Transplantation of cryopreserved ovarian tissue in a series of 285 women: a review of five leading European centers

Ovarian Tissue Cryopreservation in Children and Adolescents

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

A synopsis of the 2021 International Society of Fertility Preservation bi-annual meeting

On November 19, 2021, the first virtual meeting of the International Society for Fertility Preservation (ISFP) took place. Eight experts in the field of reproductive medicine presented important updates on their research in the field of fertility preservation and reproductive surgery for absolute uterine factor infertility. Presentations included talks on ovarian stem cell therapy for premature ovarian insufficiency, practical aspects of oocyte vitrification, ovarian stimulation for patients with breast cancer, in vitro maturation of oocytes at the time of ovarian tissue harvesting, male fertility preservation, and uterine transplantation. These presentations are summarized below and can be viewed in their entirety at www.isfp-fertility.org.

The current and future state of surgery in reproductive endocrinology

PURPOSE OF REVIEW

The last decade has witnessed a radical change in the field of reproductive surgery. The increasing success of in-vitro fertilization (IVF) has caused a huge shift in emphasis with many downstream consequences. This review outlines the changes and provides insight into the future of reproductive surgery.

RECENT FINDINGS

With compelling evidence that IVF overcomes the detrimental effects of endometriosis on infertility and with two new oral medications available for management of endometriosis, momentum is shifting towards nonsurgical management of endometriosis. There is increasing recognition that except for submucous myomas, other myomas are unlikely to affect fertility and miscarriage. This, in addition to many emerging alternative modalities for management of myomas (oral GnRH antagonists, radiofrequency ablation), is likely to further decrease classic myomectomies but provide alternative, less invasive options. Caesarean scar defects have been recognized as having significant reproductive consequences and surgical management has become the standard of care. Fallopian tubes are now implicated in development of ovarian cancer, and as a result, salpingectomies are being performed in lieu of tubal ligations. Tubal anastomosis will soon become a historical surgery. Division of uterine septum remains controversial, and a clear answer will remain elusive. Uterine transplant is the single most significant advance in reproductive surgery in the past century.

SUMMARY

Reproductive surgery is evolving with the times. Although some surgical techniques will become historical, others will become mainstream.

A synopsis of global frontiers in fertility preservation

Since 2007, the Oncofertility Consortium Annual Conference has brought together a diverse network of individuals from a wide range of backgrounds and professional levels to disseminate emerging basic and clinical research findings in fertility preservation. This network also developed enduring educational materials to accelerate the pace and quality of field-wide scientific communication. Between 2007 and 2019, the Oncofertility Consortium Annual Conference was held as an in-person event in Chicago, IL. The conference attracted approximately 250 attendees each year representing 20 countries around the world. In 2020, however, the COVID-19 pandemic disrupted this paradigm and precluded an in-person meeting. Nevertheless, there remained an undeniable demand for the oncofertility community to convene. To maintain the momentum of the field, the Oncofertility Consortium hosted a day-long virtual meeting on March 5, 2021, with the theme of "Oncofertility Around the Globe" to highlight the diversity of clinical care and translational research that is ongoing around the world in this discipline. This virtual meeting was hosted using the vFairs ® conference platform and allowed over 700 people to participate, many of whom were first-time conference attendees. The agenda featured concurrent sessions from presenters in six continents which provided attendees a complete overview of the field and furthered our mission to create a global community of oncofertility practice. This paper provides a synopsis of talks delivered at this event and highlights the new advances and frontiers in the fields of oncofertility and fertility preservation around the globe from clinical practice and patient-centered efforts to translational research.

Fertility preservation practices for female oncofertility differ significantly across the USA: results of a survey of SREI members

PURPOSE

The field of oncofertility has maintained an important focus on improving access, yet standardized practices are lacking. To assess how female cancer patients are provided oncofertility care, we sought to determine provider-level differences and whether there are physician or practice characteristics that predict these variations.

METHODS

A cross-sectional survey was sent to SREI members. The survey included fifteen questions about physician practice characteristics and oncofertility cryopreservation protocols. Topics included ovarian stimulation protocols, fertilization techniques, stage of embryo cryopreservation, routine use of pre-implantation genetic testing for aneuploidy (PGT-A), and ovarian tissue cryopreservation (OTC). Statistical analyses assessed whether practice setting, geographic region, time in practice, and mandatory state insurance coverage had effects on cryopreservation protocols.

RESULTS

A total of 141 (17%) from diverse REI practice backgrounds completed the survey. The median number of new female oncofertility consults per year was 30 (range 1 to 300). Providers in academic settings treated more patients (median 40 vs. 15, p < 0.001). Providers in academic settings more often use gonadotropin-releasing hormone agonists (85% vs. 52%, p < 0.001) and perform OTC (41% vs. 4%, p < 0.001). Providers in academic practices were less likely to perform intracytoplasmic sperm injection in every cycle (37% vs. 55%, p = 0.032) and less likely to usually advise PGT-A (21% vs. 36%, p = 0.001). Mandated state insurance coverage had no effect on oncofertility practices.

CONCLUSION

Oncofertility practices vary among providers. Factors such as practice setting and region may affect the services provided. We do not yet know the best practices in oncofertility patients, and future research is needed.

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.

Identification of Biomarkers for Predicting Ovarian Reserve of Primordial Follicle via Transcriptomic Analysis

Ovarian reserve (OR) is mainly determined by the number of primordial follicles in the ovary and continuously depleted until ovarian senescence. With the development of assisted reproductive technology such as ovarian tissue cryopreservation and autotransplantation, growing demand has arisen for objective assessment of OR at the histological level. However, no specific biomarkers of OR can be used effectively in clinic nowadays. Herein, bulk RNA-seq datasets of the murine ovary with the biological ovarian age (BOA) dynamic changes and single-cell RNA-seq datasets of follicles at different stages of folliculogenesis were obtained from the GEO database to identify gene signature correlated to the primordial follicle pool. The correlations between gene signature expression and OR were also validated in several comparative OR models. The results showed that genes including Lhx8, Nobox, Sohlh1, Tbpl2, Stk31, and Padi6 were highly correlated to the OR of the primordial follicle pool, suggesting that these genes might be used as biomarkers for predicting OR at the histological level.

Ovarian Stem Cells (OSCs) from the Cryopreserved Ovarian Cortex: A Potential for Neo-Oogenesis in Women with Cancer-Treatment Related Infertility: A Case Report and a Review of Literature

Cancer treatment related infertility (CTRI) affects more than one third of young women undergoing anti-cancer protocols, inducing a premature exhaustion of the ovarian reserve. In addition to ovarian suppression by GnRHa, oocyte and cortex cryopreservation has gained interest in patients with estrogen-sensitive tumors for whom the hormonal burst to prompt the multiple follicular growth could provide a further pro-life tumor pulsing. On the other hand, cortex reimplantation implies a few drawbacks due to the unknown consistency of the follicles to be reimplanted or the risk of reintroducing malignant cells. The capability of ovarian stem cells (OCSs) from fresh ovarian cortex fragments to differentiate in vitro to mature oocytes provides a tool to overcome these drawbacks. In fact, since ovarian cortex sampling and cryopreservation is practicable before gonadotoxic treatments, the recruitment of OSCs from defrosted fragments could provide a novel opportunity to verify their suitability to be expanded in vitro as oocyte like cells (OLCs). Here, we describe in very preliminary experiments the consistency of an OSC population from a single cryopreserved ovarian cortex after thawing as well as both their viability and their suitability to be further explored in their property to differentiate in OLCs, thus reinforcing interest in stemness studies in the treatment of female CTRI.

First live birth in China after cryopreserved ovarian tissue transplantation to prevent premature ovarian insufficiency

OBJECTIVE

This article reports the first live birth after cryopreserved ovarian tissue transplantation to prevent premature ovarian insufficiency in China.

METHODS

A patient with myelodysplastic syndrome received ovarian tissue cryopreservation before hematopoietic stem cell transplantation, and six ovarian cortex strips were thawed and transplanted into her peritoneal pocket 2 years later.

RESULTS

Pregnancy occurred spontaneously 27 months after grafting, and a healthy girl was born at 38 weeks gestation. Until now, the child has developed normally without any major diseases.

CONCLUSIONS

We report the first live birth resulting from ovarian tissue cryopreservation and transplantation in China.

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.

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.

Quantification of residual cryoprotectants and cytotoxicity in thawed bovine ovarian tissues after slow freezing or vitrification

STUDY QUESTION

How much residual cryoprotectant remains in thawed/warmed ovarian tissues after slow freezing or vitrification?

SUMMARY ANSWER

After thawing/warming, at least 60 min of diffusion washing in media was necessary to significantly reduce the residual cryoprotectants in ovarian tissues frozen by slow freezing or vitrification.

WHAT IS KNOWN ALREADY

Ovarian tissue cryopreservation (OTC) by slow freezing has been the conventional method; while the vitrification method has gained popularity for its practicality. The main concern about vitrification is how much potentially toxic residual cryoprotectant remains in the warmed tissues at the time of transplantation.

STUDY DESIGN, SIZE, DURATION

This was an animal study using the ovarian tissues from 20 bovine ovaries. The duration of this study was from 2018 to 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovarian cortex tissues were prepared from 20 bovine ovaries and assigned randomly to groups of fresh (non-frozen) control, slow freezing with 1.5 M dimethyl sulfoxide (DMSO), 1.5 M 1,2-propanediol (PROH) and vitrification with 35% ethylene glycol (EG). The residual cryoprotectant concentrations in thawed/warmed tissues were measured by gas chromatography at the following time points: frozen (before thawing/warming), 0 min (immediately after thawing/warming), 30, 60 and 120 min after diffusion washing in media. Next, the ultrastructural changes of primordial follicles, granulosa cells, organelles and stromal cells in the ovarian tissues (1 mm × 1 mm × 1 mm) were examined in fresh (non-frozen) control, slow freezing with DMSO or PROH and vitrification with EG groups. Real-time quantitative PCR was carried out to examine the expressions of poly (ADP-ribose) polymerase-1 (PARP1), a DNA damage sensor and caspase-3 (CASP3), an apoptosis precursor, in thawed/warmed ovarian tissues that were washed for either 0 or 120 min and subsequently in tissues that were ex vivo cultured for 24 or 48 h. The same set of tissues were also used to analyze the protein expressions of gamma H2A histone family member X (γH2AX) for DNA double-strand breaks and activated caspase-3 (AC3) for apoptosis by immunohistochemistry.

MAIN RESULTS AND THE ROLE OF CHANCE

The residual cryoprotectant concentrations decreased with the extension of diffusion washing time. After 60 min washing, the differences of residual cryoprotectant between DMSO, PROH and EG were negligible (P > 0.05). This washing did not affect the tissue integrity or significantly elevate the percentage of AC3 and γH2AX positive cells, indicating that tissues are safe and of good quality for transplantation.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Since the study was performed with ovarian tissues from bovines, generalizability to humans may be limited. Potential changes in ovarian tissue beyond 120 min were not investigated.

WIDER IMPLICATIONS OF THE FINDINGS

This study addresses concerns about the cytotoxicity of EG in warmed ovarian tissues and could provide insights when devising a standard vitrification protocol for OTC.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by a Grant-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science to N.S.

Cost-effectiveness analysis of ovarian tissue cryopreservation and transplantation for preservation of fertility in post-pubertal oncological women submitted to high-risk gonadotoxic chemotherapy

OBJECTIVE

To study the economic impact of ovarian tissue cryopreservation and transplantation (OTC) in post-pubertal patients who underwent high-risk gonadotoxic chemotherapy.

METHODS

A decision tree model was used to determine the live birth rate and cost-effectiveness of OTC versus non-OTC. The incremental cost-effectiveness ratio (ICER) was calculated. A sensitivity analysis was performed under the assumption that the costs of ovarian cortex retrieval, cryopreservation, and storage for patients with cancer might be covered by the national health system or health insurance.

RESULTS

Patients had the greatest probability of achieving live birth after high-risk chemotherapy when they underwent OTC versus non-OTC. Although cryopreservation of ovarian tissue results in higher live birth rates, it is always more expensive. Cost-effectiveness increases when the majority of patients completes the path of tissue cryopreservation plus transplantation after 5 years.

CONCLUSION

Although OCT has been demonstrated as a procedure for effective fertility preservation in fertility-age women with cancer, no cost-effectiveness analysis has been performed until now. This model could help healthcare systems to allocate coverage for OCT.

Effect of Previous Alkylating Agent Exposure on Follicle Numbers in Cryopreserved Prepubertal and Young Adult Ovarian Tissue after Long-Term Xenografting

Simple Summary

Cryopreservation of ovarian tissue is a promising technique for fertility preservation in cancer patients at increased risk for subfertility. The International Guideline Harmonization Group recommends ovarian tissue cryopreservation for children and young adults before therapy with cumulative doses of alkylating agent at or above 6000–8000 mg/m². A therapy that poses a high risk of subfertility is rarely the first-line therapy and many of the patients have already undergone several regimens of chemotherapy. The aim of our study was to assess the effects of chemotherapy exposures on the quality of cryopreserved ovarian tissue. We confirmed the harmful effects of alkylating agents on xenografted ovarian tissue and suggest that cumulative doses which are not regarded as an indication for fertility preservation in children and young adult may decrease the quality of cryopreserved follicles.

Abstract

Purpose and methods: To elucidate whether previous cancer treatment affects graft recovery and follicle numbers, morphology, and development in grafts, cryopreserved ovarian biopsies obtained from 18 cancer patients aged 1–24 years with and without exposure to chemotherapy were xenografted as 1 mm³ fragments to immunodeficient mice for 22 weeks with exogenous stimulation. Results: Graft recovery showed no association with chemotherapy exposure, pubertal stage, or leukemia contamination. Total follicle number per recovered graft varied between 0 and 1031 in the chemotherapy-exposed and between 0 and 502 in the non-chemotherapy-exposed group. Atretic follicles formed the largest proportion of the follicle pool in chemotherapy-exposed grafts. Increased atresia correlated with exposure to alkylating agents (mean ± SD 8866.2 ± 9316.3 mg/m²) but not with anthracyclines, pubertal stage, or leukemia contamination. Conclusion: The observation confirms the harmful effects of alkylating agents on ovarian tissue. Therapy at the median cumulative dose of 8866 mg/m² leads to the decreased quality of cryopreserved ovarian follicles in children and young adults.

Fertility preservation for pediatric patients with hemoglobinopathies: Multidisciplinary counseling needed to optimize outcomes

Hemoglobinopathies are autosomal recessive disorders that occur when genetic mutations negatively impact the function of hemoglobin. Common hemoglobinopathies that are clinically significant include sickle cell disease, alpha thalassemia, and beta thalassemia. Advancements in disease-modifying and curative treatments for the common hemoglobinopathies over the past thirty years have led to improvements in patient quality of life and longevity for those who are affected. However, the diseases, their treatments and cures pose infertility risks, making fertility preservation counseling and treatment an important part of the contemporary comprehensive patient care. Sickle cell disease negatively impacts both male and female infertility, primarily by testicular failure and decreased ovarian reserve, respectively. Fertility in both males and females with beta thalassemia major are negatively impacted by iron deposition due to chronic blood transfusions. Hematopoietic stem cell transplant (HSCT) is currently the only curative treatment for SCD and transfusion dependent beta thalassemia. Many of the conditioning regimens for HSCT contain chemotherapeutic agents with known gonadotoxicity and whole-body radiation. Although most clinical studies on toxicity and impact of HSCT on long-term health do not evaluate fertility, gonadal failure is common. Male fertility preservation modalities that exist prior to gonadotoxic treatment include sperm banking for pubertal males and testicular cryopreservation for pre-pubertal boys. For female patients, fertility preservation options include oocyte cryopreservation and ovarian tissue cryopreservation. Oocyte cryopreservation requires controlled ovarian hyperstimulation (COH) with ten to fourteen days of intensive monitoring and medication administration. This is feasible once the patient has undergone menarche. Follicular growth is monitored via transvaginal or transabdominal ultrasound, and hormone levels are monitored through frequent blood work. Oocytes are then harvested via a minimally invasive approach under anesthesia. Complications of COH are more common in patients with hemoglobinopathies. Ovarian hyperstimulation syndrome creates a greater risk to patients with underlying vascular, pulmonary, and renal injury, as they may be less able to tolerate fluids shifts. Thus, it is critical to monitor patients undergoing COH closely with close collaboration between the hematology team and the reproductive endocrinology team. Counseling patients and families about future fertility must take into consideration the patient's disease, treatment history, and planned treatment, acknowledging current knowledge gaps.

Ovarian tissue cryopreservation for a 3-year-old girl with Mosaic Turner syndrome in China: First case report and literature review

BACKGROUND

Although it cannot be predicted accurately which young females will develop premature ovarian insufficiency (POI) following chemotherapy or irradiation, patients at high risk of POI should be offered ovarian tissue cryopreservation (OTC). Our ovarian tissue cryobank is the first center in China. OTC was firstly performed on a 3-year-old girl with mosaic Turner syndrome (TS) in China. We report this case and present a literature review about TS girls' fertility preservation (FP).

CASE PRESENTATION

Karyotype analysis of umbilical cord blood showed that the girl was diagnosed with TS, 45,X [19]/46,XX [81]. The girl was a 3-year-old girl when her parents would like OTC to preserve fertility. No abnormality was found in the reproductive system, abdominal and cardiac ultrasound, spinal X-ray, and bone age. She was treated with growth hormone (GH) one year ago because of her short stature. GH has been discontinued now. Because of the high risk of POI, OTC was planned. The hormone level before OTC was FSH 4.27 IU/L, LH 0.00 IU/L, E2 < 11.80 pg/ml, AMH 1.06 ng/ml. Pelvic ultrasound showed that the size of the bilateral ovaries was 1.6 cm×0.7-0.8 cm, no enlarged follicles were found, and the maximum diameter of follicles was 0.2-0.37 cm. Ovarian tissue for OTC was taken from the whole right ovary by laparoscopic surgery, and the antral follicles could be seen in ovarian tissue preparation. Sixteen ovarian cortical slices were cryopreserved by slow freezing, with an average of 1380 follicles in round cortical tissue with a diameter of 2 mm, and the follicular density was about 440/mm³. The ovarian tissue from 10 children with non-TS was cryopreserved in our center, the median age was 5 (range 2-8) years old, and the median number of follicles was 766 (range 163-2250) per 2 mm biopsy. The follicles number in this girl were within normal range.

CONCLUSION

TS patients should be evaluated early in childhood to benefit from FP. For highly selected young females with mosaic TS, if the endocrine evaluation does not indicate POI and other health problems do not rule out future pregnancy, it seems reasonable to consider OTC as an FP option.

Aging conundrum: A perspective for ovarian aging

Progressive loss of physiological integrity and accumulation of degenerative changes leading to functional impairment and increased susceptibility to diseases are the main features of aging. The ovary, the key organ that maintains female reproductive and endocrine function, enters aging earlier and faster than other organs and has attracted extensive attention from society. Ovarian aging is mainly characterized by the progressive decline in the number and quality of oocytes, the regulatory mechanisms of which have yet to be systematically elucidated. This review discusses the hallmarks of aging to further highlight the main characteristics of ovarian aging and attempt to explore its clinical symptoms and underlying mechanisms. Finally, the intervention strategies related to aging are elaborated, especially the potential role of stem cells and cryopreservation of embryos, oocytes, or ovarian tissue in the delay of ovarian aging.

OUP accepted manuscript

BACKGROUND

To provide the optimal milieu for implantation and fetal development, the female reproductive system must orchestrate uterine dynamics with the appropriate hormones produced by the ovaries. Mature oocytes may be fertilized in the fallopian tubes, and the resulting zygote is transported toward the uterus, where it can implant and continue developing. The cervix acts as a physical barrier to protect the fetus throughout pregnancy, and the vagina acts as a birth canal (involving uterine and cervix mechanisms) and facilitates copulation. Fertility can be compromised by pathologies that affect any of these organs or processes, and therefore, being able to accurately model them or restore their function is of paramount importance in applied and translational research. However, innate differences in human and animal model reproductive tracts, and the static nature of 2D cell/tissue culture techniques, necessitate continued research and development of dynamic and more complex in vitro platforms, ex vivo approaches and in vivo therapies to study and support reproductive biology. To meet this need, bioengineering is propelling the research on female reproduction into a new dimension through a wide range of potential applications and preclinical models, and the burgeoning number and variety of studies makes for a rapidly changing state of the field.

OBJECTIVE AND RATIONALE

This review aims to summarize the mounting evidence on bioengineering strategies, platforms and therapies currently available and under development in the context of female reproductive medicine, in order to further understand female reproductive biology and provide new options for fertility restoration. Specifically, techniques used in, or for, the uterus (endometrium and myometrium), ovary, fallopian tubes, cervix and vagina will be discussed.

SEARCH METHODS

A systematic search of full-text articles available in PubMed and Embase databases was conducted to identify relevant studies published between January 2000 and September 2021. The search terms included: bioengineering, reproduction, artificial, biomaterial, microfluidic, bioprinting, organoid, hydrogel, scaffold, uterus, endometrium, ovary, fallopian tubes, oviduct, cervix, vagina, endometriosis, adenomyosis, uterine fibroids, chlamydia, Asherman’s syndrome, intrauterine adhesions, uterine polyps, polycystic ovary syndrome and primary ovarian insufficiency. Additional studies were identified by manually searching the references of the selected articles and of complementary reviews. Eligibility criteria included original, rigorous and accessible peer-reviewed work, published in English, on female reproductive bioengineering techniques in preclinical (in vitro/in vivo/ex vivo) and/or clinical testing phases.

OUTCOMES

Out of the 10 390 records identified, 312 studies were included for systematic review. Owing to inconsistencies in the study measurements and designs, the findings were assessed qualitatively rather than by meta-analysis. Hydrogels and scaffolds were commonly applied in various bioengineering-related studies of the female reproductive tract. Emerging technologies, such as organoids and bioprinting, offered personalized diagnoses and alternative treatment options, respectively. Promising microfluidic systems combining various bioengineering approaches have also shown translational value.

WIDER IMPLICATIONS

The complexity of the molecular, endocrine and tissue-level interactions regulating female reproduction present challenges for bioengineering approaches to replace female reproductive organs. However, interdisciplinary work is providing valuable insight into the physicochemical properties necessary for reproductive biological processes to occur. Defining the landscape of reproductive bioengineering technologies currently available and under development for women can provide alternative models for toxicology/drug testing, ex vivo fertility options, clinical therapies and a basis for future organ regeneration studies.

Analysis of Fertility Preservation by Ovarian Tissue Cryopreservation in Pediatric Children in China

BACKGROUND

Ovarian tissue cryopreservation (OTC) is the only method of fertility preservation (FP) in prepubertal girls, but the experience remains limited. This study investigates the effectiveness and feasibility of FP of OTC in children facing gonadotoxicity treatment in Chinese first ovarian tissue cryobank.

PROCEDURE

OTC and evaluation of 49 children ≤14 years old in the cryobank of Beijing Obstetrics and Gynecology Hospital, Capital Medical University, from July 2017 to May 19, 2022, were analyzed retrospectively. We compared children's general characteristics, follicle numbers, and hormone levels with and without chemotherapy before OTC.

RESULTS

The age of 49 children at the time of OTC was 7.55 (1-14) years old. There were 23 cases of hematological non-malignant diseases, eight cases of hematological malignant diseases, four cases of gynecological malignant tumors, one case of neurological malignant tumors, one case of bladder cancer, five cases of sarcoma, three cases of mucopolysaccharidosis, one case of metachromatic leukodystrophy, two cases of dermatomyositis, one case of Turner's syndrome. The median follicular count per 2-mm biopsy was 705. Age and AMH were not correlated (r = 0.084, P = 0.585). Age and follicle count per 2-mm biopsy was not correlated (r = -0.128, P = 0.403). Log10 (follicle count per 2-mm biopsy) and Log10 (AMH) were not correlated (r = -0.118, P = 0.456). Chemotherapy before OTC decreased AMH levels but had no significant effect on the number of follicles per 2-mm biopsy.

CONCLUSIONS

OTC is the only method to preserve the fertility of prepubertal girls, and it is safe and effective. Chemotherapy before OTC is not a contraindication to OTC.

Learning curve of surgeons performing laparoscopic ovarian tissue transplantation in women with premature ovarian insufficiency: A statistical process control analysis

STUDY OBJECTIVE

To analyze patient safety in laparoscopic ovarian tissue transplantation surgery by tracking the rate of postoperative complications and the learning curves of the surgeons by statistical process control (SPC) analysis.

DESIGN

A retrospective study.

SETTING

A university-affiliated hospital.

PATIENTS

One hundred patients with premature ovarian insufficiency (POI) who underwent ovarian tissue cryopreservation by vitrification and then autologous transplantation of frozen-thawed ovarian tissues with in vitro activation (IVA).

INTERVENTION

Ovarian tissue cryopreservation, in vitro activation and transplantation.

MEASUREMENTS AND MAIN RESULTS

We assessed the surgery complications, differences in total surgery time, transplantation time, and transplantation time per ovarian sheet in operations performed by 3 experienced laparoscopic surgeons. Surgeon A performed 80 operations; surgeon B, 29 operations; and surgeon C, 20 operations. Complications occurred in 1.55% of the procedures. While all three surgeons' performance never fell below the unacceptable failure limit, only surgeon A became competent after 66 cases.

CONCLUSION

The laparoscopic ovarian tissue transplantation surgery was generally safe as the postoperative complications were infrequent (1.55%). Although the performance of all 3 surgeons was acceptable, only surgeon A attained the level of competency after 66 cases. The transplantation method may not be the key factor for reducing surgery time in this surgery. An efficient OTT team is more important in reducing the surgery time than the surgeon's surgical technique alone.

Anti-Müllerian hormone: A function beyond the Müllerian structures

The anti-Müllerian hormone (AMH) is a heterodimeric glycoprotein belonging to the TGFb superfamily implicated in human embryonic development. This hormone was first described as allowing regression of the epithelial embryonic Müllerian structures in males, which would otherwise differentiate into the uterus and fallopian tubes. It activates a signaling pathway mediated by two transmembrane receptors. Binding of AMH to its receptor induces morphological changes leading to the degeneration of Müllerian ducts. Recently, new data has shown the role played by this hormone on structures other than the genital tract. If testicular AMH expression decreases in humans over the course of a lifetime, synthesis may persist in other tissues in adulthood. The mechanisms underlying its production have been unveiled. The aim of this review is to describe the different pathways in which AMH has been identified and plays a pivotal role.

Ovarian tissue cryopreservation in a patient with breast cancer during pregnancy: a case report

BACKGROUND

Fertility preservation using ovarian tissue cryopreservation (OTC) in patients with certain diseases, especially those needing chemo- or radiotherapy, is becoming routine in various Western countries. Our hospital is the first and until now the only centre in China to use this method. The question of whether treatment of breast cancer during pregnancy (PrBC) should be similar to non-pregnant young patients with breast cancer is controversial. To our knowledge, this is the first report worldwide to use OTC as fertility preservation for PrBC.

CASE PRESENTATION

During the 29th week of pregnancy, a 24-year-old woman underwent needle aspiration cytology of a left breast tumour. Ultrasound and cytology revealed BI-RADS 4a grade. Oncologists recommended termination of the pregnancy. Caesarean section was performed at week 32, and ovarian tissue samples were collected for OTC to preserve fertility and ovarian endocrine function. Twenty-three ovarian cortex slices were cryopreserved. It is estimated that 13,000 follicles were cryopreserved. Breast nodules and sentinel lymph node biopsy suggested invasive micropapillary carcinoma. Neoadjuvant chemotherapy was started within 1 week after diagnosis. After six courses of neoadjuvant chemotherapy, targeted drug therapy and goserelin acetate, left mastectomy and left axillary lymph node dissection were performed. In total, 23 doses of radiotherapy, eight trastuzumab targeted therapy treatments, and 17 pertuzumab + trastuzumab double targeted therapy treatments were performed after breast cancer surgery. Until now, more than 2 years after delivery, the ovarian function still is good, and no signs of a negative impact of OTC have been observed. Goserelin acetate injections, administered every 28 days, are planned to last for the next 5 years. In addition, endocrine therapy with anastrozole was started after breast cancer surgery and also is scheduled for 5 years.

CONCLUSION

OTC for fertility preservation in patients with PrBC does not delay breast surgery, radiotherapy or chemotherapy, which is essential for effective treatment of breast cancer. We assess this method as a promising fertility preservation method which was used here for the first time worldwide in a patient who developed breast cancer during pregnancy.

The effect of different vitrification protocols on cell survival in human ovarian tissue: a pilot study

Background

Vitrification has superseded the slow freezing method for cryopreservation of oocytes, embryos, and sperm, but there are as yet no standard protocols for its use in ovarian tissue cryopreservation (OTC). Published protocols diverge mainly with regard to the extent of supplementation of dimethyl sulfoxide (DMSO) to the vitrification medium, and to the use of an open or closed vitrification system.

We investigated the viability of cells after vitrification/warming, using ovarian tissue of transgender patients, by means of Fluorescence Activated Cells Sorting (FACS), and histomorphological analyses using a DMSO-containing (P1) and a DMSO-free protocol (P2) in an open or closed vitrification setting.

Results

Twelve ovarian samples were donated from female-to-male transgender patients: 6 were vitrified according to protocol 1, the other 6 according to protocol 2. The amount of viable cells was 90.1% (P1) and 88.4% (P2) before vitrification. After vitrification and subsequent warming, viable cells were reduced to 82.9% (P1, p = 0.093) and 72.4% (P2, p = 0.019). When comparing the closed and the open systems, the decline in cell viability from pre- to post-vitrification was significant only for the latter (p = 0.037). Histological examination reveals no significant differences with respect to degenerated follicles before or after vitrification.

Conclusion

These results led us to conclude that a protocol containing DMSO results in a higher viability of ovarian cells than a protocol that uses ethylene glycol as cryoprotective agent in vitrification. The use of an open vitrification system led to significant decline in the rate of viable cells.

Trial registration

NCT03649087, retrospectively registered 28.08.2018.

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

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

Ovarian tissue and oocyte cryopreservation prior to iatrogenic premature ovarian insufficiency

Gonadotoxic treatments like chemotherapy or radiotherapy and ovarian surgery may result in an accelerated depletion of the ovarian reserve and subsequent premature ovarian insufficiency. Important determinants of this severe risk that require fertility preservation strategies are patient age, ovarian reserve, type of treatment, and administered dose. Oocytes and ovarian tissue can both be cryopreserved, with encouraging results in terms of pregnancy and live birth rates according to recent publications. Moreover, since ovarian tissue transplantation also results in long-term endocrine resumption, it represents a potential future therapeutic option for complete ovarian function restoration in patients with premature ovarian insufficiency.

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

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

Hormonal Characteristics of Women Receiving Ovarian Tissue Transplantation with or without Endogenous Ovarian Activity

Ovarian tissue cryopreservation (OTC) and transplantation of frozen/thawed ovarian tissue (OTT) are used for fertility preservation in girls and women. Here, we evaluated the hormonal characteristics of women with or without postmenopausal levels of FSH at the time of OTT to study differences and conditions that best support the initiation of ovarian function. A total of 74 women undergoing OTT (n = 51 with menopausal levels of FSH; n = 23 with premenopausal levels) were followed by measurements of FSH, LH, AMH, and oestradiol. Concentrations of FSH and LH returned to premenopausal levels after 20 weeks on average, with a concomitant increase in oestradiol. Despite resumption of ovarian activity, AMH concentrations were in most instances below the detection limit in the menopausal group, suggesting a low ovarian reserve. Despite a higher age in the premenopausal group, they more often experienced an AMH increase than the menopausal group, suggesting that conditions in the premenopausal ovary better sustain follicle survival, perhaps due to the higher concentrations of oestradiol. Collectively, this study highlights the need for improving follicle survival after OTT. Age and the amount of tissue transplanted are important factors that influence the ability to regain ovarian activity and levels of FSH may need to be downregulated and oestradiol increased prior to OTT.

Disparities in Female Pediatric, Adolescent and Young Adult Oncofertility: A Needs Assessment

Advancements in cancer screening and implementation of targeted treatments have significantly improved survival rates to 85% for pediatric and AYA survivors. Greater than 75% of survivors will live to experience the long-term adverse outcomes of cancer therapies, termed late effects (LE), that disrupt quality of life (QoL). Infertility and poor reproductive outcomes are significant disruptors of QoL in survivorship, affecting 12-88% of survivors who receive at-risk therapies. To mitigate risk, fertility preservation (FP) counseling is recommended as standard of care prior to gonadotoxic therapy. However, disparities in FP counseling, implementation of FP interventions, and screening for gynecologic late effects in survivorship persist. Barriers to care include a lack of provider and patient knowledge of the safety and breadth of current FP options, misconceptions about the duration of time required to implement FP therapies, cost, and health care team bias. Developing strategies to address barriers and implement established guidelines are necessary to ensure equity and improve quality of care across populations.

Hormonal response in patients transplanted with cryopreserved ovarian tissue is independent of whether freezing was performed in childhood or adulthood

PURPOSE

This study evaluated the concentrations of hormones resulting from the transplantation of ovarian tissue (OTT) in relation to whether the tissue was frozen at a time close to puberty or above the age of 19 years.

METHODS

Six girls and adolescents (aged 9-14 years) who underwent ovarian tissue cryopreservation (OTC) were followed after transplantation in adulthood. After OTT, the women were followed via regular blood samples to evaluate the concentrations of FSH, LH, oestradiol and AMH. Twenty-three women undergoing OTT (aged 19-36 years at the time of OTC) were included as a reference group. All of the women had postmenopausal levels of gonadotropins at the time of transplantation.

RESULTS

The return of FSH and LH to normal premenopausal concentrations in adult women transplanted with ovarian tissue that was frozen at a time close to puberty was similar to the profiles in women from the reference group. Serum AMH levels were below the detection limit (via the Roche Elecsys assay) in many samples, but four out of six young girls showed measurable concentrations. Oestradiol similarly increased in the first 12 weeks following transplantation, after which it tended to be higher in women having frozen tissue in adulthood.

CONCLUSIONS

Ovarian tissue that was excised from girls at a time close to puberty, after which it was frozen and transplanted in adulthood, interacts with pituitary tissue in a similar manner to ovarian tissue that is frozen from adult women. Follicles located in the ovarian tissue from young girls are equally sensitive to gonadotropin stimulation as follicles from adult women when exposed to postmenopausal levels of gonadotropins. This result indicates that it is not the ovaries that require maturation to sustain full reproductive potential but rather proper FSH and LH stimulation. Moreover, these results support the continued use of OTC in young women.

Complete Purging of Ewing Sarcoma Metastases from Human Ovarian Cortex Tissue Fragments by Inhibiting the mTORC1 Signaling Pathway

Restoration of fertility by autologous transplantation of ovarian cortex tissue in former cancer patients may lead to the reintroduction of malignancy via the graft. Pharmacological ex vivo purging of ovarian cortex fragments prior to autotransplantation may reduce the risk of reseeding the cancer. In this study we have investigated the capacity of Everolimus (EVE), an inhibitor of the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway, to eradicate Ewing’s sarcoma (ES) from ovarian tissue by a short-term ex vivo treatment. Exposure of experimentally induced ES tumor foci in ovarian tissue to EVE for 24 h completely eliminated the malignant cells without detrimental effects on follicle morphology, survival or early folliculogenesis. This indicates that effective purging of ovarian cortex tissue from contaminating ES tumor foci is possible by short-term exposure to EVE.

Longitudinal study of AMH variations in 122 Adolescents and Young Adults (AYA) and non-AYA lymphoma patients to evaluate the chemo-induced ovarian toxicity to further personalise fertility preservation counselling

STUDY QUESTION

What is the influence of age and chemotherapy regimen on the longitudinal blood anti-Müllerian hormone (AMH) variations in a large series of adolescents and young adult (AYA) (15-24 years old) and non-AYA (25-35 years old) lymphoma patients?

SUMMARY ANSWER

In case of alkylating regimen treatment, there was a deep and sustained follicular depletion in AYA as well as non-AYA patients; however in both groups, the ovarian toxicity was extremely low in cases of non-alkylating treatments.

WHAT IS KNOWN ALREADY

AMH is now well-recognised to be a real-time indicator of ovarian follicular depletion and recovery in women treated by chemotherapy. Its longitudinal variations may discriminate between highly and minimally toxic protocols regarding ovarian function. It has been shown, in different cancer types, that age, type of chemotherapy regimen and pre-treatment AMH levels are the main predictors of ovarian recovery. Large studies on longitudinal AMH variations under chemotherapy in lymphoma patients are few but can provide the opportunity to assess the degree of follicle loss at a young age.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study was conducted in the Fertility Observatory of the Lille University Hospital. Data were collected between 2007 and 2016. Non-Hodgkin or Hodgkin lymphoma patients (n = 122) between 15 and 35 years old were prospectively recruited before commencing chemotherapy. Patients were treated either by a non-alkylating protocol (ABVD group; n = 67) or by an alkylating regimen (alkylating group; n = 55).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Serial AMH measurements were performed at baseline (AMH0), 15 days after the start of chemotherapy (AMH1), 15 days before the last chemotherapy cycle (AMH2), and at time 3, 6, 9, 12, 18 and 24 months from the end of chemotherapy. The whole study population was divided into two groups according to age: AYA (15-24; n = 65) and non-AYA (25-35; n = 57). All patients received a once monthly GnRH agonist injection during the whole treatment period. A linear mixed model was used to account for the repeated measures of single patients.

MAIN RESULTS AND THE ROLE OF CHANCE

At baseline, non-AYA patients had higher BMI and lower AMH levels than AYA patients. All AYA and non-AYA patients having received ABVD protocols had regular cycles at 12 months of follow-up. In case of alkylating regimens, amenorrhoea was more frequent in non-AYA patients than in AYA patients at 12 months (37% vs 4%, P = 0.011) and at 24 months (24% vs 4%, P = 0.045). We distinguished a similar depletion phase from AMH0 to AMH2 between ABVD and alkylating groups but significantly different recovery phases from AMH2 to AMH + 24 months. AMH recovery was fast and complete in case of ABVD protocols whatever the age: AMH reached pre-treatment values as soon as the 6th month of follow-up in the AYA group (mean (95% CI) in log AMH M0 vs M6: 3.07 (2.86 to 3.27) vs 3.05 (2.78 to 3.31), P = 1.00) and in the non-AYA group (mean (95% CI) in log AMH M0 vs M6: 2.73 (2.40 to 3.05) vs 2.47 (2.21 to 2.74), P = 1.00). In contrast, no patients from the alkylating group returned to pre-treatment AMH values whatever the age of patients (AYA or non-AYA). Moreover, none of the AMH values post-chemotherapy in the non-AYA group were significantly different from AMH2. Conversely in the AYA group, AMH levels from 6 months (mean (95% CI) in log AMH: 1.79 (1.47 to 2.11), P < 0.001) to 24 months (mean (95% CI) in log AMH: 2.16 (1.80 to 2.52), P ≤ 0.001) were significantly higher than AMH2 (mean (95% CI) in log AMH: 1.13 (0.89 to 1.38)). Considering the whole study population (AYA and non-AYA), pre-treatment AMH levels influenced the pattern of the AMH variation both in alkylating and ABVD protocols (interaction P-value = 0.005 and 0.043, respectively). Likewise, age was significantly associated with the pattern of the recovery phase but only in the alkylating group (interaction P-value =0.001). BMI had no influence on the AMH recovery phase whatever the protocol (interaction P-value = 0.98 in alkylating group, 0.72 in ABVD group).

LIMITATIONS, REASONS FOR CAUTION

There was a large disparity in subtypes of protocols in the alkylating group. The average duration of chemotherapy for patients treated with alkylating protocols was longer than that for patients treated with ABVD.

WIDER IMPLICATIONS OF THE FINDINGS

These results make it possible to develop strategies for fertility preservation according to age and type of protocol in a large series of young lymphoma patients. In addition, it was confirmed that young age does not protect against ovarian damage caused by alkylating agents.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by Agence Régionale de Santé Hauts de France and Agence Onco Hauts-de-France who provided finances for AMH dosages (n° DOS/SDES/AR/FIR/2019/282). There are no competing interests.

TRIAL REGISTRATION NUMBER

DC-2008-642 and CNIL DEC2015-112.

Effects of Er:YAG laser treatment on re-vascularization and follicle survival in frozen/thawed human ovarian cortex transplanted to immunodeficient mice

PURPOSE

The huge loss of ovarian follicles after transplantation of frozen/thawed ovarian tissue is considered a major drawback on the efficacy of the procedure. Here we investigate whether Er:YAG laser treatment prior to xenotransplantation can improve re-vascularization and subsequently follicle survival in human ovarian tissue.

METHODS

A total of 99 frozen/thawed human ovarian cortex pieces were included of which 72 pieces from 12 woman were transplanted to immunodeficient mice. Tissues from each woman were included in both an 8-day and an 8-week duration study and treated with either full-beam laser (L1) or fractionated laser (L2), or served as untreated controls. Vascularization of the ovarian xenografts were evaluated after 8 days by qPCR and murine Cd31 immunohistochemical analysis. Follicle densities were evaluated histologically 8 weeks after xenografting.

RESULTS

Gene expression of Vegf/VEGF was upregulated after L1 treatment (p=0.002, p=0.07, respectively), whereas Angpt1, Angpt2, Tnf-α, and Il1-β were significantly downregulated. No change in gene expression was found in Cd31/CD31, ANGPT1, ANGPT2, ANGTPL4, XBP1, or LRG1 after any of the laser treatments. The fraction of Cd31 positive cells were significantly reduced after L1 and L2 treatment (p<0.0001; p=0.0003, respectively), compared to controls. An overall negative effect of laser treatment was detected on follicle density (p=0.03).

CONCLUSIONS

Er:YAG laser treatment did not improve re-vascularization or follicle survival in human ovarian xenografts after 8 days and 8 weeks grafting, respectively. However, further studies are needed to fully explore the potential angiogenic effects of controlled tissue damage using different intensities or lasers.

Fertility preservation and management of pregnancy in melanoma patients requiring systemic therapy

Melanoma is one of the most common cancers in adolescents and adults at fertile age, especially in women. With novel and more effective systemic therapies that began to profoundly change the dismal outcome of melanoma by prolonging overall survival, the wish for fertility preservation or even parenthood has to be considered for a growing portion of melanoma patients-from the patients' as well as from the physicians' perspective. The dual blockade of the mitogen-activated protein kinase pathway by B-Raf proto-oncogene serine/threonine kinase and mitogen-activated protein kinase inhibitors and the immune checkpoint inhibition by anti-programmed cell death protein 1 and anti-cytotoxic T-lymphocyte-associated protein-4 monoclonal antibodies constitute the current standard systemic approaches to combat locally advanced or metastatic melanoma. Here, the preclinical data and clinical evidence of these systemic therapies are reviewed in terms of their potential gonadotoxicity, teratogenicity, embryotoxicity and fetotoxicity. Recommendations for routine fertility and contraception counseling of melanoma patients at fertile age are provided in line with interdisciplinary recommendations for the diagnostic work-up of these patients and for fertility-protective measures. Differentiated recommendations for the systemic therapy in both the adjuvant and the advanced, metastatic treatment situation are given. In addition, the challenges of pregnancy during systemic melanoma therapy are discussed.

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.

Experience with transplantation of human cryopreserved ovarian tissue to a sub-peritoneal abdominal site

STUDY QUESTION

Is a sub-peritoneal abdominal site a suitable site for cryopreserved ovarian tissue transplantation?

SUMMARY ANSWER

Live births have resulted from oocytes aspirated from follicles within cryopreserved ovarian tissue transplanted in a sub-peritoneal abdominal site with similar outcomes observed in terms of number of mature oocytes recovered and embryo development from tissue transplanted to sub-peritoneal abdominal, ovarian, and pelvic sites in our clinic.

WHAT IS KNOWN ALREADY

Over 130 live births have been reported from cryopreservation of ovarian tissue and subsequent transplantation. In the majority of these, tissue was transplanted onto the remaining ovary. Although grafting to a non-ovarian, non-pelvic, sub-peritoneal abdominal site has resulted in births, it has been suggested that compromised outcomes may be expected from a non-pelvic site.

STUDY DESIGN, SIZE, DURATION

The aim of the study was to assess the outcome from cryopreserved ovarian tissue transplanted to a site out of the pelvic area; a sub-peritoneal abdominal site. These outcomes were compared to transplantation to the ovary and peritoneal pelvic area in a cohort of 17 fertility preservation women where the individual sites of follicle aspiration were known and subsequent outcomes tracked. Ovarian tissue was slow frozen using the cryoprotectants propanediol and sucrose (n = 16 women) or using dimethyl sulfoxide and sucrose (n = 1 woman). Tissue was kept at 4°C overnight prior to freezing for 1 case. Tissue was thawed appropriately and prepared on 6.0 vicryl sutures for transplantation. Tissue was placed laparoscopically into a sub-peritoneal abdominal site, a pelvic side wall peritoneal pocket and the ovary.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Following resumption of cycling, gonadotrophin stimulation commenced with FSH, LH and antagonist and a trigger was given when one follicle was >13 mm in diameter. Abdominal follicles were aspirated under ultrasound guidance trans-abdominally; ovarian and pelvic follicles were aspirated trans-vaginally. Due to an inability to differentiate pelvic from ovarian follicles at the time of ultrasound-guided oocyte retrieval, both were classified as ovarian on the side where both were present. However, on the side, where no ovary was present, outcomes from pelvic follicles were reported.

MAIN RESULTS AND THE ROLE OF CHANCE

Average time lapse between ovarian tissue harvest and graft was 6 years. Resumption of cycling occurred on average 4.2 months post first graft, regardless of graft site. Mean follicle diameter on the day of oocyte aspiration was 14 mm for all sites. Aspiration failed to retrieve an oocyte in 30% (36/120) of abdominal follicles which was similar to the other sites; ovarian 24% (21/87), pelvic 32% (31/97). A similar proportion of retrieved oocytes was mature from all sites (67% (50/75) abdominal, 68% (42/62) ovarian, 59% (34/58) pelvic). The proportion of embryos which developed on Day 2 from those fertilized was also similar in all groups (90% (34/38) abdominal, 76% (22/29) ovarian, 96% (22/23) pelvic). To our knowledge, this is the first report of outcomes from cryopreserved ovarian tissue transplanted to a sub-peritoneal abdominal site and the subsequent comparison to outcomes from the ovary and a sub-peritoneal pelvic graft, within the same cohort of patients, where tissue was slow frozen predominantly with the cryoprotectant propanediol and sucrose.

LIMITATIONS, REASONS FOR CAUTION

The study reports outcomes from a small number of women following ovarian tissue transplantation. Follicle density is an estimate only and the amount of tissue grafted varied between patients.

WIDER IMPLICATIONS OF THE FINDINGS

The demonstration of successful outcomes from cryopreserved ovarian tissue grafted to a sub-peritoneal abdominal site has significant implications for the management of women in which grafting to pelvic sites is contraindicated although it appears to be important to trigger follicle maturation at a lower than normal follicular diameter. The relative ease of oocyte retrieval at the sub-peritoneal abdominal site also has positive implications for the introduction of this approach into clinical practice.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was used. All authors have no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Ovarian tissue damage after grafting: systematic review of strategies to improve follicle outcomes

Frozen-thawed human ovarian tissue endures large-scale follicle loss in the early post-grafting period, characterized by hypoxia lasting around 7 days. Tissue revascularization occurs progressively through new vessel invasion from the host and neoangiogenesis from the graft. Such reoxygenation kinetics lead to further potential damage caused by oxidative stress. The aim of the present manuscript is to provide a systematic review of proangiogenic growth factors, hormones and various antioxidants administered in the event of ovarian tissue transplantation to protect the follicle pool from depletion by boosting revascularization or decreasing oxidative stress. Although almost all investigated studies revealed an advantage in terms of revascularization and reduction in oxidative stress, far fewer demonstrated a positive impact on follicle survival. As the cascade of events driven by ischaemia after transplantation is a complex process involving numerous players, it appears that acting on specific molecular mechanisms, such as concentrations of proangiogenic growth factors, is not enough to significantly mitigate tissue damage. Strategies exploiting the activated tissue response to ischaemia for tissue healing and remodelling purposes, such as the use of antiapoptotic drugs and adult stem cells, are also discussed in the present review, since they yielded promising results in terms of follicle pool protection.

Fertility preservation in men and women: Where are we in 2021? Are we rising to the challenge?

Demand for fertility preservation in women for oncologic, nononcologic, and personal reasons has increased dramatically. Meeting that demand is a major challenge, and we are rising to the challenge. Mature oocyte cryopreservation after ovarian stimulation and ovarian tissue cryopreservation are both methods endorsed by the American Society for Reproductive Medicine (formerly The American Fertility Society), and numerous papers confirmed their efficacy. In girls and women with leukemia or cancers who are at a high risk of ovarian metastasis and who may not be eligible for ovarian tissue transplantation, restoration of fertility can only be achieved by in vitro methods. Male fertility preservation has also become a pressing issue and is extensively reviewed in the present journal issue.