Autotransplantation of cryopreserved ovarian tissue after treatment for malignant disease - the first Norwegian results

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.

Roles of follicle stimulating hormone and sphingosine 1-phosphate co-administered in the process in mouse ovarian vitrification and transplantation

Some major challenges of ovarian tissue vitrification and transplantation include follicle apoptosis induced by cryopreservation and ischemia-reperfusion injury, as well as ovarian follicle loss during post-transplantation. This research aimed to investigate the protective effects and underlying mechanisms of follicle-stimulating hormone (FSH) and Sphingosine-1-phosphate (S1P) on vitrified and post-transplantation ovaries. Ovaries from 21-day-old mice were cryopreservation by vitrification with 0.3 IU/mL FSH, 2 µM S1P, and 0.3 IU/mL FSH + 2 µM S1P, respectively, for follicle counting and detection of apoptosis-related indicators. The results demonstrated that FSH and S1P co-intervention during the vitrification process could preserve the primordial follicle pool and inhibit follicular atresia by suppressing cell apoptosis. The thawed ovaries were transplanted under the renal capsule of 6-8 week-old ovariectomized mice and removed 24 h or 7 days after transplantation. The results indicated that FSH and S1P co-intervention can inhibit apoptosis and autophagy in ovaries at 24 h after transplantation, and promote follicle survival by up-regulating Cx37 and Cx43 expression, enhanced angiogenesis in transplanted ovaries by promoting VEGF expression, as well as increased the E2 levels to restore ovarian endocrine function at 7 days after transplantation. The hypoxia and ischemia cell model was established by CoCl2 treatment for hypoxia in human granulosa-like tumor cell line (KGN), as well as serum-free culture system was used for ischemia. The results confirmed that ischemia-hypoxia-induced apoptosis in ovarian granulosa cells was reduced by FSH and S1P co-intervention, and granulosa cell autophagy was inhibited by up-regulating the AKT/mTOR signaling pathway. In summary, co-administration of FSH and S1P can maintain ovarian survival during ovarian vitrification and increase follicle survival and angiogenesis after transplantation.

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

BACKGROUND

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

OBJECTIVE AND RATIONALE

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

SEARCH METHODS

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

OUTCOMES

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

WIDER IMPLICATIONS

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

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

OBJECTIVE

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

DESIGN

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

SETTING

Not applicable.

PATIENT(S)

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

INTERVENTION(S)

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

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].

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

OBJECTIVE

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

DESIGN

Case series with meta-analytic update.

SETTING

Academic.

PATIENT(S)

Seven recipients of RA-ACOTT.

INTERVENTION(S)

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

Methods of Ovarian Tissue Cryopreservation: Is Vitrification Superior to Slow Freezing?-Ovarian Tissue Freezing Methods

After cancer treatment, female survivors often develop ovarian insufficiency or failure. Oocyte and embryo freezing are well-established fertility preservation options, but cannot be applied in pre-pubescent girls, in women with hormone-sensitive malignancies, or when gonadotoxic treatment cannot be delayed. Although ovarian tissue cryopreservation (OTC) has been used to restore fertility and endocrine function, the relative efficacy of its two major protocols, slow freezing and vitrification, remains controversial. This literature review evaluates clinical and lab-based studies published between January 2012 and June 2020 to determine whether vitrification, the optimal technique for oocyte and embryo cryopreservation, preserves ovarian tissue more effectively than slow freezing. Due to limited clinical data involving ovarian tissue vitrification, most clinical studies focus on slow freezing. Only 9 biochemical studies that directly compare the effects of slow freezing and vitrification of human ovarian tissue were noted. Most studies report no significant difference in follicular morphology and distribution between cryopreservation methods, but these findings must be interpreted in the context of high methodological variability. Discrepant findings regarding the effects of cryopreservation method on follicle viability, gene expression, and hormone production require further evaluation. Early clinical outcomes appear favorable for vitrification, but additional studies and longer term follow-up are needed to establish its efficacy. Sharing data through national or international registries would expedite this analysis. However, even if research corroborates conclusions of no clinical or biochemical difference between cryopreservation methods, the decreased costs and increased efficiency associated with vitrification make this method more accessible and cost-effective.

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

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

Spatial and temporal changes in follicle distribution in the human ovarian cortex

RESEARCH QUESTION

How does follicle distribution evolve in the human ovarian cortex between the ages of 20 and 35 years?

DESIGN

Fragments of ovarian cortex from women undergoing unilateral oophorectomy for fertility preservation were obtained for quantitative histological assessment, including recording the two-dimensional coordinates of the follicles. Data were analysed using spatial statistical methods.

RESULTS

A total of 53 ovarian cortex tissue samples, containing 1-803 follicles each, were obtained from 14 women aged 20-35 years. Primordial and transitory follicles lay in a clustered manner in the human ovarian cortex, with an average cluster radius of around 270 µm (95% confidence interval 154-377 µm; n = 49). Follicle density declined with age (P = 0.006, n = 13), and the distance from the nearest neighbouring follicle increased (P = 0.004, n = 13). Cluster radius decreased with age (P = 0.02, n = 13), but the degree of clustering tended to increase (P = 0.11, n = 13). In the majority of the samples, follicles at different stages lay in different clusters (P < 0.05, n = 13).

CONCLUSIONS

This study shows that primordial and transitory follicles lie in different clusters in the human ovarian cortex. Spatio-temporal computer simulation suggests that interfollicular signals may hinder follicle loss and may therefore drive clustered follicle distribution. In clinical practice, the woman's age should be taken into account when assessing follicle density, as follicle distribution is increasingly clustered with advancing age.

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.

A case report and follow-up of the first live birth after heterotopic transplantation of cryopreserved ovarian tissue in Eastern Europe

Background

Ovarian insufficiency is a major concern for long-term cancer survivors. Although semen freezing is well established to preserve male fertility, the possibilities to secure post-cancer female fertility are mostly limited to oocyte or embryo freezing. These methods require time-consuming ovarian stimulation with or without in vitro fertilization (IVF) that evidently delays cancer therapy. Ovarian tissue cryopreservation and subsequent thawed tissue autotransplantation are considered the most promising alternative strategy for restoring the fertility of oncology patients, which has not yet received the full clinical acceptance. Therefore, all successful cases are needed to prove its reliability and safety.

Case presentation

Here we report a single case in Estonia, where a 28-year-old woman with malignant breast neoplasm had ovarian cortex cryopreserved before commencing gonadotoxic chemo- and radiotherapy. Two years after cancer therapy, the patient underwent heterotopic ovarian tissue transplantation into the lateral pelvic wall. The folliculogenesis was stimulated in the transplanted tissue by exogenous follicle-stimulating hormone and oocytes were collected under ultrasound guidance for IVF and embryo transfer. The healthy boy was born after full-term gestation in 2014, first in Eastern Europe.

Conclusion

Despite many countries have reported the first implementation of the ovarian tissue freezing and transplantation protocols, the data is still limited on the effectiveness of heterotopic ovarian transplant techniques. Thus, all case reports of heterotopic ovarian tissue transplantation and long-term follow-ups to describe the children’s health are valuable source of clinical experience.

Fertility preservation in ovarian tumours

A considerable number of patients with a cancer diagnosis are of childbearing age and have not satisfied their desire for a family. Despite ovarian cancer (OC) usually occurring in older patients, 3%-14% are diagnosed at a fertile age with the overall 5-year survival rate being 91.2% in women ≤44 years of age when it is found at 1A-B stage. In this scenario, testing the safety and the efficacy of fertility sparing strategies in OC patients is very important overall in terms of quality of life. Unfortunately, the lack of randomised trials to validate conservative approaches does not guarantee the safety of fertility preservation strategies. However, evidence-based data from descriptive series suggest that in selected cases, the preservation of the uterus and at least one part of the ovary does not lead to a high risk of relapse. This conservative surgery helps to maintain organ function, giving patients of childbearing age the possibility to preserve their fertility. We hereby analysed the main evidence from the international literature on this topic in order to highlight the selected criteria for conservative management of OC patients, including healthy BRCA mutations carriers.

Transplantation of frozen-thawed ovarian tissue: an update on worldwide activity published in peer-reviewed papers and on the Danish cohort

PURPOSE

The purpose of the study is to review all peer-reviewed published reports of women receiving ovarian tissue transplantation (OTT) with frozen/thawed tissue (OTC) with respect to age, diagnosis, transplantation site, fertility outcome, and potential side effects, including data from all women in the Danish program.

METHODS

A systematic review of the literature was performed in PubMed combined with results from all patients who had received OTT in Denmark up to December 2017.

RESULTS

OTT has been reported from 21 different countries comprising a total of 360 OTT procedures in 318 women. In nine women, malignancy was diagnosed after OTT; none were considered to be directly caused by the OTT. Despite a potential under reporting of cancer recurrence, there is currently no evidence to suggest that OTT causes reseeding of the original cancer. Renewed ovarian endocrine function was reported in 95% of the women. Half of all children born following OTT resulted from natural conception, and newborns were reported to be healthy except for one neonate with a chromosome anomaly with a family disposition. Women who conceived after OTT were significantly younger than those who failed.

CONCLUSION

This study found no indications of sufficient numbers of malignant cells present in the ovarian tissue to cause recurrence of cancer after OTT. Further, it is unlikely that OTC affects the well-being of children born. OTC is now an established method of fertility preservation in Denmark with public reimbursement. The current data encourage that women who require gonadotoxic treatment should be offered an individual evaluation considering fertility preservation.

Fertility preservation in BRCA-mutated women: when and how?

BRCA 1 and 2 genes play a critical role in the safeguarding of DNA integrity. It is now well established that BRCA1 and BRCA2-mutated women are at increased risk of breast and ovarian cancers. However, several lines of evidence indicate that this genetic status may also be associated with ovarian dysfunction, in particular a reduced ovarian reserve. Considering the gonadal toxicity of cancer treatments and the recommendation of prophylactic bilateral salpingo-oophorectomy around 40 years, young BRCA mutation carriers are confronted with difficult family planning decisions. Recent development in fertility preservation offers new possibilities for these women, not only before a potential cancer treatment, but also in healthy carriers. If the pregnancy seems to be safe in this population, oocyte vitrification following ovarian stimulation might help BRCA-mutated patients to conceive after cancer treatment or to undergo prenatal genetic diagnosis in order to avoid the risk of transmitting the genetic abnormality to their offspring. The present article aims to extensively discuss the fertility issues related to BRCA gene mutations and the questions raised by the possibility of fertility in this population.

Current Success and Efficiency of Autologous Ovarian Transplantation: A Meta-Analysis

CONTEXT

Ovarian cryopreservation followed by autotransplantation is still considered an experimental strategy for fertility preservation (FP) mainly because the success rates are unknown.

OBJECTIVE

To determine cohort epidemiologic characteristics and success rates of autologous ovarian tissue transplantation (OTT) with previously cryopreserved tissue.

MATERIALS AND METHODS

Literature review from 1999 to October 1, 2016. Additional cases were retrieved from meeting abstracts and own database. We selected studies that reported autologous OTT with previously banked tissue in humans. We did not include any cases involving fresh ovarian tissue transplantation or those performed to treat idiopathic premature ovarian failure/insufficiency. Both authors reviewed and selected studies for eligibility, which resulted in 59 full-text studies assessed for eligibility. Cases were extracted from original reports and reviews by the junior author, and the senior author reviewed and verified the extracted data.

RESULTS

Nineteen reports were included for qualitative synthesis. In 10 studies, detailed data were available to determine clinical and live birth + ongoing (LB + OG) pregnancy as well as endocrine restoration rates. Three hundred nine OTTs were performed with cryopreserved tissue, resulting in the birth of 84 children and 8 OG pregnancies. The cumulative clinical and LB + OG rates were 57.5% and 37.7%, respectively, and the endocrine restoration rate was 63.9%.

CONCLUSION

Success rates with cryopreserved OTT have reached promising levels. Given these recent data, ovarian tissue cryopreservation should be considered as a viable option for FP.

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 among alternatives for fertility preservation in the Nordic countries - compilation of 20 years of multicenter experience

Introduction

The aim of this study is to report the current status of ovarian tissue cryopreservation among alternatives for fertility preservation in the Nordic countries.

Material and methods

A questionnaire was sent to 14 Nordic academic reproductive centers with established fertility preservation programs. It covered fertility preservation cases performed up to December 2014, standard procedures for ovarian tissue cryopreservation and oocyte cryopreservation and reproductive outcomes following ovarian tissue transplantation.

Results

Among the Nordic countries, Denmark and Norway practice ovarian tissue cryopreservation as a clinical treatment (822 and 164 cases, respectively) and their programs are centralized. In Sweden (457 cases), ovarian tissue cryopreservation is practiced at five of six centers and in Finland at all five centers (145 cases). Nearly all considered ovarian tissue cryopreservation to be experimental. In Iceland, embryo cryopreservation is the only option for fertility preservation. Most centers use slow‐freezing methods for ovarian tissue cryopreservation. Most patients selected for ovarian tissue cryopreservation were newly diagnosed with cancer and the tissue was predominantly retrieved laparoscopically by unilateral oophorectomy. Only minor complications were reported. In total, 46 women have undergone ovarian tissue transplantation aiming at recovering fertility, 17 healthy children have been born and several additional pregnancies are currently ongoing. Whenever patients’ clinical condition is permissive, oocyte cryopreservation after hormonal stimulation is preferred for fertility preservation. Between 2012 and 2014, a smaller proportion of females have undergone fertility preservation in the Nordic centers, in comparison to males (1:3).

Conclusions

Overall, ovarian tissue cryopreservation was reported to be safe. Slow freezing methods are still preferred. Promising results of recovery of fertility have been reported in Nordic countries that have initiated ovarian tissue transplantation procedures.

First pregnancies, live birth, and in vitro fertilization outcomes after transplantation of frozen-banked ovarian tissue with a human extracellular matrix scaffold using robot-assisted minimally invasive surgery

BACKGROUND

Ovarian tissue cryopreservation is an experimental fertility preservation method and the transplantation techniques are still evolving.

OBJECTIVE

We attempted to improve the technique with the utility of a human decellularized extracellular tissue matrix (ECTM) scaffold, robot-assisted minimally invasive surgery, and perioperative pharmacological support.

STUDY DESIGN

We prospectively studied 2 subjects with hemophagocytic lymphohistiocytosis (patient A) and non-Hodgkin lymphoma (patient B) who underwent ovarian tissue cryopreservation at the age of 23 years, before receiving preconditioning chemotherapy for hematopoietic stem cell transplantation. Both experienced ovarian failure postchemotherapy and we transplanted ovarian cortical tissues to the contralateral menopausal ovary 7 and 12 years later, using a human ECTM scaffold and robotic assistance. The ECTM scaffold tissue compatibility was shown in preclinical studies. Patients also received estrogen supplementation and baby aspirin preoperatively to aid in the revascularization process.

RESULTS

Ovarian follicle development was observed approximately 10 (patient A) and 8 (patient B) weeks after ovarian tissue transplantation. Following 8 and 7 cycles of in vitro fertilization, 9 and 10 day-3 embryos were cryopreserved (patients A and B, respectively). While the baseline follicle-stimulating hormone (range 3.6-15.4 mIU/mL) levels near normalized by 7 months and remained steady postovarian transplantation in patient A, patient B showed improved but elevated follicle-stimulating hormone levels throughout (range 21-31 mIU/mL). Highest follicle yield was achieved 14 (8 follicles; patient A) and 11 (6 follicles; patient B) months postintervention. Patient A experienced a chemical pregnancy after the third frozen embryo transfer attempt. She then conceived following her first fresh in vitro fertilization embryo transfer and the pregnancy is currently ongoing. Patient B conceived after the first frozen embryo transfer attempt and delivered a healthy girl at term.

CONCLUSION

We report the first pregnancies after the minimally invasive transplantation of previously cryopreserved ovarian tissue with an ECTM scaffold. This approach seems to be associated with steady ovarian function after a follow-up of up to 2 years.

Impact of the cryopreservation technique and vascular bed on ovarian tissue transplantation in cynomolgus monkeys

PURPOSE

The aim of this study was to determine the best combination in terms of cryopreservation techniques and vascular bed preparation before grafting in order to obtain functional ovarian tissue after transplantation.

METHODS

Five cynomolgus monkeys were used. Strips from 10 ovaries were cryopreserved, 5 by vitrification (V), and 5 by slow-freezing (SF). Pieces of fresh ovarian tissue were used for controls. After 1 month, the strips were autografted to two different vascular beds, healed (HB) or freshly decorticated (FDB), constituting four study groups: SF-HB, SF-FDB, V-HB, and V-FDB. These were compared to fresh tissue. After 6 months, the ovaries were removed and several parameters analyzed: follicle quality, stage, density, proliferation, apoptosis, functionality, vascularization, and fibrosis. Mixed effect linear regression models were built to assess the impact of cryopreservation and vascular bed preparation on ovarian tissue viability and functionality. p values were adjusted for multiple testing using the Benjamini-Hochberg method, and q values < 0.20 were considered significant in order to achieve a 20% false discovery rate.

RESULTS

Compared to fresh tissue, no difference was observed in the percentage of morphologically normal follicles, while a significant increase was noted in the follicle proliferation rate (41%, q = 0.19), percentage of antral follicles (12%, q = 0.14), and number of vessels per area (3.3 times, q = 0.07) in the V-FDB group.

CONCLUSIONS

Vitrification associated with FDB vascular bed preparation is the best combination to obtain functional autografted ovarian tissue. Further studies are nevertheless required, with confirmed pregnancies and live births before introducing the procedure into clinical practice.

Ovarian cortex transplantation: 60 reported live births brings the success and worldwide expansion of the technique towards routine clinical practice

This paper describes the success and expansion of ovarian tissue cryopreservation and transplantation as a fertility restoration procedure, with the largest series of 60 live births worldwide reported. By repeating the procedure, ovarian activity can be restored for more than 11 years.