Ovarian Tissue Transplantation: Experience From Germany and Worldwide Efficacy

Fertility protection: a novel approach using pretreatment with mesenchymal stem cell exosomes to prevent chemotherapy-induced ovarian damage in a mouse model

BACKGROUND

Primary ovarian insufficiency refers to the loss of ovarian function before the age of 40 years and leads to amenorrhea and infertility. Primary ovarian insufficiency has diverse causes, but a common cause is exposure to gonadotoxic chemotherapy used in cancer treatment. Because of the risk for developing primary ovarian insufficiency, patients who want to preserve their fertility may consider various procedures for fertility preservation. However, current fertility preservation options are highly invasive, carry substantial risks, and have uncertain success rates. Recent studies from our group and others reported that mesenchymal stem cells and mesenchymal stem cell-derived exosomes can restore ovarian function in preclinical models of primary ovarian insufficiency by restoring damaged cells and inhibiting apoptosis. Although the restorative effect of mesenchymal stem cell-derived exosomes has been well reported in previous studies, the potential of mesenchymal stem cell-derived exosomes in preventing ovarian damage has not been fully elucidated.

OBJECTIVE

This study hypothesized that the antiapoptotic potential of mesenchymal stem cell-derived exosomes may protect ovarian tissue from chemotherapy-induced damage.

STUDY DESIGN

In this study, we delivered mesenchymal stem cell-derived exosomes directly into the ovaries of mice before administration of chemotherapy. A total of 60 mice were divided into 3 groups (20 per group), which were labeled the control, chemotherapy, and fertility protection groups. Only the fertility protection group mice received exosomes, whereas the control and chemotherapy group mice received saline. After exosome injection, the chemotherapy and fertility protection groups of mice were subjected to chemotherapy to induce ovarian damage. After chemotherapy, we evaluated the protective effects of exosome treatment on ovarian function, such as estrous cyclicity, serum hormone levels, and the fertility rate, by comparing these outcomes between the chemotherapy and fertility protection groups. These outcomes were also compared with those of the control group for comparison with outcomes under healthy conditions.

RESULTS

After intraovarian injection of exosomes before chemotherapy, the mice were able to maintain their estrous cycle (4- to 5-day cyclicity), serum anti-müllerian hormone level (66.06±26.40 ng/mL, not significantly different from that of the healthy controls), folliculogenesis (32.2±11.3 in the chemotherapy group vs 46.4±14.1 in the fertility protection group; P<.05), expression of the steroidogenic acute regulatory protein gene (a the steroidogenesis marker) (0.44±0.11-fold expression in the chemotherapy group and 0.88±0.31-fold expression in the fertility protection group; P<.05), and fertility (2 of 8 in the chemotherapy group and 5 of 8 in the fertility protection group), thereby showing prevention of chemotherapy-induced damage. We found that exosome treatment before chemotherapy can preserve ovarian function and protect fertility through the overexpression of ATP synthase-binding cassette transporters, such as ABCB1b (10.17±17.75-fold expression in the chemotherapy group and 44.14±33.25-fold expression in the fertility protection group; P<.05) and ABCC10 (3.25±0.59-fold expression in the chemotherapy group and 5.36±1.86-fold expression in the fertility protection group; P<.05).

CONCLUSION

In this study, we present a novel fertility protection method using mesenchymal stem cell-derived exosomes. We concluded that mesenchymal stem cell-derived exosomes are a promising and simple treatment option for fertility protection in reproductive-aged patients who are receiving gonadotoxic chemotherapy.

Curcumin and gallic acid have a synergistic protective effect against ovarian surface epithelium and follicle reserve damage caused by autologous intraperitoneal ovary transplantation in rats

The objective of this study to examine the effects of curcumin and gallic acid use against oxidative stress damage in the autologous intraperitoneal ovarian transplantation model created in rats on ovarian follicle reserve, ovarian surface epithelium, and oxidant-antioxidant systems. 42 adult female Sprague Dawley rats (n=7) were allocated into 6 groups. Group 1 served as the control. In Group 2, rats underwent ovarian transplantation (TR) to their peritoneal walls. Group 3 received corn oil (CO) (0.5 ml/day) one day before and 14 days after transplantation. Group 4 was administered curcumin (CUR) (100 mg/kg/day), Group 5 received gallic acid (GA) (20 mg/kg/day), and Group 6 was treated with a combination of curcumin and gallic acid via oral gavage after transplantation. Rats were sacrificed on the 14th postoperative day, and blood along with ovaries were collected for analysis. The removed ovaries were analyzed at light microscopic, fluorescence microscopic, and biochemical levels. In Group 2 and Group 3, while serum and tissue Total Oxidant Levels (TOS) and Oxidative Stress Index (OSI) increased, serum Total Antioxidant Levels (TAS) decreased statistically significantly (p˂0.05) compared to the other groups (Groups 1, 4, 5, and 6). The ovarian follicle reserve was preserved and the changes in the ovarian surface epithelium and histopathological findings were reduced in the antioxidant-treated groups (Groups 4, 5, and 6). In addition, immunofluorescence examination revealed that the expression of Cytochrome C and Caspase 3 was stronger and Ki-67 was weaker in Groups 2 and 3, in comparison to the groups that were given antioxidants. It can be said that curcumin and gallic acid have a histological and biochemical protective effect against ischemia-reperfusion injury due to ovarian transplantation, and this effect is stronger when these two antioxidants are applied together compared to individual use.

Oocyte collection and outcome following oncologic treatment: a retrospective multicentre study

PURPOSE

This study assesses fertility treatment outcomes in female patients who had undergone successful oocyte retrieval following cancer therapy.

METHODS

Between January 2020 and December 2022, we collected fertility treatment data from six participating centres in Spain and Germany. All patients associated with this data had undergone successful oocyte retrieval following cancer treatment.

RESULTS

Women had most frequently been diagnosed with a haematological (41.9%), breast (22.6%) or gynaecological malignancy (12.9%); two thirds (67.7%) had previously received a chemotherapy, half a radiotherapy (53.3%) and 45.2% had undergone surgery. On average, 7 years (range 0-28) had passed between cancer treatment and first ovarian stimulation cycle. Forty-nine ovarian stimulation cycles had been conducted on these 31 women between 2004 and 2021 (mean age at first oocyte collection following treatment: 34.8 ± 5.7 years). On average, 7 oocytes were collected per cycle (range 0-26) and 11 were collected per patient (range 0-51). Out of the 190 oocytes collected for immediate use of artificial reproductive technique, 139 were fertilised at a rate of 73%. Live birth rate per fresh transfer was 45% (9/20); no births were reported following cryotransfer (0/10). Mean values of anti-Mullerian hormone (AMH) before stimulation declined with time since treatment; however, oocytes were successfully collected from four women with an AMH of <0.5 ng/ml, although no pregnancies were reported. Ten pregnancies were documented; 3 ended in miscarriage. Two twin and 5 single pregnancies resulted in nine live births. On average, children were carried to term.

CONCLUSION

In this small cohort, oocytes were successfully collected after chemotherapy and radiotherapy, despite-in individual cases-low AMH values. Further studies are needed to enrich the database and ultimately provide appropriate counselling to female cancer patients regarding expectations and ART outcome following cancer therapy.

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.

The report of ovarian tissue transplant in Iran: A case report

Background

Cancer treatments such as chemotherapy and radiotherapy increase the chance of ovarian failure. Ovarian tissue transplantation (OTT) is a viable option for fertility preservation in these cases. We aim to report ovarian transplantation in a leukemia case undergoing the vitrification method.

Case Presentation

The case was a 28-yr-old female in Research and Clinical Center for Infertility, Yazd, Iran who was suffering from leukemia. Ovarian biopsy was performed by laparoscopy surgery and transported to cryopreservation lab at 4 C for 1-2 hr. The ovarian cortex was removed from the medulla, and ovarian strips were cryopreserved by vitrification. This procedure used the equilibration and vitrification solutions including medium 199 supplemented with 20% serum, and ethylene glycol and dimethyl sulfoxide with concentrations of 7.5% and 20%, respectively. Before doing OTT, we assessed the tissue viability and follicular count by chick embryo chorioallantoic membranes and histologic survey, respectively. OTT was done after complete remission, following warmed tissue sutured together and transplanted on the residual medulla on the right side. On the left side, the ovary was removed completely; however, 2 strips were put on the peritoneal pocket. Anti-Müllerian hormone, follicle-stimulating hormone, and luteinizing hormone levels were 0.1 ng/mL, 36.5 mIU/mL, and 19.8 mIU/mL before OTT. During a 6-month follow-up, the anti-Müllerian hormone increased to 0.9, and then follicle-stimulating hormone and luteinizing hormone levels decreased dramatically until 17.47 mIU/mL and 6.71 mIU/mL, respectively. Also, the patient had 3 cycles of menstrual periods.

Conclusion

We demonstrated an appropriate hormonal profile, and the restoration of the menstrual cycle might indicate a successful transplant. Further investigations are needed to achieve successful clinical outcomes.

Preservation of fertility in female patients with hematologic diseases

Recent developments of assisted reproduction techniques turned possible to avoid the infertility consequences of oncologic treatments, but fertility preservation (FP) has been somewhat neglected in women with hematologic diseases undergoing gonadotoxic treatments. For these specific cases, the current options for FP include the cryopreservation of embryos, mature oocytes and ovarian tissue, and oocyte in-vitro maturation. We intend to make patients and clinicians aware of this important and relevant issue, and provide hematologists, assisted reproduction physicians and patients, with updated tools to guide decisions for FP. The physicians of the units responsible for female FP should always be available to decide on the best-individualized FP option in strict collaboration with hematologists. With a wide range of options for FP tailored to each case, a greater level of training and information is needed among clinicians, so that patients proposed to gonadotoxic treatments can be previously advised for FP techniques in hematological conditions. ABBREVIATED ABSTRACT: Recent developments of assisted reproduction techniques turned possible to preserve the fertility of women with hematologic diseases undergoing gonadotoxic treatments. Current options for fertility preservation in women with hematologic diseases are presented. It is imperative to offer fertility preservation to all women before starting any gonadotoxic treatment and in some cases after treatment. Fertility preservation methods enable to later achieve the desired pregnancy.

Chemotherapy-induced ovarian damage and protective strategies

More than 9.2 million women worldwide suffer from cancer, and about 5% of them are at reproductive age. Chemotherapy-induced impairment of fertility affects the quality of life of these women. Several chemotherapeutic agents have been proven to cause apoptosis and autophagy by inducing DNA damage and cellular stress. Injuries to the ovarian stroma and micro-vessel network are also considered as pivotal factors resulting in ovarian dysfunction induced by chemotherapeutic agents. Primordial follicle pool over-activation may also be the mechanism inducing damage to the ovarian reserve. Although many studies have explored the mechanisms involved in chemotherapy-induced reproductive toxicity, the exact molecular mechanisms have not been elucidated. It is essential to understand the mechanisms involved in ovarian damage, in order to develop potential protective treatments to preserve fertility. In this article, we reviewed the current knowledge on the mechanism of chemotherapy-induced ovarian damage and possible protective strategies that prevent the ovary from such damages.

Ovarian tissue cryopreservation and transplantation: a review on reactive oxygen species generation and antioxidant therapy

Cancer is the leading cause of death worldwide. Fortunately, the survival rate of cancer continues to rise, owing to advances in cancer treatments. However, these treatments are gonadotoxic and cause infertility. Ovarian tissue cryopreservation and transplantation (OTCT) is the most flexible option to preserve fertility in women and children with cancer. However, OTCT is associated with significant follicle loss and an accompanying short lifespan of the grafts. There has been a decade of research in cryopreservation-induced oxidative stress in single cells with significant successes in mitigating this major source of loss of viability. However, despite its success elsewhere and beyond a few promising experiments, little attention has been paid to this key aspect of OTCT-induced damage. As more and more clinical practices adopt OTCT for fertility preservation, it is a critical time to review oxidative stress as a cause of damage and to outline potential ameliorative interventions. Here we give an overview of the application of OTCT for female fertility preservation and existing challenges; clarify the potential contribution of oxidative stress in ovarian follicle loss; and highlight potential ability of antioxidant treatments to mitigate the OTCT-induced injuries that might be of interest to cryobiologists and reproductive clinicians.

The mTOR Inhibitor Rapamycin Counteracts Follicle Activation Induced by Ovarian Cryopreservation in Murine Transplantation Models

Background and Objectives: Ovarian tissue cryopreservation followed by autotransplantation (OTCTP) is currently the only fertility preservation option for prepubertal patients. Once in remission, the autotransplantation of frozen/thawed tissue is performed when patients want to conceive. A major issue of the procedure is follicular loss directly after grafting mainly due to follicle activation. To improve follicular survival during the OTCTP procedure, we inhibited the mTOR pathway involved in follicle activation using rapamycin, an mTOR inhibitor. Next, we compared two different in vivo models of transplantation: the recently described non-invasive heterotopic transplantation model between the skin layers of the ears, and the more conventional and invasive transplantation under the kidney capsule. Materials and Methods: To study the effects of adding rapamycin during cryopreservation, 4-week-old C57BL/6 mouse ovaries, either fresh, slow-frozen, or slow-frozen with rapamycin, were autotransplanted under the kidney capsule of mice and recovered three weeks later for immunohistochemical (IHC) analysis. To compare the ear with the kidney capsule transplantation model, fresh 4-week-old C57BL/6 mouse ovaries were autotransplanted to either site, followed by an injection of either LY294002, a PI3K inhibitor, vehicle control, or neither, and these were recovered three weeks later for IHC analysis. Results: Rapamycin counteracts cryopreservation-induced follicle proliferation, as well as AKT and mTOR pathway activation, in ovaries autotransplanted for three weeks under the kidney capsule of mice. Analyses of follicle proliferation, mTOR activation, and the effects of LY294002 treatment were similar in transplanted ovaries using either the ear or kidney capsule transplantation model. Conclusions: By adding rapamycin during the OTCTP procedure, we were able to transiently maintain primordial follicles in a quiescent state. This is a promising method for improving the longevity of the ovarian graft. Furthermore, both the ear and kidney capsule transplantation models were suitable for investigating follicle activation and proliferation and pharmacological strategies.

[Fertility and fertility preservation in women]

BACKGROUND

Advances in the treatment of cancer and in reproductive medicine make it possible for many patients to start their family planning even after cytotoxic therapy. Depending on the age of the patient, the planned oncological therapy and its urgency, various methods can be used to preserve the fertility of affected women.

OBJECTIVES

Presentation of facts about fertility, as well as information about fertility-preserving methods for women, so that they can be discussed with and offered to patients.

MATERIALS AND METHODS

Presentation and discussion of basic research, clinical data, and expert recommendations on fertility and fertility preservation.

RESULTS

Well-established fertility-protective techniques now exist for women that offer a realistic chance of subsequent pregnancy. These include transposition of the gonads prior to radiotherapy, gonadal protection with gonadotropin-releasing hormone (GnRH) analogues and cryopreservation of fertilized and unfertilized oocytes, as well as cryopreservation of ovarian tissue.

CONCLUSIONS

Fertility-protective techniques are an integral part of oncological treatments for prepubertal girls and patients of reproductive age. The various measures must be discussed individually with the patient as part of a multimodal concept. Prompt and timely collaboration with a specialized center is essential.

Long-term follow-up to assess criteria for ovarian tissue cryopreservation for fertility preservation in young women and girls with cancer

STUDY QUESTION

Do the Edinburgh Selection Criteria correctly identify female cancer patients under the age of 18 who are at risk of premature ovarian insufficiency (POI) as candidates for ovarian tissue cryopreservation (OTC)?

SUMMARY ANSWER

Patient assessment using these criteria accurately identifies those at risk of POI, who can be offered OTC and future transplantation as a means of fertility preservation.

WHAT IS KNOWN ALREADY

Treatment for childhood cancer can have adverse consequences on future fertility; at the time of diagnosis, fertility risk assessment should be undertaken in order to identify patients to whom fertility preservation should be offered. The Edinburgh selection criteria, based on planned cancer treatment and patient health status, are utilized to identify those at high risk and therefore eligible for OTC. However, this procedure is not without risk and there are few data on the efficacy of the procedure in prepubertal patients. As such, long-term follow-up of reproductive outcomes is necessary, to ensure that OTC is being offered appropriately.

STUDY DESIGN, SIZE, DURATION

Cohort study encompassing all females diagnosed with cancer under the age of 18 in South East Scotland, from 1 January 1996 to 30 April 2020. Patients were followed up for reproductive outcomes to assess for diagnosis of POI.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 638 eligible patients were identified; patients under the age of 12 or deceased before the age of 12 were excluded from the study, leaving a study population of 431 patients. Electronic records were reviewed for reproductive function, assessed by current menstruation, pregnancy (in the absence of POI diagnosis), reproductive hormone measurements, pubertal progression, or diagnosis of POI. Patients on hormonal contraception (other than for treatment of POI or panhypopituitarism with no history of gonadatoxic treatment) were excluded from analysis (n = 9). Analysis on remaining 422 patients was carried out using the Kaplan-Meier methods, with POI as the defined event, and Cox proportional hazards model.

MAIN RESULTS AND THE ROLE OF CHANCE

In the study population of 431 patients, median ages at diagnosis and analysis were 9.8 and 22.2 years, respectively. Reproductive outcomes were unavailable in 142 patients; the assumption was made that these patients did not have POI, but a subanalysis excluding these patients was also performed. Of the 422 patients aged >12 at analysis and not taking hormonal contraception, OTC was offered to 37 patients and successfully performed in 25 patients. Of the 37 patients offered OTC (one at time of relapse), nine (24.3%) developed POI. Of the 386 not offered OTC, 11 (2.9%) developed POI. The probability of developing POI was significantly higher in those offered OTC (hazard ratio [HR] 8.7 [95% CI 3.6-21]; P < 0.0001), even when those patients with unknown outcomes were excluded from the analysis (HR 8.1 [95% CI 3.4-20]; P < 0.001). All patients offered OTC who developed POI did so after treatment for primary disease; in those not offered OTC, five patients (45.5%) developed POI after treatment for disease relapse.

LIMITATIONS, REASONS FOR CAUTION

A significant number of patients had unknown reproductive outcomes; many of these patients were engaged in ongoing follow-up but did not have documented reproductive assessment. This may have introduced bias to the analysis and highlights the need for reproductive follow-up as part of routine cancer aftercare. In addition, the relatively young age of the patient population and short duration of follow-up in some cases demonstrates the need for ongoing follow-up of this cohort.

WIDER IMPLICATIONS OF THE FINDINGS

The prevalence of POI after childhood cancer is low, but the Edinburgh selection criteria remain a robust tool for selecting those at high risk at the time of diagnosis, to offer OTC appropriately. However, disease relapse necessitating more intensive treatments remains a challenge. This study additionally highlights the importance of routine assessment and documentation of reproductive status in haematology/oncology follow-up.

STUDY FUNDING/COMPETING INTEREST(S)

K.D. is supported by a CRUK grant (C157/A25193). This work was undertaken in part in the MRC Centre for Reproductive Health, (supported by MRC grant MR/N022556/1). R.A.A. has received consulting fees from Ferring and Roche Diagnostics; payment from Merck and IBSA for educational events; and laboratory materials from Roche Diagnostics. The other authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Setup of a cryobank for ovarian tissue in a university-based setting

Establishing and maintaining a newly set-up cryobank for ovarian tissue in a university setting requires at least 1 year's notice to start financial, spatial, lab equipment, and employee acquisition planning. Right before and after the start of the cryobank, the newly founded team should introduce itself to the hospitals and local and national health systems via mail, print flyers, and symposia in order to share the possibilities and the knowledge. Potential referrers should be provided with standard operating procedures and advice on getting used to the new system. Especially in the first year after the establishment, all procedures should be internally audited in order to avoid possible difficulties.

Advances of xenogeneic ovarian extracellular matrix hydrogels for in vitro follicle development and oocyte maturation

Research aimed at preserving female fertility is increasingly using bioengineering techniques to develop new platforms capable of supporting ovarian cell function in vitro and in vivo. Natural hydrogels (alginate, collagen, and fibrin) have been the most exploited approaches; however they are biologically inert and/or biochemically simple. Thus, establishing a suitable biomimetic hydrogel from decellularized ovarian cortex (OC) extracellular matrix (OvaECM) could provide a complex native biomaterial for follicle development and oocyte maturation. The objectives of this work were (i) to establish an optimal protocol to decellularize and solubilize bovine OC, (ii) to characterize the histological, molecular, ultrastructural, and proteomic properties of the resulting tissue and hydrogel, and (iii) to assess its biocompatibility and adequacy for murine in vitro follicle growth (IVFG). Sodium dodecyl sulfate was identified as the best detergent to develop bovine OvaECM hydrogels. Hydrogels added into standard media or used as plate coatings were employed for IVFG and oocyte maturation. Follicle growth, survival, hormone production, and oocyte maturation and developmental competence were evaluated. OvaECM hydrogel-supplemented media best supported follicle survival, expansion, and hormone production, while the coatings provided more mature and competent oocytes. Overall, the findings support the xenogeneic use of OvaECM hydrogels for future human female reproductive bioengineering.

Encapsulated Allografts Preclude Host Sensitization and Promote Ovarian Endocrine Function in Ovariectomized Young Rhesus Monkeys and Sensitized Mice

Transplantation of allogeneic donor ovarian tissue holds great potential for female cancer survivors who often experience premature ovarian insufficiency. To avoid complications associated with immune suppression and to protect transplanted ovarian allografts from immune-mediated injury, we have developed an immunoisolating hydrogel-based capsule that supports the function of ovarian allografts without triggering an immune response. Encapsulated ovarian allografts implanted in naïve ovariectomized BALB/c mice responded to the circulating gonadotropins and maintained function for 4 months, as evident by regular estrous cycles and the presence of antral follicles in the retrieved grafts. In contrast to non-encapsulated controls, repeated implantations of encapsulated mouse ovarian allografts did not sensitize naïve BALB/c mice, which was confirmed with undetectable levels of alloantibodies. Further, encapsulated allografts implanted in hosts previously sensitized by the implantation of non-encapsulated allografts restored estrous cycles similarly to our results in naïve recipients. Next, we tested the translational potential and efficiency of the immune-isolating capsule in a rhesus monkey model by implanting encapsulated ovarian auto- and allografts in young ovariectomized animals. The encapsulated ovarian grafts survived and restored basal levels of urinary estrone conjugate and pregnanediol 3-glucuronide during the 4- and 5-month observation periods. We demonstrate, for the first time, that encapsulated ovarian allografts functioned for months in young rhesus monkeys and sensitized mice, while the immunoisolating capsule prevented sensitization and protected the allograft from rejection.

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.

Drastic Loss of Antral Follicles Due to Gene Expression Dysregulation Occurs on the First Day After Subcutaneous Ovarian Transplantation

Ovarian cryopreservation is an alternative for the preservation of fertility, and the subcutaneous transplantation site is considered one of the most promising. Studies evaluating the follicular growth and its relationship with gene expression and vascular perfusion are essential for improving this technique and its clinical application. Thus, the aim of this study was to evaluate the effect of subcutaneous autotransplantation and vitrification on follicular growth and atresia and their relationship with vascular perfusion and gene expression. Therefore, female mice were ovariectomized, and the ovaries were divided in two experimental groups (1) vitrified (treatment, n = 97) and (2) not vitrified (control, n = 97) and subsequently were transplanted. Then grafts, from both groups, were recovered after 1, 12, or 23 days (D1, D12, D23) and subjected to follicular quantification, morphometry, and qPCR. Non-transplanted ovaries (D0) were also used. The estrous cycle and vascular perfusion were monitored throughout the experiment. On D9, 100% of the animals had reestablished their estrous cycles (p > 0.05). Blood perfusion at the transplant site was similar for both treatments (p > 0.05), with greater perfusion at the site of vitrified transplants only on D1 (p < 0.05). A drastic reduction in the number of antral follicles and an increased number of atretic follicles were observed on D1 (p < 0.0001), associated with upregulation of Casp3, Fshr, and Igf1r; and downregulation of Bax, Acvr1, Egfr, and Lhcgr (p < 0.05). Our findings indicate that the first day after subcutaneous transplantation is a critical period for follicular survival, with intense follicular atresia independent of Bax upregulation.

A New Bioreactor to Promote Human Follicular Growth with or without Activin A in Transgender Men

The aim of the present study was to evaluate the effect of activin A on the activation of in vitro folliculogenesis of human ovarian tissues from transgender men with or without our new compartmented chitosan hydrogel microbioreactor (“three-dimensional (3D)-structure”) enabling a three-dimensional tissue culture. Five fresh ovarian human tissues were cultured in vitro for 20 or 22 days in four groups with 100 ng/mL activin A or without activin A during the last six to eight days of culture, and within a 3D-structure or without the 3D-structure in standard conditions. Follicular density and quality were evaluated, and follicular diameters were measured. Estradiol secretion was quantified. Proliferation and apoptosis through immunostaining were also performed. The proportion of primordial follicles was significantly reduced, and the proportion of primary and secondary follicles was significantly increased in all four groups (p < 0.001). Tertiary follicles were observed in the four culture groups. Activin A supplementation did not significantly affect the follicular density, follicular quality, follicular growth, or estradiol secretion (p > 0.05). The 3D-structure increased the density of primary follicles and decreased the estradiol secretion (p < 0.001). Follicular proliferation was significantly lower in the 3D-structure group compared to the non-3D-structure group (p = 0.008). Regarding follicular apoptosis, it was significantly higher in the activin group compared to the non-activin group (p = 0.006). Activin A did not seem to play a key role in the in vitro folliculogenesis activation in our culture conditions. However, the results may indicate that the 3D-structure could be more physiological and could prevent a detrimental in vitro folliculogenesis flare-up.

Ovarian tissue cryopreservation in Malaysia: a case series

OBJECTIVES

We aim to discuss the hematological cancer cases that opted for ovarian tissue cryopreservation (OTC) as fertility preservation before the gonadotoxic chemotherapy agent.

CASE PRESENTATION

The ovarian tissue cryopreservation (OTC) was started in August 2020 in our center. Up to now, there were four cases have been performed and included in this report. The ovarian tissue cortex was cryopreserved with cryoprotectant using Kitazato™ (Tokyo, Japan) media and fit in the closed system devices. A total of four post-OTC patients were included. The mean age was 24 years old, whereas the mean serum AMH level was 30.43 pmol/L. Most of them were diagnosed with lymphoma, except one was leukemia. All of them received additional GnRH analog following OTC as a chemoprotective agent before cancer treatment. Currently, they are recovering well and on regular follow-up with the hematological department.

CONCLUSIONS

Although The OTC is an ultimate option for prepubertal girls, it can be proposed as a good strategy for adult cancer women who could not delay cancer therapy.

Determinants of transplantation success with cryopreserved ovarian tissue: data from 196 women of the FertiPROTEKT network

STUDY QUESTION

What are the pregnancy and live birth rates for ovarian tissue transplantation and which factors are associated with the success rate?

SUMMARY ANSWER

Pregnancy and live birth rates per transplanted woman are 32.7% and 26.5% and success rate is associated with female age and first versus repeated transplantation.

WHAT IS KNOWN ALREADY

Live birth rates after ovarian tissue transplantations have been reported to be between around 24% and 41% per patient. Success rates seem to be negatively associated with increasing female age at the time of tissue cryopreservation and with pelvic radiation. Success rates are apparently not reduced after overnight transportation of ovarian tissue before freezing.

STUDY DESIGN, SIZE, DURATION

Registry analysis of 244 transplantations in 196 women, performed by 26 FertiPROTEKT network centres from 2007 to 2019 with follow-up till December 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Orthotopic ovarian tissue transplantations were performed in 196 women, 191 with previous malignant and 5 with previous non-malignant diseases. Size of transplanting centres varied between 1 and 100 transplantations per centre (median: 2). Factors possibly associated with success rate such as female age, first and repeated transplantation, experience of the transplanting centre and overnight transportation of the ovarian tissue before freezing were analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

Average age of all 196 transplanted women was 31.3 years (SD 5.2; range 17-44) at the time of cryopreservation of tissue and 35.9 years (SD 4.8; range 23-47) at the time of transplantation. Pregnancy rate was 30.6% (95% CI, 24.2-37.6%) per first transplantation and 32.7% (95% CI, 26.1-39.7%) per patient. Pregnancy rate was higher after first transplantation (30.6% (95% CI, 24.2-37.6%)) compared to second and subsequent transplantations (11.8% (95% CI, 3.3-27.5%)). Live birth rate per first transplantation was 25.0% (95% CI, 19.1-31.7%) and per patient 26.5% (95% CI, 20.5-33.3%). Success rate decreased with increasing age at the time of ovarian tissue freezing. Live birth rate was 28.2% (95% CI, 20.9-36.3%) in women <35 years and 16.7% (95% CI, 7.9-29.3%) in women >35 years. Pregnancy rates after first transplantation were higher in centres who had performed ≥10 transplantations (35.1%) compared to centres with <10 transplantation (25.4%) (P = 0.12). Corresponding live birth rates were 27.0% and 18.6%. Success rates were not different in women with and without overnight transportation of tissue before cryopreservation.

LIMITATIONS, REASONS FOR CAUTION

The data were drawn from a registry analysis. Data such as ovarian reserve and premature ovarian insufficiency were not available for all women. Data might be influenced by different follow-up policies of the centres.

WIDER IMPLICATIONS OF THE FINDINGS

The study reveals the high potential of ovarian tissue freezing and transplantation, but only if freezing is performed in younger women. The study suggests focus should be placed on the first and not on repeated transplantations. It also opens the discussion of whether transplantation should rather be performed by experienced centres.

STUDY FUNDING/COMPETING INTEREST(S)

No funding. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

What should be done in terms of fertility preservation for patients with cancer? The French 2021 guidelines

AIM

To provide practice guidelines about fertility preservation (FP) in oncology.

METHODS

We selected 400 articles after a PubMed review of the literature (1987-2019).

RECOMMENDATIONS

Any child, adolescent and adult of reproductive age should be informed about the risk of treatment gonadotoxicity. In women, systematically proposed FP counselling between 15 and 38 years of age in case of treatment including bifunctional alkylating agents, above 6 g/m2 cyclophosphamide equivalent dose (CED), and for radiation doses on the ovaries ≥3 Gy. For postmenarchal patients, oocyte cryopreservation after ovarian stimulation is the first-line FP technique. Ovarian tissue cryopreservation should be discussed as a first-line approach in case of treatment with a high gonadotoxic risk, when chemotherapy has already started and in urgent cases. Ovarian transposition is to be discussed prior to pelvic radiotherapy involving a high risk of premature ovarian failure. For prepubertal girls, ovarian tissue cryopreservation should be proposed in the case of treatment with a high gonadotoxic risk. In pubertal males, sperm cryopreservation must be systematically offered to any male who is to undergo cancer treatment, regardless of toxicity. Testicular tissue cryopreservation must be proposed in males unable to cryopreserve sperm who are to undergo a treatment with intermediate or severe risk of gonadotoxicity. In prepubertal boys, testicular tissue preservation is: - recommended for chemotherapy with a CED ≥7500 mg/m2 or radiotherapy ≥3 Gy on both testicles. - proposed for chemotherapy with a CED ≥5.000 mg/m2 or radiotherapy ≥2 Gy. If several possible strategies, the ultimate choice is made by the patient.

Investigation of the optimal culture time for warmed bovine ovarian tissues before transplantation

Ovarian tissue cryopreservation by vitrification is an effective technique, but there are still many unresolved issues related to the procedure. The aim of this study was to investigate the optimal culture time of post-warmed ovarian tissues and their viability before ovarian tissue transplantation. The bovine ovarian tissues were used to evaluate the effect of post-warming culture periods (0, 0.25, 0.5, 1, 2, 5 and 24 hours) in the levels of residual cryoprotectant, LDH release, ROS generation, gene and protein abundance, and follicle viability and its mitochondrial membrane potential. Residual cryoprotectant (CPA) concentration decreased significantly after 1 hour of culture. The warmed ovarian tissues that underwent between 0 to 2 hours of culture time showed similar LDH and ROS levels compared to fresh non-frozen tissues. The AMH transcript abundance did not differ in any of the groups. No increase in the relative transcript abundance and protein level of Caspase 3 and Cleaved-Caspase 3, respectively, in the first 2 hours of culture after warming. On the other hand, an increased protein level of double stranded DNA breaks (gamma-H2AX) was observed in post-warmed tissues disregarding the length of culture time, and a temporary reduction in pan-AKT was detected in post-warming tissues between 0 to 0.25 hours of culture time. Prolonged culture time lowered the percentage of viable follicles in warmed tissues, but it did not seem to affect the follicular mitochondrial membrane potential. In conclusion, 1 to 2 hours of culture time would be optimal for vitrified-warmed tissues before transplantation.

Endometriosis in women undergoing ovarian tissue transplantation due to premature menopause after gonadotoxic treatment or spontaneous premature ovarian failure

INTRODUCTION

Cryopreservation of ovarian tissue with subsequent transplantation is an efficient option for restoring fertility in women at risk of premature ovarian failure. The association between infertility and endometriosis is well recognized. Although endometriosis usually ends with the onset of natural or iatrogen menopause due to declining estrogen levels, endometriosis can in rare cases occur after menopause. This study aims to investigate women with premature menopause who were diagnosed with endometriosis during laparoscopy for ovarian tissue transplantation, and to address the questions of how endometriotic lesions after cytotoxic treatment and premature menopause might be explained, whether endometriosis affects pregnancy rates, and whether there is an association between endometriosis and the original cancer.

MATERIAL AND METHODS

Seventeen patients who had undergone ovarian tissue transplantation to restore their fertility and who were diagnosed with endometriosis during transplantation were included in this retrospective study. The endometriosis foci were completely removed and ovarian tissue was transplanted into the pelvic peritoneum. Preexisting conditions, use of hormonal preparations, endometriosis stage pain assessment, as well as pregnancy and live birth rate were evaluated.

RESULTS

The mean age of the patients was 29.5 ± 6.3 years (range 14-39) at the time of ovarian tissue harvest and 34.6 ± 4.3 years (range 28-40) at transplantation. Prior to transplantation, four patients had taken hormone replacement therapy, four women oral contraceptives and two patients' tamoxifen. Twelve women had stage I endometriosis and five stage II endometrioses according to the rASRM classification. Four patients reported dysmenorrhea. None of the women complained of general pelvic pain or dyspareunia. The pregnancy rate in the study population was 41.2%, with a live birth rate of 35.3%. The pregnancies occurred in three cases after spontaneous conception, in four women after a natural cycle IVF/ICSI.

CONCLUSIONS

This study highlights the under-researched association between endometriosis in women entering premature or early menopause either after gonadotoxic treatment or due to primary ovarian insufficiency. As more and more patients seek to have their cryopreserved ovarian tissue transplanted to fulfill their desire to have children, specialists will inevitably encounter women with this condition.

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.

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.

Why are women considering ovarian tissue cryopreservation to preserve reproductive and hormonal ovarian function? A qualitative study protocol

INTRODUCTION

Current fertility preservation options available to women are oocyte cryopreservation (egg freezing) or embryo cryopreservation. A newer procedure, ovarian tissue cryopreservation (OTC), has become available in some centres, which offers another option for women and girls considering fertility preservation. These procedures are commonly offered to women about to undergo treatments for cancer. OTC involves removing sections of ovarian tissue and cryopreserving it for future reimplantation, often several years later. OTC offers girls and women who may become infertile with optionality and the possibility of pregnancy. OTC has potential for other applications, including restoring ovarian endocrine function beyond biological menopause. This is not without controversy but has led to some women considering undergoing the procedure for purposes of ovarian hormonal preservation (conservation of ovarian endocrine function). OTC is invasive, involves two surgical procedures with concomitant risks and can be costly. Understanding why women may consider and ultimately undergo OTC is timely, so that evidence-based and women-centred care can be provided.

METHODS

A pragmatic narrative qualitative design will be used. A purposive sample of women aged 18-45 who are considering, or have sought, OTC will be recruited over 1-year period. Potential participants will be approached via a clinic that offers OTC on a private basis or via social media.

ANALYSIS

Participant interviews will be audio and, if consented, video recorded. These will be conducted face-to-face or virtually. The recordings will be transcribed verbatim and analysed using a thematic analysis approach supported by NVivo software.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Institutional Ethical Review ERN_19-1578A. We expect to disseminate the findings of this study through journal articles, conference presentations and multimedia to public.

A practical survey of fertility-preservation treatments in the startup phase in Japan

AIM

The actual status of fertility preservation treatments in the startup phase in Japan was investigated as a basis for discussing future directions.

METHODS

This study was conducted as "Research project to promote support of children and parenting 2016" which was supported by Ministry of Health in Japan with the approval of the institutional review board at St. Marianna University. Subjects of the survey were facilities registered with the Japan Society of Obstetrics and Gynecology as fertility preservation facilities, and facilities belonging to the Japan Association of Private Assisted Reproductive Technology Clinics and Laboratories. We provided questionnaires to survey both the medical care system and cases for which fertility preservation was implemented between 2006 and 2016.

RESULTS

Responses were obtained from 68 facilities (of the 64, 59 [92.2%] responded to the questionnaire and 9 clinics cooperated). Many facilities limited the cryopreservation of oocytes and ovaries to patients 40-41 years old and the use of eggs to patients 44-45 years old. In the patient survey, 812 cases of oocyte cryopreservation and 201 cases of ovarian tissue cryopreservation were performed during study period. Breast cancer was the most indicated disease, with oocyte cryopreservation in the late 30s and ovarian tissue cryopreservation in the early 30s. Very few babies were born from fertility preservation, and no live birth cases of ovarian tissue cryopreservation were identified.

CONCLUSIONS

Even from the early days, fertility preservation was implemented according to certain standards in Japan, but was characterized by a large variety of facilities.

In-vitro maturation and transplantation of cryopreserved ovary tissue: understanding ovarian longevity

RESEARCH QUESTION

Is it possible to use experience gained from 24 years of frozen ovarian transplantation, and from recent experience with in-vitro gametogenesis to accomplish simple and robust in-vitro maturation (IVM) of oocytes from human ovarian tissue?

DESIGN

A total of 119 female patients between age 2 and 35 years old underwent ovary cryopreservation (as well as in-vitro maturation of oocytes and IVM in the last 13 individuals) over a 24-year period. Up to 22 years later, 17 returned to have their ovary tissue thawed and transplanted back.

RESULTS

Every woman had a return of ovarian function 5 months after transplant, similar to previous observations. As observed before, anti-Müllerian hormone (AMH) concentration rose as FSH fell 4 months later. The grafts continued to work up to 8 years. Of the 17, 13 (76%) became pregnant with intercourse at least once, resulting in 19 healthy live births, including six live births from three women who had had leukaemia. Of the harvested germinal vesicle oocytes, 35% developed with simple culture media into mature metaphase II oocytes.

CONCLUSIONS

The authors concluded the following. First, ovary tissue cryopreservation is a robust method for preserving fertility even for women with leukaemia, without a need to delay cancer treatment. Second, many mature oocytes can often be obtained from ovary tissue with simple media and no need for ovarian stimulation. Third, ovarian stimulation only be necessary for removing the oocyte from the ovary, which can also be accomplished by simple dissection at the time of ovary freezing. Finally, pressure and just eight 'core genes' control primordial follicle recruitment and development.

A case of two ovarian tissue transplantations that led to a biochemical pregnancy in Japan

Ovarian tissue cryopreservation (OTC) and ovarian tissue transplantation (OTT) are fertility preservation options for prepubertal girls or those in whom cancer treatment cannot be delayed. They are important to increasing number of cancer survivors, but there are very few reports on this topic in Japan. This is the first report of a biochemical pregnancy after OTT in Japan. An 18-year-old woman, diagnosed with Ewing sarcoma of the seventh thoracic vertebra, underwent tumor resection. OTC was performed before postoperative chemotherapy. After 7 years, she decided to undergo OTT following the diagnosis of chemotherapy-induced premature ovarian insufficiency. On postoperative day 104, ovarian stimulation was started, yielding one embryo after 3 days. Embryo transfer was performed during a hormone replacement cycle. At 6 weeks and 1 day, the human chorionic gonadotropin level was 81.5 mIU/mL; however, no gestational sac was observed on ultrasonography, indicating a biochemical pregnancy. Our data will be useful for the further development of fertility preservation options in Japan in the future.

Installing oncofertility programs for breast cancer in limited versus optimum resource settings: Empirical data from 39 surveyed centers in Repro-Can-OPEN Study Part I & II

PURPOSE

As a further step to elucidate the actual diverse spectrum of oncofertility practices for breast cancer around the globe, we present and discuss the comparisons of oncofertility practices for breast cancer in limited versus optimum resource settings based on data collected in the Repro-Can-OPEN Study Part I & II.

METHODS

We surveyed 39 oncofertility centers including 14 in limited resource settings from Africa, Asia & Latin America (Repro-Can-OPEN Study Part I), and 25 in optimum resource settings from the United States, Europe, Australia and Japan (Repro-Can-OPEN Study Part II). Survey questions covered the availability of fertility preservation and restoration options offered to young female patients with breast cancer as well as the degree of utilization.

RESULTS

In the Repro-Can-OPEN Study Part I & II, responses for breast cancer and calculated oncofertility scores showed the following characteristics: (1) higher oncofertility scores in optimum resource settings than in limited resource settings especially for established options, (2) frequent utilization of egg freezing, embryo freezing, ovarian tissue freezing, GnRH analogs, and fractionation of chemo- and radiotherapy, (3) promising utilization of oocyte in vitro maturation (IVM), (4) rare utilization of neoadjuvant cytoprotective pharmacotherapy, artificial ovary, and stem cells reproductive technology as they are still in preclinical or early clinical research settings, (5) recognition that technical and ethical concerns should be considered when offering advanced and innovative oncofertility options.

CONCLUSIONS

We presented a plausible oncofertility best practice model to guide oncofertility teams in optimizing care for breast cancer patients in various resource settings.

Minimal residual disease detection by multicolor flow cytometry in cryopreserved ovarian tissue from leukemia patients

Background

Cryopreservation of ovarian tissue is a fertility-preservation option for women before gonadotoxic treatments. However, cryopreserved ovarian tissue transplantation must be performed with caution in women with malignancies that may metastasize to the ovaries. For this purpose, detecting minimal residual disease (MRD) in the ovarian cortex using sensitive methods is a crucial step. We developed an automated ovarian tissue dissociation method to obtain ovarian cell suspensions.

Results

We assessed MRD by multicolor flow cytometry (MFC) in cryopreserved ovarian cortex of 15 leukemia patients: 6 with B-cell acute lymphoblastic leukemia (B-ALL), 2 with T-cell acute lymphoblastic leukemia (T-ALL) and 7 with acute myeloid leukemia (AML). Ovarian MRD was positive in 5 of the 15 leukemia patients (one T-ALL and 4 AML). No B-ALL patient was positive by MFC. Quantitative reverse-transcribed polymerase chain reaction was performed when a molecular marker was available, and confirmed the MFC results for 3 patients tested. Xenografts into immunodeficient mice were also performed with ovarian cortical tissue from 10 leukemia patients, with no evidence of leukemic cells after the 6-month grafting period.

Conclusions

In conclusion, this is the first study using MFC to detect MRD in ovarian cortical tissue from acute leukemia patients. MFC has been accepted in clinical practice for its ease of use, the large number of parameters available simultaneously, and high throughput analysis. We demonstrate here that MFC is a reliable method to detect MRD in cryopreserved ovarian tissue, with a view to controlling the oncological risk before ovarian tissue transplantation in leukemia patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00936-4.

Fertility preservation in the pediatric population-experience from a German Cryobank for ovarian tissue

Counseling children on the possibility of fertility preservation prior to a gonadotoxic treatment supports the decision-making process, taking into account that the patients are in a very vulnerable and mentally exhausting situation following the diagnosis. Referral to specialists can be optimized on-site by routing slips with contact addresses, phone numbers, and mail contacts; available time slots for consultation; possibly offers for cost coverage; and an easy-to-understand information leaflet about the different options available. Some of the options for fertility preservation in the prepubertal population especially are still experimental. The unique possibility of fertility preservation before the onset of the gonadotoxic therapy, which may cause premature ovarian insufficiency or azoospermia in the future, should be highlighted.

Ovarian transplantation with robotic surgery and a neovascularizing human extracellular matrix scaffold: a case series in comparison to meta-analytic data

OBJECTIVE

To report our experience with robot-assisted (RA) autologous cryopreserved ovarian tissue transplantation (ACOTT) with the use of a neovascularizing extracellular matrix scaffold.

DESIGN

Case series with meta-analytic update.

SETTING

Academic.

PATIENT(S)

Seven recipients of RA-ACOTT.

INTERVENTION(S)

Before or shortly after initiating chemotherapy, ovarian tissue was cryopreserved from 7 women, who then underwent RA-ACOTT 9.9 ± 1.8 years (range, 7-12 years) later. Perioperatively, they received transdermal estrogen and low-dose aspirin to enhance graft vascularization. Ovarian cortical pieces were thawed and sutured on an extracellular matrix scaffold, which was then robotically anastomosed to the bivalved remaining ovary in 6 cases and retroperitoneally (heterotopic) to the lower abdomen in 1 case.

MAIN OUTCOME MEASURE(S)

Ovarian function return, the number of oocytes/embryos, aneuploidy %, live births, and neonatal outcomes were recorded. Graft longevity was compared with the mean from the meta-analytic data.

RESULT(S)

Ovarian function returned 13.9 ± 2.7 weeks (11-16.2 weeks) after ACOTT, and oocytes were retrieved in all cases with 12.3 ± 6.9 embryos generated. In contrast to orthotopic, the heterotopic ACOTT demonstrated low embryo quality and an 80% aneuploidy rate. A recipient did not attempt to conceive and 2 needed a surrogate, whereas 4 of 4 delivered 6 healthy children, compared with 115 of 460 (25% pregnancy rate) from the meta-analytic data (n = 79). The mean graft longevity (43.2 ± 23.6/47.4 ± 22.8 months with/without sensitivity analysis) trended longer than the meta-analytic mean (29.4 ± 22.7), even after matching age at cryopreservation.

CONCLUSION(S)

In this series, RA-ACOTT resulted in extended graft longevity, with ovarian functions restored in all cases, even when the tissues were cryopreserved after chemotherapy exposure.

Ovarian tissue bank for fertility preservation and anti-menopause hormone replacement

Traditional fertility preservation methods such as embryo or oocyte cryopreservation cannot meet the needs of a cancer patient or for personal reasons. The cryopreservation of ovarian tissue can be an alternative and has become a hot spot to preserve fertility or hormone replacement. The freezing of ovarian tissue can be carried out at any time without ovarian hyperstimulation to retrieve follicles. It is an ideal strategy to preserve reproductive function in children, adolescent cancer patients, and patients who are in urgent need of cancer treatment. With the increasing demands of women with premature ovarian failure or in menopause, ovarian tissue transplantation is also an alternative for hormone replacement that can provide physiological doses of hormone levels, which can avoid a series of risks such as thrombosis, breast cancer, or other hormone-dependent tumors, caused by oral hormone replacement. Hence, ovarian tissue banking can be regarded as a mainstream strategy for fertility preservation and anti-menopause hormone replacement in further clinical investigation.

Ovarian tissue cryopreservation in young females with cancer and its impact on ovarian follicle density

BACKGROUND

Cancer therapy in young females results in irreversible damage to their ovaries potentially leading to premature ovarian failure (POF) and infertility. Ovarian follicle density (FD) serves as a key predictor of reproductive potential for a woman. FD is significantly reduced after cryopreservation in adult women with cancer. FD in young females with cancer has not been investigated. The specific aim of this study was to assess the efficacy of ovarian tissue cyropreservation (OTC) in young females with cancer by evaluating its impact on FD.

METHODS

An IRB approved prospective human and animal trial enrolled girls (ages 6-18 years) with cancer at high risk for POF from July 1, 2012 through June 30, 2018. All participants underwent pre-operative ultrasounds evaluating their ovaries.  Following a normal ultrasound, each patient underwent a left ovarian tissue harvest prior to cancer therapy. The ovarian tissue was sectioned for use in pathologic analysis, fertility preservation and xenotransplantation before and after cryopreservation. Comparative statistical analyses of the means of FD before and after cryopreservation were implemented using mixed regression modeling that accounted for the correlation among samples from the same patient and differences in age.

RESULTS

Six girls were enrolled (mean, 12 years; median, 13 years, range, 6-17 years). Pathologic analysis was carried out in all viable grafts and ovarian follicle densities were determined. Mean ovarian follicle density (+/- SEM) before cryopreservation was 50.5 +/- 4.26 follicles/mm² and after cryopreservation was 44.1 +/- 4.25 follicles/mm², p < 0.001. Following cryopreservation, on average the ovarian tissue retained 89.0.% of the FD of paired fresh samples (95% CI 82.8%, 95.2%).

CONCLUSIONS

FD in young females with cancer is significantly reduced following OTC. However, the degree of reduction may be less than that reported in adult women. This is the first study in adolescent girls to provide histologic evidence of preservation of ovarian follicle density and potential efficacy of the ovarian tissue cryopreservation strategy.  By providing this evidence base, the potential benefit to young females with cancer and their family may be prognostically and clinically significant.

Adolescent Fertility Preservation: Where Do We Stand Now

Adolescence is a period of flux for many body systems. While fertility potential typically increases after menarche, there are diseases where the opposite occurs and fertility preservation options need to be considered early. In cases of cancer, options vary by pubertal status and can include ovarian tissue cryopreservation, oocyte cryopreservation, sperm cryopreservation, and testicular tissue cryopreservation. Much remains to be learned about fertility and preservation options in those with differences in sexual development (DSDs); however, depending on the form of DSD, fertility preservation may not be necessary. Similarly, traditional fertility counseling in children with galactosemia may need to be changed, as data suggest that fertility rates attributed to other causes of premature ovarian insufficiency may not be as applicable to this disease. Adolescents with Turner's syndrome are at high risk for premature ovarian failure; therefore, it is important to consider options as early as possible since ovarian reserves are depleted quickly. On the other hand, transgender and gender diverse adolescents may even be able to undergo fertility preservation after starting hormone therapy. In all cases, there are additional ethical components including technical/surgical risks in childhood, offering experimental therapies without creating false hope and evaluating children's consent and assent capabilities that must be considered.

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.

Ageing and chronic disease-related changes in the morphometric characteristics of ovarian follicles in cynomolgus monkeys (Macaca fascicularis)

STUDY QUESTION

How is the localisation of ovarian follicles affected by ageing and chronic diseases?

SUMMARY ANSWER

Ovarian follicles shift deeper towards the medulla, due to thickening of the tunica albuginea (TA), with ageing and some major common chronic diseases.

WHAT IS KNOWN ALREADY

The ovary undergoes morphological and functional changes with ageing. The follicular pool follows these changes with alterations in the amount and distribution of residual follicles. Diseases causing a chronic inflammatory process are associated with morphological changes and impaired ovarian function.

STUDY DESIGN, SIZE, DURATION

We conducted a cross-sectional study, examining 90 ovaries from 90 female monkeys. The samples were collected from April 2018 to March 2019 at Tsukuba Primate Research Center in National Institutes of Biomedical Innovation, Health and Nutrition, Japan.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovarian samples were obtained from cynomolgus monkeys that died from natural causes or were euthanised. Ovarian sections were stained with haematoxylin and eosin (H&E) for histological analyses. In ovarian sections from 64 female macaques aged 0-25 years, a total of 13 743 follicles at different developmental stages (primordial, intermediary, primary, early secondary and late secondary) were assessed to determine the depth of each follicle from the outer surface of the ovarian cortex to the far end of the follicle, by using a digital imaging software. TA thickness was measured as sum of basal membrane and tunica collagen layer for each ovary under H&E staining. To explore the possibility of age-related trends in ovarian morphometric characteristics, samples were divided into four different age groups (0-3 years (pre-menarche), 4-9 years, 10-14 years and 15-20 years). To evaluate the effect of common chronic diseases on ovarian morphometric characteristics, macaques with diabetes mellitus (DM) (n = 10), endometriosis (n = 8) or inflammatory bowel disease (IBD) (n = 8) were compared to age-matched controls without chronic diseases.

MAIN RESULTS AND THE ROLE OF CHANCE

Ovarian morphometric analysis revealed that the relative location of follicles became deeper in all age groups according to development of follicles (P < 0.05). Total follicle distance from the ovarian surface was increased with ageing (P < 0.05). In a sub-analysis according to developmental stage, only primordial and intermediary follicles were localised deeper with increasing age (P < 0.05). TA thickness was also increased with ageing (P < 0.05). The localisation of the total number of follicles became deeper in ovaries from monkeys with DM, endometriosis or IBD as compared to the control group (P < 0.05). With DM, analysis of follicles distance at almost each developmental stage was significantly deeper compared to controls (P < 0.05) with the exception of early secondary follicles. With endometriosis, follicles at primary and early and late secondary stages were significantly deeper compared to controls (P < 0.05). Also with IBD, follicles at primary and early and late secondary follicles were significantly deeper compared to controls (P < 0.001). The TA was thicker with DM and endometriosis compared to controls (P < 0.05), but not with IBD (P = 0.16).

LARGE SCALE DATA

NA.

LIMITATIONS, REASONS FOR CAUTION

Two-dimensional histology was used to assess follicle localisation. The possibility of minimal variations between the measured distance to the actual distance in a spherical structure cannot be excluded. Additionally, the severity of disease was not assessed.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first step towards enhancing our understanding of how ageing and chronic diseases affect the relative localisation of dormant and developing follicles. These observations, combined with possible future human studies, may have managerial implications in the field of fertility preservation and other conditions involving ovarian tissue cryopreservation.

STUDY FUNDING/COMPETING INTEREST(S)

The present work was supported by the Grant-in-Aid for Scientific Research B (19H03801) (to K.K.), Challenging Exploratory Research (18K19624), Japan Agency for Medical Research and Development, Mochida Memorial Foundation for Medical and Pharmaceutical Research, Takeda Science Foundation and Naito Foundation (to K.K.). All authors have no conflicts of interest directly relevant to the content of this article.

Applying plastic surgery principles to ovarian tissue transplantation

Ovarian tissue cryopreservation (OTC) and transplantation is an innovative procedure increasingly utilized to help preserve fertility after gonadotoxic treatments especially in cancer patients. Approximately 30% of autotransplanted patients are able to achieve live birth, typically with the help of in-vitro fertilization. Numerous techniques and grafting sites have been described to continue to increase this figure. In the field of plastic surgery, tissue grafting has been successful performed for thousands of years and knowledge in this area has been significantly refined. A qualitative review of the literature using PubMed, Cochrane, SCOPUS and Medline databases was performed to look for articles relating to ovarian tissue transplantation (OTT) and comparisons made to plastic surgery tissue grafting. Many parallels were found between the principles of grafting in plastic surgery and the principles of OTT, including pre-operative patient optimization, suitable donor site selection, tissue harvest and preparation, graft site choice, immobilization of the graft and post-operative care. Consideration of the benefits and risks of using orthotopic versus heterotopic recipient sites is also highly important with regards to graft take, morbidity and ease of access of oocyte collection. We believe that ongoing discussion between disciplines can have the potential to improve knowledge, surgical techniques and patient outcomes.

Comparison of open and a novel closed vitrification system with slow freezing for human ovarian tissue cryopreservation

PURPOSE

To investigate the differences concerning post-thawing/warming follicle survival, DNA damage and apoptosis in human ovarian tissues cryopreserved by slow freezing, open, or closed vitrification methods.

METHODS

A total of 50 pieces of 5 × 5 × 1 mm ovarian cortical pieces were harvested (5 donor ovaries; mean age 31 ± 6.62 years). From each donor, one cortical piece was used as baseline; the remaining were randomly assigned to slow freezing (SF), vitrification using open device (VF-open), or closed device (VF-closed) groups. After 8-10 weeks of cryostorage, tissues were evaluated 4 h after thawing/warming. Histological analysis was evaluated for follicle survival (primordial and primary follicle densities) by H&E staining. The percentages of primordial and primary follicles with DNA double-strand breaks (γH2AX) and apoptotic cell death pathway activation (AC3) were immunohistochemically assessed. Data were analysed using one-way ANOVA and LSD post hoc comparison.

RESULTS

Compared to the baseline, primordial follicle (pdf) densities significantly declined in all cryopreserved groups (SF, VF-open, and VF-closed, P < 0.05). However, the total and non-apoptotic pdf densities were similar among SF, VF-open, and VF-closed. SF and VF with either open or closed devices did not increase the percentages of primordial or primary follicles with DNA double-strand breaks (DSBs) or apoptosis compared to the baseline or among the freezing methods in the present study.

CONCLUSION

Based on the intact primordial follicle survival, DNA damage, and apoptosis rates after thawing/warming, SF vs VF with either open or newly developed closed devices appear to be comparable.

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.

Ovarian tissue grafting: Lessons learnt from our experience with 55 grafts

Purpose

Uncertainties remain regarding the clinical efficacy of ovarian tissue cryopreservation and grafting. We report a retrospective analysis of reproductive outcomes and lessons learnt following 55 ovarian tissue transplant procedures at our center from 2006 to 2019.

Methods

We analyzed variables related to graft success such as tissue volume, follicular density, total follicular volume, and age on the duration of graft function.

Results

Follicular density and total follicular volume correlate positively with duration of graft function. All clinical pregnancies in our cohort occurred in women who were aged 35 or less at the time of ovarian tissue cryopreservation.

Conclusion

Graft success, as determined by eventual pregnancy and the longevity of graft function, may be impacted by factors including age at cryopreservation, follicular density, and total follicular volume.

Ovarian tissue cryopreservation and transplantation in patients with central nervous system tumours

STUDY QUESTION

Is there a possibility of reseeding cancer cells potentially present in frozen ovarian tissue from patients with central nervous system (CNS) tumours?

SUMMARY ANSWER

Malignancy reseeding in cryopreserved ovarian tissue from 20 patients with CNS tumours was not detected by histology, immunohistochemistry (IHC), molecular biology or xenotransplantation.

WHAT IS KNOWN ALREADY

Ovarian metastasis potential has been documented in patients with leukaemia, borderline ovarian tumours, advanced breast cancer and Ewing sarcoma. However, data on the safety of transplanting frozen-thawed ovarian tissue from cancer patients with CNS tumours are still lacking.

STUDY DESIGN, SIZE, DURATION

This prospective experimental study was conducted in an academic gynaecology research laboratory using cryopreserved ovarian cortex from 20 patients suffering from CNS tumours. Long-term (5 months) xenografting was performed in immunodeficient mice.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Subjects enrolled in the study were suffering from one of six types of CNS tumours including medulloblastoma, ependymoma, primitive neuroectodermal tumours, astrocytoma, glioblastoma and germinoma. The presence of malignant cells was investigated with disease-specific markers for each patient in cryopreserved and xenografted ovarian tissue by histology, IHC via expression of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP), and reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) for quantification of GFAP and ENO2 gene amplification.

MAIN RESULTS AND THE ROLE OF CHANCE

Serial sections of cryopreserved and xenografted ovarian tissue from 20 patients showed no malignant cells by histology. All samples were negative for NSE and GFAP, although these neural markers were expressed extensively in the patients' primary tumours. Analysis by RT-ddPCR revealed no cancer cells detected in cryopreserved and xenografted ovarian fragments from subjects with astrocytoma, ependymoma, glioblastoma or medulloblastoma. Taken together, the study found no evidence of malignancy seeding in frozen-thawed and xenotransplanted ovarian tissue from patients affected by CNS cancers.

LIMITATIONS, REASONS FOR CAUTION

This analysis cannot guarantee complete elimination of disseminated disease from all cryopreserved ovarian cortex, since we are unable to examine the fragments used for transplantation.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to be conducted in patients with CNS cancers undergoing ovarian tissue cryopreservation and transplantation, and clearly demonstrates no tumour seeding in their frozen-thawed and xenografted tissue. This information is vital for doctors to provide patients with meaningful and accurate advice on the possibilities and risks of ovarian tissue reimplantation.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique-the Excellence of Science (FNRS-EOS), number 30443682 awarded to M.-M.D. and T.Y.T.N., FNRS grant number 5/4/150/5 and FNRS-PDR Convention grant number T.0077.14 awarded to M.-M.D., grant 2018-042 from the Foundation Against Cancer awarded to A.C., and private donations (Ferrero, de Spoelberch). The authors declare no competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Modulating hypoxia and oxidative stress in human xenografts using adipose tissue-derived stem cells

OBJECTIVE

To investigate whether adipose tissue-derived stem cells (ASCs) modulate hypoxia and oxidative stress in human ovarian tissue transplants.

DESIGN

Prospective experimental study SETTING: Gynecological research unit in a university hospital PATIENT(S): Cryopreserved ovarian cortex from 5 adult women.

INTERVENTION(S)

Thirty mice were grafted with frozen-thawed human ovarian tissue, with or without ASCs (2-step/ASCs+ovarian tissue [OT] group and OT group). The ovarian grafts were retrieved on days 3 (n = 5), 10 (n = 5), and 21 (n = 5). The 10 animals grafted for 21 days underwent in vivo evaluations using microdialysis. One piece of ovarian tissue per patient was fixed for analysis after thawing (non-grafted controls).

MAIN OUTCOME MEASURE(S)

Direct reactive oxygen species were collected every second day after grafting by means of microdialysis. Analyses of ovarian fragments included immunolabeling for double CD34 (revascularization by host and graft components); immunofluorescence for hypoxia-inducible factor 1α (hypoxia-related response), nuclear factor erythroid 2-related factor 2 (oxidative stress-related response), and 8-hydroxy-deoxyguanosine (oxidative stress-related DNA damage); and gene expression (quantitative reverse transcription polymerase chain reaction) for vascular endothelial growth factor-A (neoangiogenesis), superoxide dismutase 2 (antioxidant activity), and nuclear respiratory factor 1 (mitochondrial biogenesis).

RESULT(S)

Reactive oxygen species peaked earlier in the ASC group (day 2) compared with that in the OT group (day 10) after grafting. Total vascularization was stable in the ASC group at all time points, while it was lower in the OT group 3 days after grafting. Hypoxia-inducible factor 1α expression, also detected in non-grafted controls, was significantly lower in the ASC group than in the OT group on days 3 and 10. The increase in VEGF gene expression lasted significantly longer in the ASC group than in the OT group. There was no significant upturn in the oxidative stress-related response (nuclear factor erythroid 2-related factor 2 pathway) or oocyte DNA damage (8-hydroxy-deoxyguanosine) in any of the grafted groups.

CONCLUSION(S)

Use of ASCs allows faster ovarian graft reperfusion and mitigates the hypoxia-related response through rapid revascularization, sustained by prolonged increase in vascular endothelial growth factor after grafting. No evidence of oxidative stress-related damage was detected irrespective of the transplantation strategy.

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.

Hot Topics on Fertility Preservation for Women and Girls-Current Research, Knowledge Gaps, and Future Possibilities

Fertility preservation is a novel clinical discipline aiming to protect the fertility potential of young adults and children at risk of infertility. The field is evolving quickly, enriched by advances in assisted reproductive technologies and cryopreservation methods, in addition to surgical developments. The best-characterized target group for fertility preservation is the patient population diagnosed with cancer at a young age since the bulk of the data indicates that the gonadotoxicity inherent to most cancer treatments induces iatrogenic infertility. Since improvements in cancer therapy have resulted in increasing numbers of long-term survivors, survivorship issues and the negative impact of infertility on the quality of life have come to the front line. These facts are reflected in an increasing number of scientific publications referring to clinical medicine and research in the field of fertility preservation. Cryopreservation of gametes, embryos, and gonadal tissue has achieved quality standards for clinical use, with the retrieval of gonadal tissue for cryopreservation being currently the only method feasible in prepubertal children. Additionally, the indications for fertility preservation beyond cancer are also increasing since a number of benign diseases and chronic conditions either require gonadotoxic treatments or are associated with premature follicle depletion. There are many remaining challenges, and current research encompasses clinical health care and caring sciences, ethics, societal, epidemiological, experimental studies, etc.

In vitro growth and maturation of primordial follicles and immature oocytes

Cryopreservation of ovarian tissue to preserve the fertility of girls and young women at high risk of sterility is now widely practiced. Pieces of cryopreserved ovarian cortex can be thawed and autografted to restore fertility, but because of the risks of reintroduction of the cancer, transplantation may not be possible for girls and women with blood-borne leukemias or cancers with a high risk of ovarian metastasis. Cryopreserved ovarian tissue contains mainly primordial follicles but also provides access to immature oocytes from small antral follicles, which may be matured in vitro to provide an additional source of mature oocytes. So in cases in which transplantation is contraindicated, fertility restoration could be safely achieved in the laboratory either by in vitro maturation (IVM) of oocytes aspirated from growing follicles or by the complete in vitro growth (IVG) and maturation (IVM) of primordial follicles to produce fertile metaphase II (MII) oocytes. The development of IVM and IVG methods to support all stages of oocytes available within ovarian tissue will maximize the potential for all patients undergoing fertility preservation.