Ovarian tissue transport to expand access to fertility preservation: from animals to clinical practice

Comparison of liquid nitrogen-free slow freezing protocols toward enabling a practical option for centralized cryobanking of ovarian tissue

Geographically distributed ovarian tissue cryobanks remain limited due to the high facility and staff costs, and cold transportation to centers is associated with ischemia-induced tissue damage that increases with transport distance. It is ideal to perform the cryopreservation procedure at a tissue removal site or local hospital before shipment to cost-effective centralized cryobanks. However, conventional liquid nitrogen-based freezers are not portable and require expensive infrastructure. To study the possibility of an ovarian tissue cryopreservation network not dependent on liquid nitrogen, we cryopreserved bovine ovarian tissue using three cooling techniques: a controlled rate freezer using liquid nitrogen, a liquid nitrogen-free controlled rate freezer, and liquid nitrogen-free passive cooling. Upon thawing, we evaluated a panel of viability metrics in frozen and fresh groups to examine the potency of the portable liquid nitrogen-free controlled and uncontrolled rate freezers in preserving the ovarian tissue compared to the non-portable conventional controlled rate freezer. We found similar outcomes for reactive oxygen species (ROS), total antioxidant capacity (TAC), follicular morphology, tissue viability, and fibrosis in the controlled rate freezer groups. However, passive slow cooling was associated with the lowest tissue viability, follicle morphology, and TAC, and the highest tissue fibrosis and ROS levels compared to all other groups. A stronger correlation was found between follicle morphology, ovarian tissue viability, and fibrosis with the TAC/ROS ratio compared to ROS and TAC alone. The current study undergirds the possibility of centralized cryobanks using a controlled rate liquid nitrogen-free freezer to prevent ischemia-induced damage during ovarian tissue shipment.

Improvement of Mouse Preantral Follicle Survival and Development following Co-Culture with Ovarian Parenchyma Cell Suspension

BACKGROUND

The parallel and continued improvements in both infertility treatment and the management of malignancy cases have brought to the forefront the potential for fertility preservation. Using ovarian follicular resources can effectively improve reproductive capacity and prevent infertility. The primary aim of this research was to try to generate an appropriate in vivo environment for the growth of the mouse follicles. Hence, the possible effects of the ovarian parenchyma cell suspension were explored on the growth and maturation of preantral follicles in vitro.

MATERIALS AND METHODS

In this experimental study, ovarian parenchymal cells were mechanically dissociated from preantral follicles of 12-14 days-old NMRI mice and then divided into 5 experimental groups (G1: Control, G2: Fresh follicle with fresh parenchyma cell suspension, G3: Vitrified-warmed follicle with fresh parenchyma cell suspension, G4: Fresh follicle with frozen-thawed parenchyma cell suspension, and G5: Vitrified-warmed follicle with frozenthawed parenchyma cell suspension). The diameter of the follicles and immature oocytes, viability, antrum formation, resumption of meiosis, in vitro fertilization (IVF), and Gdf9, Bmp6, and Bmp15 gene expression were examined on different periods.

RESULTS

The diameter of the follicles and the oocytes on days 4 and 8, as well as the survival rate of the follicles up to day 12, were significantly higher in G2 and G4 compared to the Ctrl group (G1: 73.66%, G2:87.99%, G3: 82.70%, G4: 94.37%, and G5: 78.59%). Expression of growth marker genes for G3, and G5 groups was significantly higher than other groups, which indicated the protective effects of parenchyma cell suspension on follicles damaged by vitrification solutions.

CONCLUSION

The growth, survival, and maturation of preantral follicles could be enhanced by co-culturing them with ovarian parenchyma cells. Further studies are needed to optimize the conditions for a successful parenchyma cell suspension-induced in vitro maturation (IVM) to occur in infertility clinics.

Effects of bovine ovarian storage conditions and vitrification on isolated preantral follicle viability

Graphical abstract

Lay summary

The decreasing rate of successful pregnancies, both naturally and through assisted conception, has led to innovations in the way eggs, sperm, and embryos are stored. Despite these advances, the use of assisted reproductive techniques to preserve endangered or rare species remains unexplored. Since the location where samples are collected and facilities are often far apart, we aim to address part of this challenge by comparing different methods to store and handle ovarian tissue before freezing. This may pave the way for further research in preserving endangered species, despite the challenges posed by the distance between sample collection sites and suitable facilities.

IVM Advances for Early Antral Follicle-Enclosed Oocytes Coupling Reproductive Tissue Engineering to Inductive Influences of Human Chorionic Gonadotropin and Ovarian Surface Epithelium Coculture

In vitro maturation (IVM) is not a routine assisted reproductive technology (ART) for oocytes collected from early antral (EA) follicles, a large source of potentially available gametes. Despite substantial improvements in IVM in the past decade, the outcomes remain low for EA-derived oocytes due to their reduced developmental competences. To optimize IVM for ovine EA-derived oocytes, a three-dimensional (3D) scaffold-mediated follicle-enclosed oocytes (FEO) system was compared with a validated cumulus-oocyte complex (COC) protocol. Gonadotropin stimulation (eCG and/or hCG) and/or somatic cell coculture (ovarian vs. extraovarian-cell source) were supplied to both systems. The maturation rate and parthenogenetic activation were significantly improved by combining hCG stimulation with ovarian surface epithelium (OSE) cells coculture exclusively on the FEO system. Based on the data, the paracrine factors released specifically from OSE enhanced the hCG-triggering of oocyte maturation mechanisms by acting through the mural compartment (positive effect on FEO and not on COC) by stimulating the EGFR signaling. Overall, the FEO system performed on a developed reproductive scaffold proved feasible and reliable in promoting a synergic cytoplasmatic and nuclear maturation, offering a novel cultural strategy to widen the availability of mature gametes for ART.

National Ovarian and Testicular Tissue Transport and Cryopreservation Service (NOTTCS)

Background: Recognised female fertility preservation strategies include oocyte and embryo cryopreservation. Ovarian tissue cryopreservation is no longer experimental, and the only option for children and pre-pubertal girls. Although testicular cryopreservation remains experimental for boys, it has the potential to evolve and provide a realistic opportunity for fertility in the future. The RWH/MIVF fertility preservation service has been preserving ovarian tissue since 1995. This service has been available to children, adolescent young adults (AYA) and adults about to receive gonadotoxic treatment for malignant and non-malignant conditions. In 2013, this service was extended to freezing testicular tissue for pre-pubertal and peri-pubertal males. Until 2019 these fertility preservation options have only been available to those undergoing procedures at Melbourne metropolitan hospitals. Young cancer patients seeking fertility preservation in regional or interstate areas, did not have this opportunity due to lack of access and resources. One approach to increasing patient access to Gonadal Tissue Cryopreservation (GTC), was to establish a national tissue retrieval and transport service.

Aim: This paper describes the uptake of a GTC transport program at RWH, allowing rural and interstate oncology referral for transport, processing and storage of gonadal tissue in an acknowledged centre of excellence.

Method: An information/education/instruction resource package was developed for fertility units Australia-wide, supported by a centralised GTC program coordinator. Referrals are fast tracked to eliminate any delay in treatment. Gonadal tissue is harvested at the referring hospital and transported to RWH for cryopreservation and storage, following methods established in other countries with a centralised service 1 – 3 .

Results: To date, 40 ovarian and testicular tissue has been transported from all Australian states, and Northern Territory to RWH, including semen transported from a regional hospital where no fertility service was available. This service was made possible, and free of charge to those patients 13–30 yo with a cancer diagnosis, through a generous donation by Sony Foundation.

Conclusion: Provision of a comprehensive fertility preservation service, including GTC, for young people, was not widely available until 2019. Gonadal tissue transport facilitates engagement and upskilling in oncofertility with extensive support from a centre of excellence, allowing expansion of patient and provider access to best-practice fertility preservation options, regardless of their geographic location and socio-economic status.

Human Ovarian Follicles Xenografted in Immunoisolating Capsules Survive Long Term Implantation in Mice

Female pediatric cancer survivors often develop Premature Ovarian Insufficiency (POI) owing to gonadotoxic effects of anticancer treatments. Here we investigate the use of a cell-based therapy consisting of human ovarian cortex encapsulated in a poly-ethylene glycol (PEG)-based hydrogel that replicates the physiological cyclic and pulsatile hormonal patterns of healthy reproductive-aged women. Human ovarian tissue from four donors was analyzed for follicle density, with averages ranging between 360 and 4414 follicles/mm3. Follicles in the encapsulated and implanted cryopreserved human ovarian tissues survived up to three months, with average follicle densities ranging between 2 and 89 follicles/mm3 at retrieval. We conclude that encapsulation of human ovarian cortex in PEG-based hydrogels did not decrease follicle survival after implantation in mice and was similar to non-encapsulated grafts. Furthermore, this approach offers the means to replace the endocrine function of the ovary tissue in patients with POI.

High cryo-resistance of SARS-CoV-2 virus: Increased risk of re-contamination at transplantation of cryopreserved ovarian tissue after COVID-19 pandemic

Cryopreservation and re-transplantation of ovarian tissue after anticancer treatment is important medical technology. Today, during a pandemic, the risk of contamination of transplanted cells with SARS-CoV-2 virus is extremely high. Data about cryo-resistance (virulence and/or infectivity) of SARS-CoV-2 are limited. Analysis and systematization of literature data allow us to draw the following conclusions: 1) The cytoplasmic membrane of somatic cell, like envelope of corona viruses, consists of lipid bilayer and this membrane, like envelope of corona virus, contains membrane proteins. Thus, we can consider the cytoplasmic membrane of an ordinary somatic cell as a model of the envelope membrane of SARS-CoV-2. It is expected that the response of the virus to cryopreservation is similar to that of a somatic cell. SARS-CoV-2 is more poor-water and more protein-rich than somatic cell, and this virus is much more cryo-resistant. 2) The exposure of somatic cells at low positive temperatures increases a viability of these cells. The safety of the virus is also in direct proportion to the decrease in temperature: the positive effect of low temperatures on SARS-CoV-2 virus has been experimentally proven. 3) Resistance of SARS-CoV-2 to cryoprotectant-free cryopreservation is extremely high. The high viability rate of SARS-CoV-2 after freezing-drying confirms its high cryo-resistance. 4) The risk of SARS-CoV-2 infection after transplantation of cryopreserved ovarian tissues that have been contaminated with this virus, increases significantly. Our own experimental data on the increase in the viability of cancer cells after cryopreservation allow us to formulate a hypothesis about increasing of viability (virulence and/or infectivity) of SARS-CoV-2 virus after cryopreservation.

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.

Long-time low-temperature transportation of human ovarian tissue before cryopreservation

RESEARCH QUESTION

Can the low-temperature transport time of removed human ovarian tissue be prolonged until cryopreservation?

DESIGN

Fresh ovarian cortex from nine premenopausal patients was either slow-frozen immediately or stored at 4°C for 24 or 48 h before slow-freezing. The fresh and frozen-thawed biopsies were evaluated by follicle counting via calcein staining, histologic analyses via haematoxylin and eosin staining, and apoptosis via terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling (TUNEL). The fresh cortex was assessed by reactive oxygen species (ROS) and total antioxidant capacity (TAC) assay to detect oxidative stress. The frozen-thawed cortex biopsies were also evaluated by quantitative PCR for messenger RNA (mRNA) expression of BCL-2, BAX, TNFa, HIF-1a, BMP15 and GDF9, and Western blot for detection of BCL-2, BMP15, GDF9 and CASPASE-3. The frozen-thawed cortex was cultured in vitro for 4 days, anti-Müllerian hormone and glucose were assessed in the supernatant, and ROS and TAC assay detected any oxidative stress in the cortex.

RESULTS

In the fresh cortex, there were no significant differences between the three groups. In the frozen-thawed cortex, there were no significant differences between the three groups regarding follicle viability, TUNEL, mRNA expression of TNFa, HIF-1a or BMP15. GDF9 mRNA and BAX/BCL-2 were lower and higher at 48 h than at 0 h, respectively. However, the protein expression of BCL-2, CASPASE-3, GDF9 and BMP15 were no different. In the cultured cortex, ROS, TAC and glucose uptake were no different across the three groups.

CONCLUSION

Ovarian tissue transportation was validated for 24 h in the procedure used in clinical practice. This study showed that 4-8°C transportation for 24 or 48 h does not seem to damage the ovarian tissue. However, ovarian tissue transportation beyond 48 h needs to be further studied for conclusions to be made.

A View from the past into our collective future: the oncofertility consortium vision statement

Purpose

Today, male and female adult and pediatric cancer patients, individuals transitioning between gender identities, and other individuals facing health extending but fertility limiting treatments can look forward to a fertile future. This is, in part, due to the work of members associated with the Oncofertility Consortium.

Methods

The Oncofertility Consortium is an international, interdisciplinary initiative originally designed to explore the urgent unmet need associated with the reproductive future of cancer survivors. As the strategies for fertility management were invented, developed or applied, the individuals for who the program offered hope, similarly expanded. As a community of practice, Consortium participants share information in an open and rapid manner to addresses the complex health care and quality-of-life issues of cancer, transgender and other patients. To ensure that the organization remains contemporary to the needs of the community, the field designed a fully inclusive mechanism for strategic planning and here present the findings of this process.

Results

This interprofessional network of medical specialists, scientists, and scholars in the law, medical ethics, religious studies and other disciplines associated with human interventions, explore the relationships between health, disease, survivorship, treatment, gender and reproductive longevity.

Conclusion

The goals are to continually integrate the best science in the service of the needs of patients and build a community of care that is ready for the challenges of the field in the future.

The Effects of Negative Elements in Environment and Cancer on Female Reproductive System

With the development of human society, factors that contribute to the impairment of female fertility is accumulating. Lifestyle-related risk factors, occupational risk factors, and iatrogenic factors, including cancer and anti-cancer treatments, have been recognized with their negative effects on the function of female reproductive system. However, the exact influences and their possible mechanism have not been elucidated yet. It is impossible to accurately estimate the indexes of female fertility, but many researchers have put forward that the general fertility has inclined through the past decades. Thus the demand for fertility preservation has increased more and more dramatically. Here we described some of the factors which may influence female reproductive system and methods for fertility preservation in response to female infertility.

Is Ovarian Tissue Transport at Supra-zero Temperatures Compared to Body Temperature Optimal for Follicle Survival?

BACKGROUND/AIM

Transportation of ovarian cortex prior to freezing is used clinically; however, basic investigations of ovarian storage are limited and the question remains what temperature is optimal for transport over long distances and time periods. The aim of this study was to evaluate the rate of follicular loss over various time periods under two different temperatures and assess whether ovarian follicle viability is affected following cryopreservation and thawing subsequent to the transportation of ovarian tissue.

MATERIALS AND METHODS

Pig ovaries were transported at 4°C (n=10) or at 38°C (n=10) prior to cryopreservation. At 0, 4, 12 and 24 h tissues were fixed for histological examination and a LIVE/DEAD Assay. At the same time-points ovarian tissues were cryopreserved and analysed after thawing.

RESULTS

Histological evaluation and LIVE/DEAD Assay of freshly transported ovarian tissue showed significantly better follicle survival at 4°C during transportation duration. In cryopreserved ovarian tissues the LIVE/DEAD Assay showed a significant difference in the number of intact and dead follicles at 24 h in favor of 4°C (p<0.05).

CONCLUSION

Ovarian tissue transportation should be kept at a minimum to prevent potential damage.

Ovarian tissue transportation: a systematic review

In recent years, some countries and fertility preservation networks have started adopting 24 h transportation for ovarian tissue, a practice that has the potential to spread very quickly due to the high costs and bureaucracy involved in the establishment of ovarian tissue cryobanks. While pregnancies and live births have been reported after such long periods of transportation, this, however, remains an empirical procedure. This review aims to prompt reflection on ovarian tissue transport, highlighting the lack of knowledge in humans by providing a counterpoint looking into more than 40 studies published in different animal models. By discussing these studies in animals, the findings of various models can be deciphered, and light shed on the patterns identified. Like the development of different assisted reproductive technology procedures, this is an important step in creating guidelines for future studies on human ovarian tissue transportation.

Ovary cold storage and shipment affect oocyte yield and cleavage rate of cat immature vitrified oocytes

In feline species, cooled transport of ovaries can be employed without detrimental effects to retrieve immature oocytes intended for in vitro embryo production purposes. Indeed, this is the most common way to collect gametes from gonads of wild, valuable animals after they die or are castrated far from specialized laboratories. However, fresh retrieved gametes are generally used, and their cryosensitivity is not known. This study employed ovariectomy-derived domestic cat gonads as a model for wild felids, and aimed to compare the yield and developmental competence of Cryotop-vitrified oocytes (VOs) collected and cryopreserved right after ovary excision (In loco-VOs) or after 24 h cooled transport of ovaries (Shipped-VOs). The number of collected oocytes was higher in In loco-VOs than in Shipped-VOs (mean ± SD: 8 ± 3.36 vs 5.6 ± 3.1, p = 0.05). In vitro embryo production resulted in similar maturation (35% for both vitrified groups, p = 1) and fertilization rates (In loco-VOs: 29.1%; Shipped-VOs: 22.2%; p = 0.295), but showed a difference in cleavage (In loco-VOs: 25.6%; Shipped-VOs: 14.5%; p = 0.0495). No differences were found in further embryo development. Taken together, results suggested that delayed oocyte vitrification after cooled transport of organs was feasible and allowed embryo development. However, the number of collected oocytes and the cleavage rate of matured oocytes were higher when oocyte vitrification was performed without delay after ovary excision, and this should be considered in gamete conservation programs for endangered felids.

Heterotopic autotransplantation of ovarian tissue in a large animal model: Effects of cooling and VEGF

Heterotopic and orthotopic ovarian tissue autotransplantation techniques, currently used in humans, will become promising alternative methods for fertility preservation in domestic and wild animals. Thus, this study describes for the first time the efficiency of a heterotopic ovarian tissue autotransplantation technique in a large livestock species (i.e., horses) after ovarian fragments were exposed or not to a cooling process (4°C/24 h) and/or VEGF before grafting. Ovarian fragments were collected in vivo via an ultrasound-guided biopsy pick-up method and surgically autografted in a subcutaneous site in both sides of the neck in each mare. The blood flow perfusion at the transplantation site was monitored at days 2, 4, 6, and 7 post-grafting using color-Doppler ultrasonography. Ovarian grafts were recovered 7 days post-transplantation and subjected to histological analyses. The exposure of the ovarian fragments to VEGF before grafting was not beneficial to the quality of the tissue; however, the cooling process of the fragments reduced the acute hyperemia post-grafting. Cooled grafts compared with non-cooled grafts contained similar values for normal and developing preantral follicles, vessel density, and stromal cell apoptosis; lower collagen type III fibers and follicular density; and higher stromal cell density, AgNOR, and collagen type I fibers. In conclusion, VEGF exposure before autotransplantation did not improve the quality of grafted tissues. However, cooling ovarian tissue for at least 24 h before grafting can be beneficial because satisfactory rates of follicle survival and development, stromal cell survival and proliferation, as well as vessel density, were obtained.

Evidence of metabolic activity during low-temperature ovarian tissue preservation in different media

PURPOSE

Although ovarian tissue transportation has been validated for up to 24 h, there is no standard protocol to date. We aimed to elucidate how existing media currently used for ovarian tissue transportation affect ovarian tissue metabolism and cell viability.

METHODS

Cow ovarian fragments were immersed in 0.9% NaCl solution, IVF medium, Leibovitz 15 medium (L-15), or PBS for 1, 4, or 24 h at 4 °C. Media were analyzed for pH, lactate dehydrogenase (LDH) activity, and glucose, pyruvate, and lactate concentrations, while apoptosis was assessed by TUNEL assays in fixed fragments. Viability rates were assessed by flow cytometry (FACS).

RESULTS

There were lower pH levels in NaCl at all time points compared with other media. LDH activity increased with time and was lowest in NaCl at 1 and 4 h. There was no significant difference in glucose levels, but a significant pyruvate decrease in L-15 and a significant lactate increase in all media. TUNEL showed apoptosis rates ranging from 0 to 5%. FACS showed a mean of 4% necrotic cells and 15-19% apoptotic cells after 1 h of incubation, but less than 1% necrotic cells and 2-6% apoptotic cells after 24 h in all media.

CONCLUSION

Our results indicate marked metabolic activity in ovarian tissue at 4 °C and suggest that cells use internal sources of energy, which may influence transplantation outcomes. This highlights the importance of better understanding whole tissue dynamics to develop a standard protocol for ovarian tissue transportation. Graphical abstract.

Ovarian Histopathology in Transmasculine Persons on Testosterone: A Multicenter Case Series

BACKGROUND

As transmasculine persons utilize androgen gender affirming hormone therapy as a part of transition, guidance has been lacking on the effects of the therapy on the ovaries, especially for those who may desire retention.

AIM

To describe the ovarian histopathology of transmasculine persons on testosterone therapy following oophorectomy at the time of hysterectomy performed for gender affirmation.

METHODS

This was a multicenter case series study of transmasculine patients on testosterone therapy who underwent hysterectomy with oophorectomy for gender affirmation between January 2015 and December 2017 at 5 tertiary care referral centers. Patients were identified by their current procedural and International Classification of Diseases codes.

OUTCOMES

Pre-, perioperative, and pathologic data were obtained from the electronic medical records and ovarian tissue descriptions from pathology reports were grouped into the following classifications: (i) simple/follicular cysts; (ii) polycystic ovaries; (iii) complex cysts; (iv) endometriomas; (v) other masses; (vi) atrophy; and (vii) normal.

RESULTS

85 patients were included in the study. At the time of oophorectomy, the mean age and body mass index of the cohort were 30.4 ± 8.4 years and 30.2 ± 7.3 kg/m², respectively, and the average interval from the initiation of testosterone to oophorectomy was 36 0.3 ± 37.9 months. On examination of ovarian histopathology, 49.4% (42) of specimens were found to have follicular/simple cysts, 5.9% (5) were polycystic, and 38.8% (33) had normal pathology. For those specimens with volume documented (n = 41), the median volume was 9.6 (range 1.5-82.5) cm³. There was no association between the duration of testosterone therapy or body mass index and the presence of cysts in the ovaries.

CLINICAL IMPLICATIONS

The results of this study reported benign histopathology in ovaries of a large cohort of transmasculine persons on testosterone which should be included when counseling patients on ovarian retention, as transmasculine patients may choose to retain their ovaries while on testosterone for a variety of reasons (including no desire to undergo surgery, desire for backup sex steroids, and potential use for future fertility).

STRENGTHS & LIMITATIONS

This is a large multicenter study seeking to address the uncertainty in present counseling surrounding ovarian conservation in transmasculine persons on testosterone therapy. Its limitations included its retrospective nature and inability to address ovarian function after testosterone discontinuance.

CONCLUSION

In this cohort of transmasculine patients on testosterone therapy undergoing hysterectomy with oophorectomy for gender affirmation, ovarian histopathology was benign in all the specimens. Grimstad FW, Fowler KG, New EP, et al. Ovarian Histopathology in Transmasculine Persons on Testosterone: A Multicenter Case Series. J Sex Med 2020;17:1807-1818.

Spatial Analysis of Growing Follicles in the Human Ovary to Inform Tissue Engineering Strategies

Cancer survivorship has increased considerably, but common cancer treatments may threaten female reproductive health and fertility. In females, standard fertility preservation techniques include egg and embryo banking and ovarian tissue cryopreservation, but these methods are not suitable for all individuals. Emerging fertility preservation technologies include in vitro follicle growth and ovarian bioprosthetics. Although these platforms hold tremendous promise, they remain in the preclinical phase likely because of our inability to adequately phenocopy the complexity of the in vivo ovarian environment. The goal of this study was to use an established research archive of fixed human ovarian tissue established through the Oncofertility Consortium to better understand the dynamics and milieu of growing follicles within the human ovary. We performed a histological analysis of the immediate surroundings of primary and secondary stage follicles. We evaluated oocyte and follicle diameters of these growing follicles, analyzed their growth trajectories, and mapped their precise relationships to other stage follicles within a defined area. We also stratified our findings according to participant age and previous treatment history. Our results serve as in vivo benchmarks for follicles grown in vitro and provide insight into how follicles should be seeded spatially within bioprosthetic ovaries, potentially improving the efficacy and clinical translation of these emerging technologies. Impact statement Life-preserving cancer treatments have greatly increased survivorship. However, treatments often have off-target health consequences that threaten female reproductive health and fertility. Although several standard fertility preservation options exist, there is a constant need to explore and expand options for all populations. In vitro follicle growth and ovarian bioprosthetics are new experimental procedures, which are currently limited to proof of concept. In this study, we analyzed human ovarian tissue from a deidentified biospecimen repository to characterize the growing follicle landscape with the ultimate goal of informing bioengineering practices. This spatial analysis pinpoints the geometry of growing follicles within the human ovary and provides a framework for paralleling this environment in ex vivo platforms.

Ultrasound Shear Wave Velocity Varies Across Anatomical Region in Ex Vivo Bovine Ovaries

The physical properties of the ovarian extracellular matrix (ECM) regulate the function of ovarian cells, specifically the ability of the ovary to maintain a quiescent primordial follicle pool while allowing a subset of follicles to grow and mature in the estrous cycle. Design of a long-term, cycling artificial ovary has been hindered by the limited information regarding the mechanical properties of the ovary. In particular, differences in the mechanical properties of the two ovarian compartments, the cortex and medulla, have never been quantified. Shear wave (SW) ultrasound elastography is an imaging modality that enables assessment of material properties, such as the mechanical properties, based on the velocity of SWs, and visualization of internal anatomy, when coupled with B-mode ultrasound. We used SW ultrasound elastography to assess whole, ex vivo bovine ovaries. We demonstrated, for the first time, a difference in mechanical properties, as inferred from SW velocity, between the cortex and medulla, as measured along the length (cortex: 2.57 ± 0.53 m/s, medulla: 2.87 ± 0.77 m/s, p < 0.0001) and width (cortex: 2.99 ± 0.81 m/s, medulla: 3.24 ± 0.97 m/s, p < 0.05) and that the spatial distribution and magnitude of SW velocity vary between these two anatomical planes. This work contributes to a larger body of literature assessing the mechanical properties of the ovary and related cells and specialized ECMs and will enable the rational design of biomimetic tissue engineered models and durable bioprostheses. Impact Statement Shear wave (SW) ultrasound elastography can be used to simultaneously assess the material properties and tissue structures when accompanied with B-mode ultrasound. We report a quantitative difference in mechanical properties, as inferred from SW velocity, between the cortex and medulla, with SW velocity being 11.4% and 8.4% higher in the medulla than the cortex when measured along the length and width, respectively. This investigation into the spatial and temporal variation in SW velocity in bovine ovaries will encourage and improve design of more biomimetic scaffolds for ovarian tissue engineering.

A fertility preservation toolkit for pediatric surgeons caring for children with cancer

Survival for children with cancer has improved significantly in recent decades, prompting an increasing emphasis on minimizing late effects of therapy, including infertility and premature gonadal insufficiency. The time interval after diagnosis and before therapy initiation can be stressful and overwhelming for patients and their families coming to terms with the implications of the diagnosis, but is also the optimal time to address oncofertility options. Pediatric surgeons are often an integral part of the care team for these patients during this vulnerable time period and play a key role in advocating for and performing oncofertility procedures. Children with cancer have both non-experimental and experimental fertility preservation options available depending on their pubertal status and a risk assessment performed based on their anticipated therapy. This review provides an oncofertility toolkit for pediatric surgeons to perform a risk assessment, counsel families on fertility preservation options, and establish an oncofertility program tailored to the resources available at their institutions.

FertiPROTEKT, Oncofertility Consortium and the Danish Fertility-Preservation Networks - What Can We Learn From Their Experiences?

Fertility preservation is an increasingly important discipline. It requires close coordination between reproductive medicine specialists, reproductive biologists, and oncologists in various disciplines. In addition, it represents a particular health policy challenge, since fertility-protection measures are to be understood as a treatment for side effects of gonadotoxic treatments and would therefore normally have to be reimbursed by health insurance companies. Therefore, it is inevitable that fertility-preservation activities should organise themselves into a network structure both as a medical-logistic network and as a professional medical society. The necessary network structures can differ significantly at regional, national, and international level, as the size of the regions to be integrated and the local cultural and geographical conditions, as well as the political conditions are very different. To address these issues, the current review aims to point out the basic importance and the chances but also the difficulties of fertility-protection networks and give practical guidance for the development of such network structures. We will not only discuss network structures theoretically but also present them based on three established, different sized networks, such as the Danish Network (www.rigshospitalet.dk), representing a centralised network in a small country; the German-Austrian-Swiss network FertiPROTEKT® (www.fertiprotekt.com), representing a centralised as well as decentralised network in a large country; and the Oncofertility® Consortium (www.oncofertility.northwestern.edu), representing a decentralised, internationally oriented network, primarily serving the transfer of knowledge among its members.

Overnight ovarian tissue transportation for centralized cryobanking: a feasible option

RESEARCH QUESTION

Is overnight transportation of ovarian tissue before cryopreservation in a centralized cryobank from the FertiPROTEKT network feasible?

DESIGN

Data from 1810 women with cryopreserved ovarian tissue after overnight transportation from December 2000 to December 2017 were analysed with a focus on transportation, tissue activity parameters and pregnancy, and delivery rates after transplantation.

RESULTS

A total of 92.4% of tissue samples arrived at ideal temperatures of 2-8°C, 0.4% were transported at temperatures lower than ideal and 6.4% were transported at temperatures that were too high, generally due to mishandling of the inlayed cool packs of the transportation boxes. In 62 women, 78 tissue transplantations were carried out. A subgroup of 30 women who underwent a single orthotopic transplantation with fulfilled criteria of a complete follow-up after transplantation until the end of study, a premature ovarian insufficiency after gonadotoxic therapy as well as the absence of pelvic radiation, was further analysed. In this group, transplantations into a peritoneal pocket accounted for 90%. Transplants were still active at 1 year and above after transplantation in 93.3%. Pregnancy and delivery rates were 46.7% and 43.3%, respectively, with one ongoing pregnancy at the end of the study.

CONCLUSIONS

Overnight transportation for central cryobanking is a feasible concept that results in high reproducible success rates through standardized professional tissue freezing and storage.

Immuno-Isolating Dual Poly(ethylene glycol) Capsule Prevents Cancer Cells from Spreading Following Mouse Ovarian Tissue Auto-Transplantation

For female cancer survivors, premature ovarian insufficiency (POI) is a common complication of anticancer treatments. Ovarian tissue cryopreservation before treatment, followed by auto-transplantation after remission is a promising option to restore fertility and ovarian endocrine function. However, auto-transplantation is associated with the risk of re-introducing malignant cells harbored in the stroma of the ovarian autograft. To mitigate this risk, we investigated in this pilot study whether an immuno-isolating dual-layered poly(ethylene glycol)(PEG) capsule can retain cancer cells, while supporting folliculogenesis. The dual PEG capsule loaded with 1000 4T1 cancer cells retained 100% of the encapsulated cells in vitro for 21 days of culture. However, a greater cell load of 10,000 cells/capsule led to capsule failure and cells’ release. To assess the ability of the capsule to retain cancer cells, prevent metastasis, and support folliculogenesis in vivo we co-encapsulated cancer cells with ovarian tissue in the dual PEG capsule and implanted subcutaneously in mice. Control mice implanted with 2000 non-encapsulated cancer cells had tumors formed within 14 days and metastasis to the lungs. In contrast, no tumor mass formation or metastasis to the lungs was observed in mice with the same number of cancer cells encapsulated in the capsule. Our findings suggest that the immuno-isolating capsule may prevent the escape of the malignant cells potentially harbored in ovarian allografts and, in the future, improve the safety of ovarian tissue auto-transplantation in female cancer survivors.

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.

Structure of preantral follicles, oxidative status and developmental competence of in vitro matured oocytes after ovary storage at 4 °C in the domestic cat model

BACKGROUND

Storage conditions during transportation of explanted ovaries are a critical step in setting up fertility preservation protocols in both animal and human fields. Here, we evaluated the effects of ovary storage at 4 °C on the preservation of preantral follicles and oocytes retrieved from antral follicles using the domestic cat as model.

METHODS

Ovaries were harvested from fifty-five healthy domestic queens during ovariectomy and stored at 4 °C for 0 (control), 24, 48, 72 and 96 h. In Experiment 1, the effects of the storage period at 4 °C on the morphology, cytoskeleton (α/β tubulin) and DNA integrity (phosphorylation of histone H2AX) of preantral follicles were investigated. In Experiment 2, oocytes recovered from antral follicles were matured and fertilized in vitro to evaluate their meiotic and developmental competence. Reactive oxygen species (ROS), glutathione (GSH) and lipid peroxidation were measured in matured oocytes.

RESULTS

The results showed that: a) storage up to 24 h did not affect the morphology and the DNA integrity of preantral follicles; b) extended storage times caused progressive morphological abnormalities, disassembling of microtubules and DNA damage; c) storage up to 48 h did not influence in vitro meiotic maturation of oocytes nor cleavage after in vitro fertilization. However, only oocytes stored within the ovary for 24 h produced blastocysts in a percentage similar to control oocytes; d) GSH levels of in vitro matured oocytes did not change at any time during ovary storage; a progressive increase in ROS levels was detected from 48 h associated with elevated lipid peroxidation at 72 and 96 h of storage.

CONCLUSIONS

Storage of cat ovaries for up to 24 h caused minimal alteration of preantral follicles and oocytes. The extension of the storage period beyond 24 h progressively impaired the structure of follicles, and modified the oxidative status of in vitro matured oocytes and their developmental competence after in vitro fertilization. This information may help when setting up programs for fertility conservation, especially for wild feline species which die in geographic areas located far away from ARTs centers.

Transplantation of cryopreserved ovarian tissue in a patient affected by metastatic struma ovarii and endometriosis

In this case report, the outcomes of cryopreserved ovarian tissue transplantation performed in a patient affected by struma-ovarii associated with mature cystic teratoma, recurrent endometriotic cysts and diffuse peritoneal malignant struma-ovarii implants were described. Before cryopreservation, the patient underwent two left ovarian surgeries for enucleation cysts 8 years after righ salpingo-oophorectomy for struma-ovarii. Ovarian biopsy was collected in another hospital and transported to our laboratory for cryopreservation. The patient was submitted to radioiodine-therapy for metastases from malignant struma-ovarii. After treatment she experienced premature ovarian failure. Ten years after cryopreservation, a first orthotopic transplantation was performed in the left ovary and in a peritoneal pocket. Before transplantation, ovarian samples were analyzed to assess neoplastic contamination and tissue quality. Three years later, a second transplantation was heterotopically performed in abdominal subcutaneous sites. The analysis on thawed ovarian tissue did not reveal micrometastasis and they showed follicle and stroma damages. After transplantation few small follicles were observed at ultrasound examination and hormonal levels remained at menopausal values. To date no ovarian function recovery has been observed. The report highlights that ovarian tissue cryopreservation after multiple ovarian surgery may have some limitations. An accurate counseling should be offered to patients who wish to preserve fertility.

Nonhuman Primates: A Vital Model for Basic and Applied Research on Female Reproduction, Prenatal Development, and Women's Health

The comparative biology of reproduction and development in mammalian species is remarkable. Hence, because of similarities in environmental and neuroendocrine control of the reproductive axis, the cyclic function of the ovary and reproductive tract, establishment and control of the maternal-fetal-placental unit during pregnancy, and reproductive aging from puberty through menopause, nonhuman primates (NHPs) are valuable models for research related to women's reproductive health and its disorders. This chapter provides examples of research over the past 10+ years using Old World monkeys (notably macaque species), baboons, and to a lesser extent New World monkeys (especially marmosets) that contributed to our understanding of the etiology and therapies or prevention of: (1) ovarian disorders, e.g., polycystic ovary syndrome, mitochondrial DNA-based diseases from the oocyte; (2) uterine disorders, for example, endometriosis and uterine transplantation; and (3) pregnancy disorders, for example, preterm labor and delivery, environmental factors. Also, emerging opportunities such as viral (e.g., Zika) induced fetal defects and germline genomic editing to generate valuable primate models of human diseases (e.g., Huntington and muscular dystrophy) are addressed. Although the high costs, specialized resources, and ethical debate challenge the use of primates in biomedical research, their inclusion in fertility and infertility research is vital for continued improvements in women's reproductive health.

A transportation network for human ovarian tissue is indispensable to success for fertility preservation

PURPOSE

The purpose of this study was to examine the efficacy of an ovarian tissue transportation network for fertility preservation (FP) for cancer patients in Japan.

METHODS

PubMed was searched for papers on transportation of human ovarian tissue for FP. We analyzed population, area, number of cancer patients for ovarian tissue cryopreservation (OTC), quality control/assessment and safety, cost of a cryopreservation center for the building for 30 years, and medical fees of cancer patients (operation, cryopreservation, and storage of ovarian tissue).

RESULTS

More than twenty babies have been born in Denmark and Germany through a transportation system. Up to 400 new patients a year need OTC. The fees for removal, cryopreservation, and storage for 5 years, and transplantation of ovarian tissue are around €5,000, €4,000, and €5,000, respectively. It costs more than €5 million to establish and maintain one cryopreservation center for 30 years. If we have a few cryopreservation centers in Japan, we can cryopreserve 400 patients' ovarian tissue per year by safer slow freezing and maintain quality control/assessment. We need to lighten the patients' burden for easy to use FP by a government subsidy and medical insurance coverage.

CONCLUSIONS

This model has been termed the Danish model ("the woman stays - the tissue moves"). This is truly patient-centered medicine. We can have maximum effects with the minimum burden. A transportation network like those of Denmark and Germany is the best strategy for FP in Japan. It may be the best system for cancer patients, medical staff, and the Ministry of Health, Labor, and Welfare.