Live birth after ovarian tissue autotransplantation following overnight transportation before cryopreservation

Perinatal outcomes of pregnancies following autologous cryopreserved ovarian tissue transplantation: a systematic review with pooled analysis

OBJECTIVE

This study aimed to synthesize the existing evidence on perinatal outcomes after autologous cryopreserved ovarian tissue transplantation, concurrently identifying key factors influencing these outcomes.

DATA SOURCES

A comprehensive search was performed on MEDLINE, Embase, and Cochrane Library databases to identify relevant studies on the effect of autologous cryopreserved ovarian tissue transplantation on perinatal outcomes from inception to October 22, 2023. Where there was missing information, the authors were contacted for updated data.

STUDY ELIGIBILITY CRITERIA

Observational studies, such as cohort studies, case series, and case reports that reported a live birth after autologous cryopreserved ovarian tissue transplantation, were considered eligible. Studies lacking data on women's demographic characteristics, autologous cryopreserved ovarian tissue transplantation procedure details, or perinatal outcomes were excluded. In addition, cases involving fresh or nonautologous transplantations and those addressing primary ovarian insufficiency were excluded.

METHODS

Two reviewers (M.E. and E.U.) independently performed the study selection, data extraction, and risk of bias assessment, and the results were then reviewed together. The PRISMA guidelines were followed, and the protocol was registered on PROSPERO (CRD42023469296).

RESULTS

This review included 58 studies composed of 122 women with 162 deliveries (154 singletons and 8 twins) after autologous cryopreserved ovarian tissue transplantation, resulting in 170 newborns. Of note, 83.6% of the women had a malignant disease. Moreover, most of these women (51.0%) were exposed to some form of chemotherapy before ovarian tissue cryopreservation. Of the 162 childbirths, 108 (66.7%) were conceived naturally, and 54 (33.3%) were conceived through assisted reproductive techniques. The birthweight of 88.5% of newborns was appropriate for gestational age, whereas 8.3% and 3.1% were small for gestational age and large for gestational age, respectively. The preterm birth rate was 9.4%, with the remaining being term deliveries. Hypertensive disorders of pregnancy were noted in 18.9% of women, including pregnancy-induced hypertension in 7.6%, preeclampsia in 9.4%, and hemolysis, elevated liver enzymes, and low platelet count in 1.9%. The incidences of gestational diabetes mellitus and preterm premature rupture of membranes were 3.8% for each condition. Neonatal anomalies were reported in 3 transplant recipients with 4 newborns: arthrogryposis, congenital cataract, and diaphragmatic hernia in a twin. Finally, among the recipients' characteristics, not receiving chemotherapy before ovarian tissue cryopreservation (odds ratio, 0.23; 95% confidence interval, 0.07-0.72; P=.012) and natural conception (odds ratio, 0.29; 95% confidence interval, 0.09-0.92; P=.035) were associated with a lower perinatal complication rate.

CONCLUSION

On the basis of low certainty evidence from observational studies, perinatal complication rates did not increase after autologous cryopreserved ovarian tissue transplantation compared with the general pregnant population, except for preeclampsia. This could be due to chemotherapy exposure, underlying medical conditions, and the common use of assisted reproductive techniques. Further larger studies are needed to explore the causes of increased preeclampsia incidence in autologous cryopreserved ovarian tissue transplantation pregnancies.

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.

Does it make sense to refreeze ovarian tissue after unexpected occurrence of endometriosis when transplanting the tissue?

Background

Ovarian insufficiency is a major concern for long-term cancer survivors. Ovarian tissue cryopreservation for fertility preservation is an emerging technique that has proven successful over the past decade through transplantation of frozen-thawed ovarian tissue. Compared to other established techniques, such as oocyte freezing, ovarian tissue cryopreservation preserves actual organ function and thus the production of sex hormones. Endometriosis in perimenopausal women is rare, however it can be surprising diagnosis in the planned transplantation of cryopreserved ovarian tissue and the already thawed tissue may not be transplanted, so that it has to be refrozen.

Results

Ovarian function returned in the patient two months after transplantation, as shown by estrogen production. Ten months after the ovarian tissue transplantation mild stimulation with FSH was initiated in accordance with a low-dose protocol. When ultrasonography revealed a follicle 17 mm in size in the ovarian graft, hCG was added and after follicular puncture one oocyte was obtained. The oocyte could be fertilized by IVF and transferred to the uterus. On day 14 after embryo-transfer, a positive hCG-Level was detected and after an uncomplicated pregnancy a healthy child was delivered.

Conclusions

We report the first pregnancy and live birth achieved using transplantation of thawed and refrozen ovarian tissue in a woman treated by chemotherapy and subsequent endometriosis surgery. Refreezing of cryopreserved ovarian tissue is not a hindrance to successful transplantation of ovarian tissue. Against the background of increasing numbers of candidates for transplantation of ovarian tissue is expected that the combination chemotherapy followed by endometriosis will increase.

Shortening the duration between ovarian removal and cryopreservation helps preserve fertility and maintain ovarian reserve after transplantation in mice

OBJECTIVE

To evaluate the effect of storage of ovaries before cryopreservation on long-term fertility and ovarian reserve after transplantation in mice.

DESIGN

Experimental study.

SETTING

University hospital.

ANIMAL(S)

C57BL/6J and C57BL/6J-Tg (CAG-GFP) female mice.

INTERVENTION(S)

Storage and cryopreservation of mouse ovaries. Long-term fertility analysis of mice transplanted with thawed ovaries.

MAIN OUTCOME MEASURE(S)

Estrous cycles, number of live births, ovarian weight, and follicular counts of ovarian grafts.

RESULT(S)

At the first mating 3 months after ovarian transplantation, the mean number of live births was 2.6 ± 0.6 in the control group (no storage); in the storage groups, the mean number of live births was 2.9 ± 0.7 after 4 hours, 1.3 ± 0.5 after 8 hours, 0.2 ± 0.2 after 12 hours, and 0.8 ± 0.5 after 24 hours of storage; the difference from the control group was significant in the 12-hour storage group. At the second mating 6 months after ovarian transplantation, the mean number of live births was 1.8 ± 0.6 in the control group and 2.4 ± 0.6 and 0.3 ± 0.2 in the 4- and 8-hour storage groups, respectively; no live births occurred in the 12- and 24-hour storage groups. Seven months after ovarian transplantation, the numbers of primordial, primary, early secondary, and late secondary follicles were significantly lower in the 8-, 12-, and 24-hour storage groups than in the control group.

CONCLUSION(S)

In mice, shortening the storage time of ovaries before cryopreservation preserved fertility and ovarian reserve after transplantation, indicating that human ovaries might be cryopreserved immediately after harvesting or transported as quickly as possible to a cryopreservation facility to allow young patients with cancer to preserve long-term fertility and ovarian reserve.

Preoperative Cryopreservation Promotes Digital Survival after Digit Replantation

Cryopreservation has been applied in the replantation of limbs with a minimal amount of muscle tissue replanted. And small composite tissues have also been reported to be successfully replanted by preoperative cryopreservation. In this study, we aimed to study the effect of preoperative cryopreservation on digital survival after digit replantation. Accordingly, we collected and compared the demographic and clinicopathological characteristics of patients with digit injury of patients, and we observed no significant difference between the NT and CP patients of digital injury. We also investigated the records of successful digit replantation and other parameters which influenced the odds of digital survival of all recruited patients. Accordingly, we found that the number of survived digits was remarkably increased in patients in the CP group compared with that in patients in the NT group. And the number of patients requiring blood transfusion and the mean length of hospital stay were notably decreased in the CP group. And compared with other patient characteristics, the mechanism of injury (blade, crush, or avulsion) showed a remarkable difference between the two groups of digital failure. Moreover, we analyzed the correlations between patient characteristics and the odds of digit survival and found that compared with other basic characteristics of patients and their injury, the preservation temperature, especially cryopreservation, could significantly promote digital survival after replantation.

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 Systematic Review of Ovarian Tissue Transplantation Outcomes by Ovarian Tissue Processing Size for Cryopreservation

Ovarian tissue cryopreservation (OTC) is the only pre-treatment option currently available to preserve fertility for prepubescent girls and patients who cannot undergo ovarian stimulation. Currently, there is no standardized method of processing ovarian tissue for cryopreservation, despite evidence that fragmentation of ovaries may trigger primordial follicle activation. Because fragmentation may influence ovarian transplant function, the purpose of this systematic review was (1) to identify the processing sizes and dimensions of ovarian tissue within sites around the world, and (2) to examine the reported outcomes of ovarian tissue transplantation including, reported duration of hormone restoration, pregnancy, and live birth. A total of 2,252 abstracts were screened against the inclusion criteria. In this systematic review, 103 studies were included for analysis of tissue processing size and 21 studies were included for analysis of ovarian transplantation outcomes. Only studies where ovarian tissue was cryopreserved (via slow freezing or vitrification) and transplanted orthotopically were included in the review. The size of cryopreserved ovarian tissue was categorized based on dimensions into strips, squares, and fragments. Of the 103 studies, 58 fertility preservation sites were identified that processed ovarian tissue into strips (62%), squares (25.8%), or fragments (31%). Ovarian tissue transplantation was performed in 92 participants that had ovarian tissue cryopreserved into strips (n = 51), squares (n = 37), and fragments (n = 4). All participants had ovarian tissue cryopreserved by slow freezing. The pregnancy rate was 81.3%, 45.5%, 66.7% in the strips, squares, fragment groups, respectively. The live birth rate was 56.3%, 18.2%, 66.7% in the strips, squares, fragment groups, respectively. The mean time from ovarian tissue transplantation to ovarian hormone restoration was 3.88 months, 3.56 months, and 3 months in the strips, squares, and fragments groups, respectively. There was no significant difference between the time of ovarian function' restoration and the size of ovarian tissue. Transplantation of ovarian tissue, regardless of its processing dimensions, restores ovarian hormone activity in the participants that were reported in the literature. More detailed information about the tissue processing size and outcomes post-transplant are required to identify a preferred or more successful processing method.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk], identifier [CRD42020189120].

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

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

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

STUDY OBJECTIVES

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

DESIGN

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

SETTING

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

PARTICIPANTS

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

INTERVENTIONS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

NCT02872532, NCT02646384.

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

RESEARCH QUESTION

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

DESIGN

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

RESULTS

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

CONCLUSION

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

Fertility preservation in endocrine responsive breast cancer: data and prejudices

Even if current guidelines suggest an early referral of young breast cancer (BC) patients to fertility preservation counselling, physicians still lack knowledge about the different available strategies. Hormonal stimulation to harvest mature oocytes is considered unsafe by many oncologists and experts in reproductive medicine, particularly in the setting of oestrogen receptor-positive BC. The aim of this mini-review is to provide an overview on the available data about this topic in order to clarify potential misunderstandings and to highlight the new trends in the oncofertility field with their pros and limitations.

Cryopreservation and Thawing of Human Ovarian Cortex Tissue Slices

Cryopreserved ovarian cortex tissue can be used to improve or restore female fertility. It can be used for cancer patients to restore fertility after chemotherapy treatment or for social reasons for women who want to postpone their pregnancy wish. In order to preserve ovarian tissue viability in these cases, the tissue needs to be stored by cryopreservation. In this chapter we describe the entire process chain needed to prepare, transport, and cryopreserve human ovarian cortex tissues as well as to subsequently thaw and implant it.

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

BACKGROUND/AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Ovarian tissue cryopreservation and novel bioengineering approaches for fertility preservation

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Hormonal Stimulation of Human Ovarian Xenografts in Mice: Studying Folliculogenesis, Activation, and Oocyte Maturation

Ovarian tissue cryopreservation and banking provides a fertility preservation option for patients who cannot undergo oocyte retrieval; it is quickly becoming a critical component of assisted reproductive technology programs across the world. While the transplantation of cryopreserved ovarian tissue has resulted in over 130 live births, the field has ample room for technological improvements. Specifically, the functional timeline of grafted tissue and each patient's probability of achieving pregnancy is largely unpredictable due to patient-to-patient variability in ovarian reserve, lack of a reliable method for quantifying follicle numbers within tissue fragments, potential risk of reintroduction of cancer cells harbored in ovarian tissues, and an inability to control follicle activation rates. This review focuses on one of the most common physiological techniques used to study human ovarian tissue transplantation, xenotransplantation of human ovarian tissue to mice and endeavors to inform future studies by discussing the elements of the xenotransplantation model, challenges unique to the use of human ovarian tissue, and novel tissue engineering techniques currently under investigation.

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

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

Hypothermic machine perfusion after static cold storage improves ovarian function in rat ovarian tissue transplantation

OBJECTIVE

This study was performed to investigate the effect of hypothermic machine perfusion (HMP) after cold storage (CS) on ovarian transplantation.

METHODS

Rats aged 8-10 weeks were used as the donors and recipients for allotransplantation. Eighteen donor rats were divided into three groups: the fresh control (n = 6), cold storage (CS; n = 6), and hypothermic machine perfusion (HMP; n = 6) groups. The preservation solution contained Dulbecco's modified Eagle's medium/Ham's F-12 (1:1, v/v), 10% fetal bovine serum, 10 μg/ml insulin, 10 μg/ml transferrin, and 50 mIU/ml follicle-stimulating hormone (FSH). The donor ovaries in the CS and HMP groups were excised and then respectively subjected to 4 h of CS and 2 h of CS combined with 2 h of HMP at 4 °C, and then transplanted beneath the recipient's left renal capsule. At 7 days after transplantation, the ovaries were removed and blood samples were obtained for histological analysis, immunohistochemistry for CD31 and Ki67, and serum anti-Mullerian hormone (AMH) level estimation.

RESULTS

The HMP group showed significant increases in serum AMH and CD31-positive areas when compared to these values in the CS group (P < 0.05). However, no differences were noted in the total number of follicles or the Ki67-positive areas among the three groups.

CONCLUSION

Hypothermic machine perfusion after static cold storage is more effective than static CS alone for the short-term preservation of whole ovaries during transport. Whole ovary transplantation with vascular pedicle is our future research direction. Graphical Abstract The black rectangle in the figure shows the place where ligation and disconnection are required, the black dotted line shows the place where vascular forceps are used to clamp, and the black circle shows the place where the cannula is inserted This diagram was made for reviewers to understand more intuitively how my hypothermia mechanical perfusion model was built. Organs obtained in this way can be used for subsequent perfusion and whole ovarian transplantation.

Ovarian stimulation is a safe and effective fertility preservation option in the adolescent and young adult population

PURPOSE

The aim of this study is to describe the multidisciplinary approach and controlled ovarian hyperstimulation (COH) outcomes in adolescent and young adult (AYA) patients (ages 13-21) who underwent oocyte cryopreservation for fertility preservation (FP).

METHODS

Multi-site retrospective cohort was performed from 2007 to 2018 at Northwestern University and Michigan University. Data were analyzed by chi-square test, t-test, and logistic regression.

RESULTS

Forty-one patients began COH of which 38 patients successfully underwent oocyte retrieval, with mature oocytes obtained and cryopreserved without any adverse outcomes. To treat this group of patients, we use a multidisciplinary approach with a patient navigator. When dividing patients by ages 13-17 vs. 18-21, the median doses of FSH used were 2325 and 2038 IU, the median number of mature oocytes retrieved were 10 and 10, and median number frozen oocytes were 11 and 13, respectively. Median days of stimulation were 10 for both groups. There was no statistical difference in BMI, AMH, peak E₂, FSH dosage, days stimulated, total oocytes retrieved, mature oocytes retrieved, and oocytes frozen between the two groups. Three patients were canceled for poor response.

CONCLUSION

COH with oocyte cryopreservation is a feasible FP option for AYAs who may not have other alternatives when appropriate precautions are taken, such as proper counseling and having a support team. These promising outcomes correspond to similar findings of recent small case series, providing hope for these patients to have genetically related offspring in the future.

Ovarian function and reproductive outcome after ovarian tissue transplantation: a systematic review

The aim of this systematic review study is to summarize the current knowledge of ovarian tissue transplantation and provide insight on ovarian function, fertility and reproductive outcome following ovarian tissue transplantation. Relevant studies were identified by searching through PubMed, Cochrane Library, Embase, ProQuest, and Scopus databases until August 2018. Ovarian function by examination of the hormonal level was evaluated, together with follicular growth, the return of menstrual cycle and assessment of reproductive consequences: pregnancy, miscarriage rates and live birth after transplantation. Studies including female patients aged between 22 and 49 years that were subjected to ovarian tissue transplantation were considered. A total of 1185 studies were identified in the primary search. Titles and abstracts were screened for assessment of the inclusion criteria. Finally, twenty-five articles met the criteria and were included in this study. In general, 70% of patients that underwent ovarian tissue transplantation had ovarian and endocrine function restoration as well as follicular growth. Pregnancy was reported with 52% of the patients. The available evidence suggests that ovarian tissue transplantation is a useful and an applied approach to restore hormonal function, endocrine balance and eventually fertility outcomes in patients that are predisposed to lose their fertility, diagnosed with premature ovarian failure (POF), as well as women undergoing cancer treatments. Identification of the techniques with the lowest invasions for follicular and oocyte development after ovarian tissue transplantation aiming to reduce probable adverse effects after treatment is indispensable.

Reproductive outcomes following a stem cell transplant for a haematological malignancy in female cancer survivors: a systematic review and meta-analysis

PURPOSE

The use of high-dose chemotherapy and radiotherapy combined with haematopoietic stem cell transplantation (HSCT) may negatively affect a woman's reproductive potential. Reproductive outcomes such as infertility are a major concern for women who undergo treatment for a haematological cancer diagnosis.

OBJECTIVE

This systematic review and meta-analysis explores reproductive outcomes following a haematological cancer requiring HSCT.

METHODS

Electronic databases were searched to identify studies that reported on reproductive outcomes after treatment for a haematological cancer diagnosis. Studies were included that reported on pregnancy and reproductive outcomes following HSCT for a haematological malignancy.

RESULTS

The meta-analysis included 14 studies, collectively involving 744 female patients. The subgroup analysis showed an overall pooled estimated pregnancy rate, for autologous or allogeneic HSCT recipients, of 22.7% (n = 438). There were 25% (n = 240) of women who became pregnant after autologous HSCT compared with 22% (n = 198) who subsequently became pregnant following allogeneic HSCT.

CONCLUSIONS

This meta-analysis reflects low pregnancy rates for cancer survivors desiring a family. However, live births are improving over time with new technology and novel therapies. Hence, female cancer patients should be offered timely discussions, counselling and education around fertility preservation options prior to starting treatment with gonadotoxic therapy.

Ovarian Tissue Transplantation: Experience From Germany and Worldwide Efficacy

Extraction of ovarian tissue prior to oncologic therapy and subsequent transplantation is being performed increasingly often to preserve fertility in women. The procedure can be performed at any time of the cycle and, therefore, generally does not lead to any delay in oncological therapy. Success rates with transplantation of cryopreserved ovarian tissue have reached promising levels. More than 130 live births have been reported worldwide with the aid of cryopreserved ovarian tissue and the estimated birth rate is currently approximately 30%. In Germany, Austria, and Switzerland, the FertiPROTEKT consortium has successfully achieved 21 pregnancies and 17 deliveries generated after 95 ovarian tissue transplantations by 2015, one of the largest case series worldwide confirming that ovarian tissue cryopreservation and transplantation are successful. Approximately, more than 400 ovarian tissue cryopreservation procedures are performed each year in the FertiPROTEKT consortium, and the request and operations for ovarian tissue transplantation have increased in recent years. Therefore, recommendations for managing transplantation of ovarian tissue to German-speaking reproductive medicine centers were developed. In this overview, these recommendations and our experience in ovarian tissue transplantation are presented and discussed with international procedures.

What will the future hold for artificial organs in the service of assisted reproduction: prospects and considerations

Assisted reproduction provides a wide spectrum of treatments and strategies addressing infertility. However, distinct groups of infertile patients with unexplained infertility, congenital disorders, and other complex cases pose a challenge in in vitro fertilization (IVF) practices. This special cohort of patients is associated with futile attempts, IVF overuse, and dead ends in management. Cutting edge research on animal models introduced this concept, along with the development of artificial organs with the aim to mimic the respective physiological functions in reproduction. Extrapolation on clinical application leads to the future use of infertility management in humans. To date, the successful clinical application of artificial reproductive organs in humans is not feasible because further animal model studies are required prior to clinical trials. The application of these artificial organs could provide a solution to infertility cases with no other options. This manuscript presents an overview on the current status, future prospects, and considerations on the potential clinical application of artificial ovary, uterus, and gametes in humans. This paper presents how the IVF practice landscape may be shaped and challenged in the future, along with the subsequent concerns in assisted reproductive treatments.

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

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

Oocyte collection and in vitro maturation after train transportation of human follicular fluid aspirated from resected non-stimulated ovaries of patients with endometrial adenocarcinoma

PURPOSE

Immature human oocytes from resected ovaries can be used for research and fertility preservation, though it is unknown whether it is feasible to transport oocytes for these purposes. This study examined in vitro maturation (IVM) outcomes after the transportation of human follicular fluid (HFF) containing oocytes.

METHODS

Fourteen patients with endometrial adenocarcinoma were enrolled. Oocytes obtained from the resected ovaries of seven patients were transported with HFF by railway (transportation group). Samples of HFF from the other seven patients were not transported, and IVM was performed promptly (non-transportation group). The results of oocyte retrieval and IVM were compared.

RESULTS

The average ages in the transportation and non-transportation groups were 40.1 ± 2.0 and 39.6 ± 1.8 years, respectively, and the average numbers of collected oocytes were 8.1 ± 8.4 and 5.1 ± 5.1, respectively. There was a significant negative correlation between the number of collected oocytes and age. The proportions of oocytes that reached meiosis II (maturation rate) after IVM were 38.6% and 69.2% in the transportation and non-transportation groups, respectively (P = 0.013).

CONCLUSION

In this preliminary study, the usefulness of the transportation of HFF was limited. Further studies on maintaining oocyte normality during transportation are necessary for becoming the effective method for research and clinical use.

Electrospun patterned porous scaffolds for the support of ovarian follicles growth: a feasibility study

Recently, the interest of the scientific community is focused on the application of tissue engineering approach for the fertility restoration. In this paper innovative patterned electrospun fibrous scaffolds were fabricated and used as 3D system for porcine follicles culture. The obtained scaffolds demonstrated to be a suitable support which did not alter or interfere with the typical spherical follicles morphology. The fibrillar structure of the scaffolds mimics the morphology of the healthy native tissue. The use of porcine follicles implied many advantages respect to the use of mouse model. Relevant results showed that more than the scaffold pattern and struts dimension, the selection of proper biomaterials improve the follicles adhesion and development.

Cryostorage and retransplantation of ovarian tissue as an infertility treatment

While still considered an experimental procedure in most countries, ovarian tissue cryopreservation and transplantation has been increasingly applied worldwide to restore fertility in patients with malignant and non-malignant pathologies with risk of premature ovarian insufficiency. It has yielded more than 130 live births up to now and almost all transplanted patients recovered their ovarian function. This study summarizes ovarian tissue cryopreservation and transplantation indications, procedures, their efficacy and main results and proposes different strategies to improve this strategy. Although the main focus of this study is on ovarian tissue cryopreservation and transplantation as a strategy to restore fertility, we believe that it is also important to discuss other applications for this approach.

Overnight ovarian tissue transportation for centralized cryobanking: a feasible option

RESEARCH QUESTION

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Concept Paper on the Technique of Cryopreservation, Removal and Transplantation of Ovarian Tissue for Fertility Preservation

The cryopreservation of ovarian tissue with subsequent transplantation of the tissue represents an established method of fertility protection for female patients who have to undergo gonadotoxic therapy. The procedure can be performed at any point in the cycle and thus generally does not lead to any delay in oncological therapy. With the aid of this procedure, more than 130 births to date worldwide have been able to be recorded. The birth rate is currently approximately 30% and it can be assumed that this will increase through the further optimisation of the cryopreservation and surgical technique. The concept paper presented here is intended to provide guidance for managing cryopreservation and transplantation of ovarian tissue to German-speaking reproductive medicine centres.

Recent advances in oncofertility care worldwide and in Japan

BACKGROUND

Oncofertility is a crucial facet of cancer supportive care. The publication of guidelines for the cryopreservation of oocytes and ovarian tissue is becoming increasingly prevalent in Japan and an updated overview is necessary.

METHODS

In order to provide an updated overview of oncofertility care, original research and review articles were searched from the PubMed database and compared in order to present clinical care in Japan.

RESULTS

In Western countries, various methods for ovarian stimulation, such as the combined use of aromatase inhibitors and random-start protocols, have been reported. Although ovarian tissue cryopreservation, mainly performed via the slow-freezing method, also has yielded >100 live births, the optimal indications and procedures for the auto-transplantation of cryopreserved tissue have been under investigation. In Japan, however, vitrification is prevalent for ovarian tissue cryopreservation, although its efficacy has not yet been established. The quality of network systems for providing oncofertility care in Japan varies greatly, based on the region.

CONCLUSION

There remain many issues in the optimization of oncofertility care in Japan. Along with the regional oncofertility networks, the creation of "oncofertility navigators" from healthcare providers who are familiar with oncofertility, such as nurses, psychologists, and embryologists, could be useful for supplementing oncofertility care coordination, overcoming the issues in individual regions.

Cryopreservation and transplantation of ovarian tissue: results from one center in the USA

Purpose

To report the results of cryopreserved ovary tissue transplantation for leukemia and other cancers, in a single US center.

Methods

One hundred eight females between age 6 and (median age 24) 35 were referred for possible ovary tissue cryopreservation over a 20-year period, with either slow freeze or vitrification. Thus far 13 patients returned up to 18 years later to have their tissue transplanted back.

Results

All 13 patients had return of ovarian function 5 months post transplant with regular menstrual cycling. AMH rose to very high levels as the FSH declined to normal. Four months later, the AMH again declined to very low levels. Nonetheless, the grafts remained functional for up to 5 years or longer. Ten of the 13 (77%) became spontaneously pregnant at least once, resulting in 13 healthy babies. A total of 24 healthy babies have been born 11 from fresh transplanted ovarian tissue and 13 from cryopreserved transplanted ovarian tissue.

Conclusions

(1) Ovary tissue cryopreservation is a robust method for preserving a woman’s fertility. (2) Cortical tissue pressure may be a key regulator of primordial follicle arrest, recruitment, and ovarian longevity. (3) This is the only such series yet reported in the USA.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Age-related morphometrical peculiarities of Lithuanian women's primordial ovarian follicles

BACKGROUND

For the first time, thorough morphometrical measurements of primordial ovarian follicles were performed and their age-related changes were investigated in Lithuanian women of the reproductive age.

METHODS

Ovaries of dead women (n = 30) were divided into six age groups: 15-20 years old, 21-25 years old, 26-30 years old, 31-35 years old, 36-40 years old and 41-46 years old. Histological slides of left and right ovaries were stained using haematoxylin-eosin and periodic acid-Schiff (PAS) staining methods. The morphometrical measurements of 10 primordial ovarian follicles of the left and right ovary of each woman were made from microphotographs.

RESULTS

The diameter of primordial ovarian follicles increased in groups of women from 15 years old to 35 years old and decreased in the groups from 36 years old to 46 years old. The area of primordial ovarian follicles increased in the groups of women until 35 years old. It decreased in the groups of women older than 36 years. The follicular basement membrane thickened from 1.29 ± 0.11 μm to 1.43 ± 0.18 μm with increasing age of women. The diameter of primary oocytes enlarged until 35 years and then began to decrease. The area of primary oocytes increased in women until 35 years. It decreased in groups of women aged 36-40 and 41-46 years old. The diameter and the area of primary oocytes nuclei increased in women aged 15-30 years old; later, it began to decrease. The length of follicular cells varied from 8.56 ± 0.43 μm to 8.72 ± 0.27 μm (p > 0.05). The height of follicular cells varied from 2.59 ± 0.27 μm to 2.7 ± 0.21 μm (p > 0.05). The diameter, the area and the basement membrane thickness of primordial ovarian follicles and the diameter and the area of primary oocytes and their nuclei differed insignificantly in left and right ovaries in all age groups of women (p > 0.5). The length and height of follicular cells were similar in left and right ovaries of the same age group (p > 0.5).

CONCLUSIONS

The age decreasing of morphometrical parameters begins in primordial ovarian follicles and their primary oocytes in Lithuanian women older than 35 years. The thickness of the follicular basement membrane increased with increasing age of women. No significant differences were found in the morphometrical parameters in primordial follicles of left and right ovaries in the same age group of women.

Repetitive Maturation of Oocytes From Non-Stimulated Xenografted Ovarian Tissue From a Prepubertal Patient Indicating the Independence of Human Ovarian Tissue

Introduction

Modern anti-cancer strategies have distinctly increased survival rates; nevertheless, often accompanied by sterility. Currently, the only option for preserving fertility in prepubertal females is to cryopreserve ovarian tissue and re-transplant frozen-thawed tissue to restore fertility after treatment. Our aim was to report the occurrence of repetitive antral follicle formation and oocyte maturation in a prepubescent ovarian tissue xenograft without exogenous hormone stimulation.

Material and Methods

Frozen-thawed ovarian tissue from a 6-year-old patient suffering from nephroblastoma was xenotransplanted in oophorectomized severe combined immunodeficiency (SCID) mice to evaluate follicle development.

Ergebnisse

Repetitive follicle development to the antral stage occurred in the same xenograft of prepubertal ovarian tissue without exogenous hormone administration; 37 days after retrieving a maturing oocyte (this first retrieval has been previously published), another, completely mature oocyte was harvested from the xenograft. Subsequent histological evaluation of the grafted tissue showed primordial follicles, nearly all stages of developing follicles, as well as large atretic ones. Many clusters with dormant primordial follicles were also present.

Conclusion

Xenotransplanted prepubertal ovarian tissue has the potential for repetitive oocyte retrieval cycles without administering exogenous hormones. The results indicate that the human ovarian tissue might be able to synchronize the hypothalamus-hypophysis-axes of the mouse to the physiological human cycle; this should be investigated in future studies.

Fertility protection: complications of surgery and results of removal and transplantation of ovarian tissue

Fertility-preserving measures are becoming important for patients receiving oncological treatment. One method involves cryopreservation of ovarian tissue and transplanting it when treatment is completed. We report complications resulting from surgical and fertility medicine, and the results of procedures for the removal and transplantation of ovarian tissue carried out within the FertiProtekt network. A survey using a structured questionnaire was conducted among the FertiProtekt network centres between November 2015 and June 2016. The analysis included surgical techniques used to remove and transplant ovarian tissue, surgical complications and results. Laparoscopic removal and transplantation of ovarian tissue have a low risk of complications. Surgical complications occurred in three of the network's 1373 ovarian tissue removals (n = 1302) and transplantations (n = 71); two complications (0.2%) occurred during removal and one during transplantation. Menstruation resumed in 47 out of 58 women (81%) who underwent ovarian tissue transplantation. Hormonal activity occurred in 63.2% of transplantations with a follow-up of 6 months or over. Sixteen pregnancies occurred in 14 patients, with nine births. The risks and complications of removal and transplantation of ovarian tissue are similar to those of standard laparoscopy. These procedures are becoming standard for fertility protection in cancer patients.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

In vitro maturation of human immature oocytes for fertility preservation and research material

Aim

In recent years, the importance of fertility preservation (FP) has increased. In vitro maturation (IVM), an important technique in FP, has started to be used in the clinic, but controversies persist regarding this technique. Here, a survey of IVM for FP is provided.

Methods

Based on a literature review, the applications of FP, methods of FP, IVM of oocytes that had been collected in vivo and ex vivo, maturation of oocytes after IVM for FP, cryopreservation of oocytes for FP, explanation of the procedures to patients, and recent research on FP using IVM were investigated.

Results

Although IVM for FP remains controversial, the application of FP is expected to expand. Depending on the age and disease status of the patient, various methods of oocyte collection and ovarian stimulation, as well as various needle types and aspiration pressures, have been reported. The maturation rate of IVM in FP ranges widely and requires optimization in the future. In regard to cryopreservation for matured oocytes, the vitrification method is currently recommended.

Conclusion

Regarding FP for patients with cancer, the treatment of cancer is prioritized; thus, the time and use of medicines are often constrained. As several key points regarding IVM remain unclear, well‐designed and specific counseling for patients is necessary.

Complete protection against cryodamage of cryopreserved whole bovine and human ovaries using DMSO as a cryoprotectant

Purpose

This study aims to determine the optimal cryopreservation protocol for whole ovaries intended for preservation of fertility in women.

Methods

We investigated the optimal cryopreservation procedure for whole ovaries in a bovine model. The following parameters were investigated to determine their effect on ovarian tissue viability: type of cryoprotectant, administration route of the cryoprotectant (perfusion and/or submersion), and the maximum tolerable interval between death of the animal and start of the cryopreservation process. The resulting optimal cryopreservation procedure for bovine ovaries was subsequently tested on human ovaries. In vitro glucose uptake, histology, and immunohistochemistry were used to assess the integrity of the ovarian tissue.

Results

Starting the cryopreservation procedure (including perfusion with and submersion in DMSO) within 10–15 min after death of the animal proved critical, resulting in a 90–100% protection level against cryodamage. When cryopreserving human ovaries using the same protocol, over 95% protection against cryodamage was observed on all tissue levels. In addition, no apparent morphological damage to either the follicles or the vascular endothelium was observed.

Conclusion

Our findings suggest that using the optimized protocol presented in this paper allows good cryopreservation of whole human ovaries and represents an important step in considering whole ovary autotransplantation for clinically applied fertility preservation.

Recent advances in the field of ovarian tissue cryopreservation and opportunities for research

PURPOSE

The purpose of this study was to summarize the latest advances and successes in the field of ovarian tissue cryopreservation while identifying gaps in current knowledge that suggest opportunities for future research.

METHODS

A systematic review was performed according to PRISMA guidelines for all relevant full-text articles in PubMed published in English that reviewed or studied historical or current advancements in ovarian tissue cryopreservation and auto-transplantation techniques.

RESULTS

Ovarian tissue auto-transplantation in post-pubertal women is capable of restoring fertility with over 80 live births currently reported with a corresponding pregnancy rate of 23 to 37%. The recently reported successes of live births from transplants, both in orthotopic and heterotopic locations, as well as the emerging methods of in vitro maturation (IVM), in vitro culture of primordial follicles, and possibility of in vitro activation (IVA) suggest new fertility options for many women and girls. Vitrification, as an ovarian tissue cryopreservation technique, has also demonstrated successful live births and may be a more cost-effective method to freezing with less tissue injury. Further, transplantation via the artificial ovary with an extracellular tissue matrix (ECTM) scaffolding as well as the effects of sphingosine-1-phosphate (SIP) and fibrin modified with heparin-binding peptide (HBP), heparin, and a vascular endothelial growth factor (VEGF) have demonstrated important advancements in fertility preservation. As a fertility preservation method, ovarian tissue cryopreservation and auto-transplantation are currently considered experimental, but future research may pave the way for these modalities to become a standard of care for women facing the prospect of sterility from ovarian damage.

Chapter 15 Development of a Nationwide Network for Ovarian Tissue Cryopreservation

Ovarian tissue cryopreservation is gaining much interest since the publication of the first live birth after retransplantation of frozen-thawed tissue in 2004 (Donnez et al., Lancet 364:1405-1410, 2004). In contrast to cryopreservation of gametes and embryos, ovarian tissue freezing is a complex requiring a proper approach in order to make this a viable option for fertility preservation of cancer patients. Due to the need in terms of laboratory space, equipment, personnel, and adequate logistics, an ovarian tissue cryobank is most economic if managed as a centralized service unit that interacts with numerous clinics covering the surgical part. Transportation of ovarian tissue under appropriate conditions from the surgical unit to the cryobank for subsequent preparation and freezing has been shown to have no impact on cryo-survival (Schmidt et al., Hum Reprod 18:2654-2659, 2003; Isachenko et al., Fertil Steril 91:1556-1559, 2009). Several children have been born after retransplantation of such tissue that was derived from the cryobank in Bonn, Germany (Homepage FertiPROTEKT. http://www.fertiprotekt.de ). This cryobank is one of the largest in the world with more than 1300 tissue samples that were frozen from 2003 until today. It is integrated in the network FertiPROTEKT (Homepage FertiPROTEKT. http://www.fertiprotekt.de ) and is served by 108 surgical centers that are located all over Germany. The concept of this cryobank is a blueprint for success and has recently been used for another regionally centralized cryobank in Beijing, China. In this chapter the most important topics that need to be considered while creating a centralized cryobank within a national or regional network are highlighted.

Practices and Attitudes Regarding Women Undergoing Fertility Preservation: A Survey of the National Physicians Cooperative

PURPOSE

To describe physician attitudes and variations in oncofertility treatment strategies.

METHODS

An exploratory online survey administered between December 1, 2014 and January 27, 2015 to 185 members of the National Physicians Cooperative (NPC).

RESULTS

Twenty-eight percent (52 of 185) of NPC members responded to the online survey. Fifty percent of respondents were obstetrician-gynecologists working largely in academic medical centers. Thirty-eight percent stated that 14 was the youngest age they felt comfortable performing oocyte retrievals with 35% stating that any age was acceptable as long as they were postpubertal. Short stimulation protocols, utilizing a gonadotropin-releasing hormone (GnRH) antagonist (86%), were more common than long stimulation or microdose Lupron flare protocols (23% and 18%), respectively, which utilize a GnRH agonist. Random start protocols were used by 77% and over 90% perform luteal phase starts. When using random start protocols, 64% use gonadotropins only and 32% start GnRH antagonists alone for several days before starting gonadotropins. Fifty-five percent of physicians were comfortable stimulating ovarian cancer patients only after clearance from an oncologist. Aromatase inhibitors (77%) were significantly more common than tamoxifen (24%) for stimulation in breast cancer patients (p = 0.0006). When considering ovarian stimulation after chemotherapy, 24% expressed comfort only if blood counts are normal, 38% tend to wait 3 months. Regarding experimental treatment, 83% report discussing the use of GnRH agonists alone and 64% of clinics offer ovarian tissue cryopreservation.

CONCLUSIONS

This study underlines the wide variation that exists in stimulation and phase start techniques, patient selection, comfort levels, and cancer type-specific decision making.

Ovarian fragment sizes affect viability and morphology of preantral follicles during storage at 4°C

The method of transportation and the conditions imposed on the ovarian tissue are pivotal aspects for the success of ovarian tissue cryopreservation (OTC). The aim of this study was to evaluate the effect of the size of the ovarian tissue (e.g. whole ovary, biopsy size and transplant size) during different times of storage (0, 6, 12 and 24 h) on the structural integrity of equine ovarian tissue transported at 4°C. Eighteen pairs of ovaries from young mares (<10 years old) were harvested in a slaughterhouse and processed to simulate the fragment sizes (biopsy and transplant size groups) or kept intact (whole ovary group) and stored at 4°C for up to 24 h in α-MEM-enriched solution. The effect of the size of the ovarian tissue was observed on the morphology of preantral follicles, stromal cell density, DNA fragmentation and mitochondrial membrane potential. The results showed that (i) biopsy size fragments had more morphologically normal preantral follicles after 24 h of storage at 4°C; (ii) mitochondrial membrane potential was the lowest during each storage time when the whole ovary was used; (iii) DNA fragmentation rate in the ovarian cells of all sizes of fragments increased as storage was prolonged and (iv) transplant size fragments had increased stromal cell density during storage at cool temperature. In conclusion, the biopsy size fragment was the best to preserve follicle morphology for long storage (24 h); however, transportation/storage should be prior determined according to the distance (time of transportation) between patient and reproduction centers/clinics.

Operative techniques and complications of extraction and transplantation of ovarian tissue: the Erlangen experience

PURPOSE

Extracting ovarian tissue before oncologic therapy and transplanting it afterwards are increasingly being used to preserve fertility in women. This study describes standardized and safe operative procedures, with few complications, and reports the resulting ovarian function and pregnancy rates.

METHODS

The standardized operative techniques for removing and transplanting ovarian tissue used at the Erlangen center are: for tissue removal, one-third to half of the tissue from one ovary is excised with scissors, without tissue coagulation; for subsequent transplantation, pieces of ovarian tissue are placed in a retroperitoneal pocket without closure of the pocket.

RESULTS

Between January 2007 and December 2015, ovarian tissue was extracted in 399 women and transplanted following cancer therapy in 38. No surgical complications were observed within 28 days. To date, there have been ten pregnancies and nine live births after transplantation in seven different women; 26 of the 38 women developed hormonal activity, confirmed by a menstrual cycle or raised serum estradiol levels.

CONCLUSIONS

The techniques for laparoscopic removal and transplantation of ovarian tissue described here provide a standardized method with a very low risk of complications. The pregnancy rate after ovarian tissue transplantation, currently 15-30%, can be expected to rise further in the near future.

86 successful births and 9 ongoing pregnancies worldwide in women transplanted with frozen-thawed ovarian tissue: focus on birth and perinatal outcome in 40 of these children

PURPOSE

This study aims to make an account of the children born following transplantation of frozen-thawed ovarian tissue worldwide with specific focus on the perinatal outcome of the children. Furthermore, perinatal outcome of seven deliveries (nine children) from Denmark is reported.

METHODS

PubMed was searched for papers of deliveries resulting from ovarian tissue cryopreservation (OTC). Seven women underwent OTC prior to chemotherapy. Four of these women still had low ovarian function and had tried to conceive. They therefore had tissue autotransplanted to augment their fertility. The other three women had developed premature ovarian insufficiency (POI) after the end of treatment.

RESULTS

Worldwide, approximately 95 children have been born or will be born in the near future from OTC, including these 9 new children. Information on the perinatal outcome was found on 40 children. The mean gestational age was 39 weeks and the mean birth weight was 3168 g of the singleton pregnancies, which is within internationally recognized normal standards. Furthermore, half the singletons resulted from natural conception and all twins resulted from in vitro fertilization treatment. All seven Danish women became pregnant within 1-3 years after transplantation. They gave birth to nine healthy children.

CONCLUSION

The data is reassuring and further suggests that cryopreservation of ovarian tissue is becoming an established fertility preservation method. The seven Danish women reported in this study were all in their early thirties when OTC was performed. Most other reported cases were in the women's twenties. This suggests that the follicular pool in the thirties is large enough and sufficient to sustain fertility.

Ovarian tissue cryopreservation and transplantation: scientific implications

After fresh or frozen ovary transplantation, FSH levels return to normal, and menstrual cycles resume by 150 days, coincident with anti-Müllerian hormone rising to higher than normal levels. AMH then returns to well below normal levels by 240 days, remaining as such for many years with nonetheless normal ovulation and fertility. To date, 20 babies have been born in our program from 11 fresh and 13 cryopreserved ovary transplant recipients with a live baby rate of over 70 % (11 babies from fresh and 9 from frozen). Globally, over 70 live births have been reported for both fresh and frozen ovary transplants with an approximate 30 % live birth rate. Given the rapid rise of AMH after the fall of FSH, with a subsequent AMH decrease with retention of ovarian function, it is tempting to speculate the existence of a shared mechanism controlling primordial follicle recruitment, fetal oocyte meiotic arrest, and recruitment in the adult ovary. With the massive recruitment of primordial follicles observed after human ovarian cortical tissue transplantation, which subsides to an extremely low recruitment rate, we will discuss how this phenomenon suggests a unifying theory implicating ovarian cortical tissue rigidity in the regulation of both fetal oocyte arrest and recruitment of follicles in the adult ovary. As the paper by Winkler-Crepaz et al. in this issue demonstrates, our in vivo results are consistent with the in vitro demonstration that primordial follicles in the fetal cortex are "locked" in development, resulting in meiotic arrest, which spares the oocytes from being rapidly lost all at once (Winkler-Crepaz et al., J Assist Reprod Genet, 1). Winkler-Crepaz et al. demonstrate that follicle loss after ovarian cortex transplantation is unlikely due to ischemic apoptosis, but rather from a "burst" of primordial follicle recruitment. In vivo, primordial follicles are normally resistant to further development or activation to prevent oocyte depletion. The dense fibrous ovarian cortex, through as yet unresolved mechanisms, arrests the further continuation of meiosis and also prevents a sudden depletion of all resting follicles in the adult ovary. Intrinsic tissue pressure is released after cortical tissue transplantation, temporarily resulting in a rapid follicle depletion. These results are consistent with the observation that once the ovarian reserve is reduced in the graft, the rate of recruitment diminishes and the ovarian tissue exhibits a relatively long duration of function.

Clinically applied procedures for human ovarian tissue cryopreservation result in different levels of efficacy and efficiency

PURPOSE

Different protocols are being used worldwide for the cryopreservation of human ovarian tissue for fertility preservation purposes. The efficiency and efficacy of the majority of these protocols has not been extensively evaluated, possibly resulting in sub-optimally cryopreserved ovarian tissue. To address the impact of this issue, we assessed the effects of two clinically successful human ovarian tissue slow-freezing cryopreservation procedures on the quality of the cryopreserved tissue.

METHODS

To differentiate between cryopreservation (_C) versus thawing (_T) related effects, four combinations of these two (A and B) very different cryopreservation/thawing protocols (A_CA_T, A_CB_T, B_CA_T, B_CB_T) were studied. Before and after cryopreservation and thawing, the percentage of living and morphologically normal follicles, as well as the overall tissue viability, was assessed.

RESULTS

Our experiments revealed that the choice of the cryopreservation protocol noticeably affected the overall tissue viability and percentage of living follicles, with a higher viability after protocol B_C when compared to A_C. No statistically significant differences in tissue viability were observed between the two thawing protocols, but thawing protocol B_T required considerably more human effort and materials than thawing protocol A_T. Tissue morphology was best retained using the B_CA_T combination.

CONCLUSION

Our results indicate that extensive and systematical evaluation of clinically used protocols is warranted.