising ovarian tissue or follicles?

METHODS

Human ovarian cortex tissue with experimentally induced tumour foci of CML, AML and primary cells of AML patients were exposed to a 24h treatment with 1 μM GSK1070916, an AURKB/C inhibitor, to eliminate malignant cells by invoking mitotic catastrophe. After treatment, the inhibitor was removed, followed by an additional culture period of 6 days to allow any remaining tumour cells to form new foci. Ovarian tissue integrity after treatment was analysed by four different assays. Appropriate controls were included in all experiments.

RESULTS

Foci of metastasised CML and AML cells in ovarian cortex tissue were severely affected by a 24h ex vivo treatment with an AURKB/C inhibitor, leading to the formation of multi-nuclear syncytia and large-scale apoptosis. Ovarian tissue morphology and viability was not compromised by the treatment, as no significant difference was observed regarding the percentage of morphologically normal follicles, follicular viability, glucose uptake or in vitro growth of small follicles between ovarian cortex treated with 1 μM GSK1070916 and the control.

CONCLUSION

Purging of CML/AML metastases in ovarian cortex is possible by targeting the Mitotic Catastrophe Signalling Pathway using GSK1070916 without affecting the ovarian tissue. This provides a therapeutic strategy to prevent reintroduction of leukaemia and enhances safety of autotransplantation in leukaemia patients currently considered at high risk for ovarian involvement.

Spectroscopic assessment of oxidative damage in biomolecules and tissues

Oxidative damage is one of the main causes of cryopreservation injury compromising the use of cryopreserved biospecimens. The aim of this study was to evaluate the use of Fourier transform infrared spectroscopy (FTIR) as a non-invasive method to assess changes in biomolecular composition and structure, associated with oxidative stress in isolated biomolecules, acellular heart valve tissues, and ovarian cortex tissues. FTIR spectra of these specimens subjected to various treatments (H₂O₂- and Fenton-treatment or elevated temperatures) were vector normalized and selected spectral regions were analyzed by principal component analysis (PCA). Control and damaged biomolecules can easily be separated using PCA score plots. Acellular heart valve tissues that were subjected to different levels of oxidative damage formed separate cluster in PCA score plots. In hydrated ovarian tissue, large variation of the principal components was observed. Drying the ovarian tissues samples resulted in improved cluster separation of treatment groups. However, early signs of oxidative damage under mild stress conditions could not be detected by PCA of FTIR spectra. For the ovarian tissue samples, the standardly used nitro blue tetrazolium chloride (NBT) assay was used to monitor the amount of formazan production, reflecting reactive oxygen species (ROS) production at various temperatures. At 37 °C, formazan staining rapidly increased during the first 30 min, and then slowly reached a saturation level, but also at lower temperatures (i.e. 4 °C) formazan production was observed. In summary, we conclude that ATR-FTIR combined with PCA can be used to study oxidative damage in biomolecules as well as in tissues. In tissues, however, sample heterogeneity makes it difficult to detect early signs of oxidative damage.

Fertility preservation for female patients with childhood, adolescent, and young adult cancer: recommendations from the PanCareLIFE Consortium and the International Late Effects of Childhood Cancer Guideline Harmonization Group

Female patients with childhood, adolescent, and young adult cancer are at increased risk for fertility impairment when treatment adversely affects the function of reproductive organs. Patients and their families desire biological children but substantial variations in clinical practice guidelines reduce consistent and timely implementation of effective interventions for fertility preservation across institutions. As part of the PanCareLIFE Consortium, and in collaboration with the International Late Effects of Childhood Cancer Guideline Harmonization Group, we reviewed the current literature and developed a clinical practice guideline for fertility preservation in female patients who were diagnosed with childhood, adolescent, and young adult cancer at age 25 years or younger, including guidance on risk assessment and available methods for fertility preservation. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to grade the available evidence and to form the recommendations. This clinical practice guideline leverages existing evidence and international expertise to develop transparent recommendations that are easy to use to facilitate the care of female patients with childhood, adolescent, and young adult cancer who are at high risk for fertility impairment. A complete review of the existing evidence, including a quality assessment, transparent reporting of the guideline panel's decisions, and achievement of global interdisciplinary consensus, is an important result of this intensive collaboration.

Fertility Preservation: The Challenge of Freezing and Transplanting Ovarian Tissue

Cancer treatments are increasingly effective, but can result in iatrogenic premature ovarian insufficiency. Ovarian tissue cryopreservation is the only option available to preserve fertility in prepubertal girls and young women who require immediate chemotherapy. Ovarian tissue transplantation has been shown to restore hormonal cycles and fertility, but a large proportion of the follicle reserve is lost as a consequence of exposure to hypoxia. Another crucial concern is the risk of reimplanting malignant cells together with the grafted tissue. In this review, the authors advance some challenging propositions, from prevention of chemotherapy-related gonadotoxicity to ovarian tissue cryopreservation and transplantation, including the artificial ovary approach.

Ovarian tissue cryopreservation and novel bioengineering approaches for fertility preservation

PURPOSE OF REVIEW

Breast cancer patients who cannot delay treatment or for whom hormone stimulation and egg retrieval are contraindicated require alternative methods of fertility preservation prior to gonadotoxic treatment. Ovarian tissue cryopreservation is an alternative approach that may offer patients the opportunity to preserve fertility and carry biologically-related children later in life. Various experimental approaches are being explored to obtain mature gametes from cryopreserved and thawed ovarian tissue for fertilization and implantation using biomimetic tissue culture in vitro. Here we review the most recent developments in ovarian tissue cryopreservation and exciting advances in bioengineering approaches to in vitro tissue and ovarian follicle culture.

RECENT FINDINGS

Slow freezing is the most widely accepted method for ovarian tissue cryopreservation, but efforts have been made to modify vitrification for this application as well. Numerous approaches to in vitro tissue and follicle culture are in development, most prominently two-step culture systems for ovarian cortical tissue and encapsulation of ovarian follicles in biomimetic matrices for in vitro culture.

SUMMARY

Refinements to slow freeze and vitrification protocols continue to address challenges associated with cryopreservation, such as ice crystal formation and damage to the stroma. Similarly, improvements to in vitro tissue and follicle culture show promise for utilizing patients' cryopreserved tissues to obtain mature gametes after disease treatment and remission. Development of an effective and reproducible culture system for human ovarian follicles will serve as a broad assisted reproductive technology for cancer survivors who cryopreserved tissue prior to treatment.

In-vitro fragmentation of ovarian tissue activates primordial follicles through the Hippo pathway

STUDY QUESTION

What is the role of the Hippo and PI3K/Akt pathway in follicles during ovarian tissue culture in tissue derived from oncological patients and transgender men?

SUMMARY ANSWER

Results highlight a Hippo pathway driven primordial follicle activation in vitro, predominantly from Day 0 to Day 4.

WHAT IS KNOWN ALREADY

In-vitro ovarian tissue culture aims at activating and maturing primordial follicles for fertility restoration in patients with a threatened ovarian reserve. Not all patients are eligible for ovarian cortex transplantation and therefore several groups are attempting to culture ovarian tissue in-vitro. Cortex fragmentation disrupts the Hippo pathway, leading to increased expression of downstream growth factors and follicle growth. The PI3K/Akt pathway is considered the intracellular pathway to where different extracellular factors involved in primordial follicle activation in-vivo converge. In order to optimise current ovarian tissue culture models, information on progression of these pathways during tissue culture is mandatory.

STUDY DESIGN SIZE DURATION

The first step of a multistep cortex culture system was performed using 144 ovarian cortex pieces from a total of six patients. Per patient, 24 cortical strips were cultured for 6 days and six pieces per patient were collected for downstream analysis of follicle development and Hippo and PI3K/Akt pathway targets every second day.

PARTICIPANTS/MATERIALS SETTING METHODS

Ovarian tissue was obtained from oncological (N = 3; 28.67 ± 4.51 years) and transgender (N = 3; 23.33 ± 1.53 years) patients. Follicles were analysed using haematoxylin-eosin staining and pathways were studied using immunohistochemistry and precise follicle excision by laser capture micro-dissection for RT-qPCR analysis. MIQE guidelines for RT-qPCR were pursued. Reference gene selection (GAPDH, RPL3A, 18s rRNA) was performed using GeNorm Reference Gene Selection Kit. Statistical analysis was conducted with IBM SPSS Statistics 23 (Poisson regression, negative binomial regression, ANOVA and paired t-test).

MAIN RESULTS AND THE ROLE OF CHANCE

Immunohistochemical analysis confirmed a Hippo pathway driven primordial follicle activation due to mechanical manipulation of the cortical strips. Ovarian tissue preparation and culture induced the inhibitory phosphorylated Yes-associated protein (pYAP) to disappear in granulosa cells of primordial follicles on Day 2. The stimulatory YAP on the contrary appeared in primordial granulosa cells over increasing culture days. Looking at the YAP target connective tissue growth factor (CTGF), a significantly up-regulated CTGF was noted in primordial follicles when comparing Day 2 and Day 4 (ratio Day 2/4 = 0.082; P < 0.05), clearly showing an effect on the Hippo pathway in primordial follicles during tissue culture. Follicle classification showed a significant drop in estimated primordial follicle counts in the oncological cohort (-78%; P = 0.021) on Day 2 and in the transgender cohort on Day 4 (-634%; P = 0.008). Intermediate follicle counts showed a non-significant increasing trend to during culture and this follicle recruitment and growth resulted in a significant rise in estimated primary follicle counts on Day 6 in oncological patients (170%; P = 0.025) and, although limited in absolute numbers, a significant increase in secondary follicles on Day 4 (367%; P = 0.021) in the transgender cohort. Subsequent antral follicle development could not be observed.

LIMITATIONS REASONS FOR CAUTION

A limitation is the small sample size, inherent to this study subject, especially as a large amount of tissue was needed per patient to reduce inter-patient variation in different downstream analysis techniques. A particular and specific weakness of this study is the inability to include an age-matched control group.

WIDER IMPLICATIONS OF THE FINDINGS

These findings support an adapted tissue preparation for Hippo pathway disruption and a shorter first phase of tissue culture. This work may also have implications for transplantation of cryopreserved tissue as larger strips (and thus slower burnout due to less Hippo pathway disruption) could be a benefit.

STUDY FUNDING/COMPETING INTERESTS

This research was financially supported by the Foundation Against Cancer (Stichting tegen Kanker, TBMT001816N), the Flemish Foundation of Scientific Research (FWO Vlaanderen, FWO G0.065.11N10) and the Gender Identity Research and Education Society (GIRES) foundation. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Preservation of connexin 43 and transzonal projections in isolated bovine pre-antral follicles before and following vitrification

PURPOSE

Gap junctions and transzonal projections play a crucial role in intercellular communication between different follicular components and are necessary for follicle development. We aimed to demonstrate gap junction protein connexin 43 (Cx43) and transzonal projections (TZPs) in viable, category 1, isolated bovine pre-antral follicles (PAFs) during short-term culture and after vitrification and warming.

METHODS

This study involved four experimental groups: fresh control, 2-day culture, 4-day culture, and vitrified secondary PAFs. Isolated PAFs were vitrified using a simple and efficient cryopreservation method by means of mini cell strainers.

RESULTS

Cx43 and TZPs were detected in pre-antral follicles of all stages, as well as in every experimental group. The group fresh follicles showed a higher percentage of follicles that were positive for Cx43 (91.7%) than the follicles that were vitrified (77.4%). All follicles that were cultured for 2 days were Cx43-positive (100%). Follicles cultured for 4 days (65.8%) (P = 0.002) showed the lowest percentage of follicles that were Cx43-positive. The percentages of the presence or (partial) absence of the TZP network were shown to be very heterogeneous between follicles in different treatment groups.

CONCLUSIONS

These results suggest the maintenance of communication between the oocyte and the somatic companion cells after vitrification and warming. The varying percentages of the expression of the TZP network within groups suggests that it will be of interest to investigate whether this is truly due to variability in TZP integrity and follicle quality or due to methodological limitations.

Preservation of fertility in female: Indications, available options, and current status in Saudi Arabia

Refinement of therapies continues to improve the prognosis and survival of cancer patients. However, women of reproductive age face a risk of premature ovarian failure due to the gonadotoxicity of aggressive oncological treatment, which may also be used to treat other nonmalignant disorders. Development of cryobiology and assisted reproduction has allowed fertility preservation, which is increasingly requested, and can also aid fertility in iatrogenic and noniatrogenic conditions. Established protocols including embryo and oocyte freezing are only performed for adult women; however, ovarian tissue cryopreservation is an approach that can also assist prepubertal girls. Medical fertility cryopreservation for females has been recently legalized in Saudi Arabia. However, prior to implementing the service in clinical practice in Saudi Arabia, guidelines on patient selection criteria and adequate staff training are essential. Moreover, worldwide registry data and the findings of long-term studies involving many patients on the safety of ovarian tissue freezing are required to conclusively establish medical fertility cryopreservation as a safe procedure. Progress can be achieved in oncofertility by improving and optimizing techniques that include immature oocyte growth and maturation and artificial ovary development.