Efficacy of ovarian tissue cryopreservation in a major European center

Evaluating the safety and efficacy of cryopreserved ovarian tissue transplantation in leukemia patients with different bone marrow remission status using xenotransplantation

Background

Leukemia patients undergoing cryopreserved ovarian tissue transplantation (OTT) may carry a high risk of disease induction. Measurable residual disease (MRD) in bone marrow is linked to an elevated risk of relapse. It is controversial whether leukemia patients must be allowed to achieve measurable residual disease negative (MRD-negative) status instead of measurable residual disease positive (MRD-positive) status before ovarian tissue cryopreservation (OTC).

Objective

To explore the safety and efficacy of OTT in acute leukemia patients with different MRD status by using xenotransplantation.

Method

Cryopreserved ovarian tissue from 19 leukemia patients was thawed and xenotransplanted to ovariectomized BALB/C nude mice (n=36). The mice were divided into 2 groups based on the patient's MRD status before OTC: MRD-negative group (n=18) and MRD-positive group (n=18), additionally, a control group consisted of ovariectomized mice (n=9). Body weight was measured weekly and mortality, emaciation, and other abnormalities were recorded. Twenty-six weeks post-surgery, livers, spleens, uteruses, and ovarian grafts were removed for macroscopic and histological examinations to evaluate the efficacy of xenotransplantation and assess malignant cell contamination in mice.

Results

Follicle growth was visible in the ovarian grafts of the MRD-negative and MRD-positive groups. Compared with the ovariectomized group, a significant decrease in body weight (p<0.01) was noted, the uterine volume was notably larger, estradiol (E2) levels were significantly higher (p<0.01), and follicle-stimulating hormone (FSH) levels were significantly lower (p<0.001) in the other two groups. Mice in the MRD-positive group showed a significantly higher incidence of death (p<0.001) and emaciation (p<0.01), compared to the MRD-negative group. Histological observation revealed the presence of malignant cells in the grafts, livers, and spleens of 3 mice in the MRD-positive group. No abnormalities were observed in the mice from the MRD-negative group in both macroscopic and histological observations except one mouse was sacrificed for ascites unrelated to leukemia relapse.

Conclusion

For leukemia patients having ovarian tissue preserved in the first and only centralized human ovarian tissue cryobank in China, immunodeficient mice xenotransplantation can be a method to evaluate the safety and efficacy of OTT; the risk of malignant cell reimplantation due to OTT is higher in leukemia patients with MRD-positive status than those with MRD-negative status before OTC.

Comparative effects of a calcium chelator (BAPTA-AM) and melatonin on cryopreservation-induced oxidative stress and damage in ovarian tissue

Oncology treatments cause infertility, and ovarian tissue cryopreservation and transplantation (OTCT) is the only option for fertility preservation in prepubertal girls with cancer. However, OTCT is associated with massive follicle loss. Here, we aimed to determine the effect of supplementation of slow freezing and vitrification media with BAPTA-AM and melatonin alone and in combination on ovarian tissue viability, reactive oxygen species (ROS) levels, total antioxidant capacity (TAC), and follicular morphology and viability. Our results indicated that BAPTA-AM and melatonin can significantly improve ovarian tissue viability and the TAC/ROS ratio and reduce ROS generation in frozen-thawed ovarian tissues in slow freezing and vitrification procedures. BAPTA-AM was also found to be less effective on TAC compared to melatonin in vitrified ovarian tissue. While supplementation of slow freezing and vitrification media with BAPTA-AM and/or melatonin could increase the percentage of morphologically intact follicles in cryopreserved ovarian tissues, the differences were not significant. In conclusion, supplementation of cryopreservation media with BAPTA-AM or melatonin improved the outcome of ovarian tissue cryopreservation in both vitrification and slow freezing methods. Our data provide some insight into the importance of modulating redox balance and intracellular Ca2+ levels during ovarian tissue cryopreservation to optimize the current cryopreservation methods.

Nanowarming improves survival of vitrified ovarian tissue and follicular development in a sheep model

Tissue cryopreservation has allowed long term banking of biomaterials in medicine. Ovarian tissue cryopreservation in particular helps patients by extending their fertility window. However, protection against tissue injury during the thawing process has proven to be challenging. This is mainly due to the heterogenous and slow distribution of the thermal energy across the vitrified tissue during a conventional warming process. Nanowarming is a technique that utilizes hyperthermia of magnetic nanoparticles to accelerate this process. Herein, hyperthermia of synthesized PEGylated silica-coated iron oxide nanoparticles was used to deter the injury of cryopreserved ovarian tissue in a sheep model. When compared to the conventional technique, our findings suggest that follicular development and gene expression in tissues warmed by the proposed technique have been improved. In addition, Nanowarming prevented cellular apoptosis and oxidative stress. We therefore conclude that Nanowarming is a potential complementary candidate to increase efficiency in the ovarian cryopreservation field.

Effects of hypoxia-preconditioned HucMSCs on neovascularization and follicle survival in frozen/thawed human ovarian cortex transplanted to immunodeficient mice

Background

The massive loss of follicles in the early stage of ovarian tissue transplantation is considered a significant restriction to the efficacy of ovarian tissue cryopreservation (OTC) and transplantation (OT). The use of mesenchymal stem cells (MSCs) before transplantation of ovarian fragments shortened the hypoxic period and boosted neovascularization. Hypoxia-preconditioned MSCs can enhance the potential of angiogenesis. Can hypoxia-preconditioned human umbilical cord mesenchymal stem cell (HucMSCs) and ovarian tissue co-xenotransplantation improve more neovascularization and subsequently more follicle survival in human ovarian tissue?

Methods

Frozen-thawed cortical pieces from 4 patients were transplanted into the bilateral renal capsule of immune-deficient nude mice without HucMSCs or normoxia/hypoxia-preconditioned HucMSCs. Sixty-four mice were randomly distributed into 4 groups. In each group, the mice were euthanized for blood and/or graft retrieval on post-transplantation days 3 (n = 8) and 7 (n = 8), respectively. Non-grafted frozen-thawed ovarian fragment was taken for non-grafted control. Grafts were histologically processed and analysed for follicle density and atretic follicles by HE, neovascularization by CD34 and CD31 immunohistochemical staining, primordial follicle growth by Ki67 staining, and apoptosis of stromal cell and follicles by immunofluorescence using TUNEL. The ROS and TAC levels of grafted and non-grafted tissue were assessed. We evaluated the protein expression of HIF1α, VEGFA, pAkt, Akt, and GDF9 in grafted and non-grafted ovarian tissue. E2, Prog, AMH, and FSH levels in the plasma of mice were measured after 3 and 7 days of OT.

Results

Hypoxia-preconditioned HucMSCs positively protect the grafted ovarian tissue by significantly decreasing the apoptosis and increasing higher expression of CD31, CD34, and VEGFA for earlier angiogenesis. They are crucial to preserving the resting primordial follicle pool by modulation of follicle death.

Conclusion

This is the first study to demonstrate that co-transplantation of hypoxia-preconditioned HucMSC with ovarian tissue improved earlier vascularization of ovarian grafts in the early post-grafting period, which correlates with increased follicle survival and reduced apoptosis. The HIF1α/VEGFA signal pathways may play an important role in elucidating the mechanisms of action of hypoxia-preconditioned HucMSCs with regard to OT and clinical implementation.

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.

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.

First pregnancy in China after ovarian tissue transplantation to prevent premature ovarian insufficiency

OBJECTIVE

This article reports the first case of pregnancy after frozen-thawed ovarian tissue transplantation to prevent iatrogenic premature ovarian insufficiency in China.

METHODS

Ovarian tissue cryopreservation was performed in a patient with myelodysplastic syndrome (MDS) before multi-agent chemotherapy and hematopoietic stem cell transplantation. Two years later, she showed complete remission from MDS, and six frozen-thawed ovarian tissue strips were transplanted into the peritoneal pocket.

RESULTS

The patient's ovarian activity was restored 3 months after transplantation, and pregnancy occurred spontaneously 27 months after grafting. Until now, the pregnancy has progressed for 30 weeks, and the repeated ultrasound showed normal fetal development.

CONCLUSION

This is the first pregnancy resulting from ovarian tissue cryopreservation and transplantation in China.

N-acetyl-cysteine and the control of oxidative stress during in vitro ovarian follicle growth, oocyte maturation, embryo development and cryopreservation

Oxidative stress is generated by an imbalance between reactive oxygen species (ROS) formation and cellular defense mechanisms. To reduce cellular damage caused by ROS in vivo or in vitro, N-acetyl-cysteine (NAC) is converted into metabolites that have the capacity of stimulating synthesis of glutathione (GSH) which functions directly as free radical scavengers. The NAC antioxidant potential evaluated to the greatest extent is the indirect action of NAC, as a precursor of GSH, with glutathione being the primary antioxidant in cells. During long-term preantral follicle culture, NAC has a synergic action with FSH and an important function in sustaining preantral follicle growth and follicle-cell viability in vitro. The NAC inclusion in in vitro maturation medium for cumulus-oocyte complexes (COC) leads to protection of oocytes from damage induced by heat stress, reductions in ROS, and increases in cumulus cell expansion. Developing embryos are susceptable to oxidative stress because of susceptability to cellular structure damage and not having well-developed defense mechanisms. Results from various indicate there are beneficial effects of NAC on embryonic development by increasing GSH biosynthesis and regulating cell proliferation. In addition, NAC is also an effective antioxidant during cryopreservation of ovarian follicles, oocytes and embryos, because inclusion of NAC in preservation medium leads to improvements in mitochondrial function and cell viability, and reductions in ROS and cellular apoptosis. In this review, there is evaluation of mechanisms of action of NAC and beneficial effects during in vitro culture of preantral follicles, as well as oocyte maturation, embryonic development and cryopreservation.

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.

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.

Reproductive outcomes after in vitro fertilization treatment in a cohort of Danish women transplanted with cryopreserved ovarian tissue

OBJECTIVE

To evaluate ovarian stimulation regimens and reproductive outcomes in a cohort of women undergoing ovarian tissue cryopreservation (OTC) and ovarian tissue transplantation (OTT).

DESIGN

Retrospective cohort study.

SETTING

University hospital and fertility clinics.

PATIENTS

Twenty-eight women undergoing OTT and in vitro fertilization (IVF) from 2012 to 2017.

INTERVENTION

OTC, OTT, and IVF.

MAIN OUTCOME MEASURES

Ovarian stimulation and IVF outcomes.

RESULTS

In total, 99 cycles were performed in 28 patients. In 19 patients responding to stimulation, a median of 3.0 cycles per patient (range: 1-14 cycles) was performed, and 2.0 mature oocytes were retrieved per cycle. The empty follicle rate was 35.9%. Eleven women achieved 15 pregnancies, of which 60% were lost during the first or second trimester, resulting in 5 of 28 women having ≥1 live births, and seven healthy children being born. In breast cancer patients (mean age at OTC: 33.0 years), the pregnancy rates (PR) and live birth rates (LBR) were 35.0% and 5.0% per embryo transfer, respectively. Patients aged ≥34.5 years at OTC all had breast cancer and did not achieve any pregnancies. For all other diagnoses (mean age at OTC: 26.6 years), PR and LBR were 50.0% and 37.5% per embryo transfer, respectively. Collectively, 39% of patients conceived at least once, and 17.9% delivered. Frozen-thawed embryo transfer (FET) resulted in more pregnancies than did fresh embryo transfer.

CONCLUSION

Our results suggest that women of advanced maternal age undergoing OTC and IVF have a poor ovarian reserve, resulting in a poor reproductive outcome. Interestingly, FET appeared to be superior to fresh transfer.

Serum anti-Mullerian hormone (AMH) concentration has limited prognostic value for density of primordial and primary follicles, questioning it as an accurate parameter for the ovarian reserve

OBJECTIVES

To evaluate the prognostic value of anti-Mullerian hormone (AMH) levels in estimating the ovarian density of primordial and primary follicles, which can be assumed to reflect the real ovarian reserve.

STUDY DESIGN

A total of 537 women, average age 30.4 years (range 8.0-43.7 years), underwent ovarian tissue cryopreservation prior to gonadotoxic therapies due to malignant diseases which do not affect ovarian reserve parameters. Standardized ovarian biopsies were obtained, and follicular density was analysed. The prognostic accuracy of serum AMH in estimating ovarian follicle density was evaluated.

MAIN OUTCOME MEASURES

Histologically determined follicle density, AMH serum concentration and their correlation.

RESULTS

In children, follicle density was high but AMH concentration was low. AMH concentration was predicted to be maximum at the age of 15.5 years. In women aged over 15.5 years, the relationship between AMH concentration and follicle density was evaluated. Crude analysis revealed that serum AMH levels and follicular density were moderately correlated (r = 0.34, p < 0.001). From the adjusted regression model the predicted value of follicle density of women aged 20, 30 and 40 years as well as the associated 50 % and 95 % prediction intervals (50 % PI and 95 % PI, respectively) were calculated. For example, for women aged 40 years with a serum AMH level of 1 ng/ml, a follicle density of 2.3/mm³ (50 %PI: [1.1, 4.6]; 95 %PI: [0.3, 18]) was predicted. These large prediction intervals demonstrate the low predictive value of serum AMH for the ovarian follicle density.

CONCLUSIONS

Serum AMH levels have limited prognostic value for the follicle density and therefore for the real ovarian reserve.

Serum anti-Müllerian hormone concentration and follicle density throughout reproductive life and in different diseases—implications in fertility preservation

STUDY QUESTION

How do anti-Müllerian hormone (AMH) serum concentrations and follicle densities (FDs) change with age and disease and what are the implications for fertility preservation?

SUMMARY ANSWER

AMH concentrations and FD do not correlate in young women, and AMH but not FD is reduced in some diseases, limiting the value of AMH as a predictive parameter of ovarian tissue transplantation.

WHAT IS KNOWN ALREADY

AMH is widely used as a parameter to estimate the ovarian reserve. However, the reliability of AMH to predict total number of follicles and the FD is questionable. Women with lymphoma and leukaemia have been shown to have reduced AMH concentrations, but it is unknown if the FD is also reduced. In fertility preservation it is essential to estimate the correct total number of follicles and the FD, as ovarian tissue should only be cryopreserved if ovarian reserve is high. Furthermore, the amount of tissue to be transplanted should be based on the estimation of the real FD.

STUDY DESIGN, SIZE, DURATION

This retrospective observational study included 830 women (mean ± SD age, 28.2 ± 6.81 years; range, 4–43 years) with malignant (n = 806) and benign (n = 24) diseases who cryopreserved tissue in a single centre as part of a national fertility preservation programme. Females with ovarian surgery or known predispositions for a reduced ovarian reserve were excluded. AMH concentrations and FD were evaluated from March 2011 to September 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

AMH concentrations were analysed before gonadotoxic therapies. Standardized biopsies, obtained from different areas of ovarian cortex, were collected. FD was analysed after tissue digestion and calcein staining and was expressed as average number of primordial and primary follicles count per 3 mm biopsy and per cubic millimeter tissue. AMH concentrations and FD were analysed in relation to age and diagnosis group. Both parameters were age adjusted, and associations between the different diagnosis groups and AMH versus FD were assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean ± SD AMH concentration was 3.1 ± 2.81 g/ml, mean FD per 3 mm biopsy was 137 ± 173.9 and 19.4 ± 24.60 per mm3. Maximum AMH concentrations were found in children and teenagers at the age of 6–10 years (5.71 ng/ml) and in adults at the age of 21–25 years (3.33 ng/ml). FD was highest in young children up to an age of 15 years and decreased with increasing age. AMH and FD were not correlated in women ≤20 years and weakly to moderately correlated in women 21–40 years (r = 0.24–0.39). Age-adjusted correlations between AMH and FD were demonstrated in several diagnosis groups such as breast cancer, leukaemia, sarcoma, gastrointestinal cancer and gynaecological cancer but not in the groups exhibiting Hodgkin’s and non-Hodgkin’s lymphoma, cerebral cancer, other types of malignancies and other types of benign diseases. Further statistical analysis supported the finding that, in some diagnosis groups such as Hodgkin’s lymphoma and in gynaecological cancer, AMH concentrations but not FDs are reduced, questioning the prognostic accuracy of AMH for the FD in these diseases.

LIMITATIONS, REASONS FOR CAUTION

Even though biopsies were taken from different sites, heterogenous distribution of follicles might have had some effect on the accuracy of the analysis.

WIDER IMPLICATION OF THE FINDINGS

AMH should be used with care to estimate the total ovarian reserve and FD of cancer patients in young women in some diseases. Therefore, calculating the amount of ovarian tissue to be transplanted based solely on AMH might be inaccurate whereas FD might be a better parameter.

STUDY FUNDING/COMPETING INTEREST(S)

The study did not receive any exterior funding.

Preserving fertility in female patients with hematological malignancies: a multidisciplinary oncofertility approach

Oncofertility is a new interdisciplinary field at the intersection of oncology and reproductive medicine that expands fertility options for young cancer patients. The most common forms of hematological malignancies that occur in girls and young women and therefore necessitate oncofertility care are acute lymphocytic leukemia, acute myeloid leukemia, non-Hodgkin's lymphoma, and Hodgkin's lymphoma. Aggressive gonadotoxic anticancer regimens including alkylating chemotherapy and total body irradiation are used often in treating girls and young women with hematological malignancies. The risks of gonadotoxicity and subsequent iatrogenic premature ovarian insufficiency and fertility loss depend mainly on the type and stage of the disease, dose of anticancer therapy as well as the age of the patient at the beginning of treatment. To avoid or at least mitigate the devastating complications of anticancer therapy-induced gonadotoxicity, effective and comprehensive strategies that integrate different options for preserving and restoring fertility ranging from established to experimental strategies should be offered before, during, and after chemotherapy or radiotherapy. A multidisciplinary approach that involves strong coordination and collaboration between hemato-oncologists, gynecologists, reproductive biologists, research scientists, and patient navigators is essential to guarantee high standard of care.

Ovarian tissue cryopreservation: prospective randomized study on thawed ovarian tissue viability to estimate the maximum possible delivery time of tissue samples

Ovarian tissue cryopreservation is one of the most important methods to protect female fertility, but we just recently established the first central laboratory in China, now building a network with other hospitals. The aim was to estimate the thawed ovarian tissue viability and to explore the feasibility of short-distance transportation. Fifteen samples were obtained from each of 11 patients, i.e. in total 165 samples. One fresh sample was used for follicle counts, 14 punches were cryopreserved, thawed, and randomly divided into seven groups depending on the time after thawing: 0, 20, 40, 60, 80, 100, 120 min. Follicle counts, steroid hormones, and lactate levels were assessed. No significant differences for the three parameters of tissue viability comparing the seven groups were seen. The time can last up to two hours for the delivery of tissue samples from the laboratory to the surgery room. To our knowledge, this question has been tested for the first time systematically within a prospective randomized comparative study.

Steroids and miRNAs in assessment of ovarian tissue damage following cryopreservation

Ovarian cortical tissue cryopreservation is a relatively novel approach to preserving fertility in women diagnosed with cancer. However, the effects of freezing-thawing are not fully understood, mainly due to the lack of suitable methods to assess tissue's survival after thawing. Disparities in steroid production have been associated with ovarian failure by disrupting folliculogenesis, ovulation and oocyte apoptosis. Moreover, specific microRNAs, identified in human ovarian follicles, are thought to play a fundamental role in folliculogenesis. In this study, we investigated the possible interplay between the ovarian steroidal production and microRNA expression patterns in spent culture media, as potential non-invasive markers for ovarian tissue damage after cryopreservation. Cryopreservation of ovarian cortical tissue decreased (P<0.05) both steroid production (oestradiol and progesterone) and expression of microRNA-193b and 320A in spent culture media over 5 days, however, expression of microRNA-24 increased (P<0.05). The number of primordial follicles were also reduced (P<0.05) in fresh-cultured and cryopreserved-cultured cortical tissues when compared with fresh tissues. Downregulation of microRNA-193b and microRNA-320A together with upregulation of microRNA-24 could have a synergistic role in cell apoptosis, and consequently leading to reduced oestradiol and progesterone production. Thus, there appears to be an interplay between these microRNAs, ovarian steroid production and cell damage, which can be further explored as novel non-invasive markers of cell damage following cryopreservation.

A successful multidisciplinary approach for treatment and for preserving the reproductive potential in a rare case of acute lymphocytic leukemia during pregnancy

Leukemia in pregnancy is a rare condition with the prevalence of 1 in 75,000-100,000 pregnancies. In this case report, we present a successful multidisciplinary management strategy for treatment and for preserving the reproductive potential in a rare case of acute lymphocytic leukemia (ALL) during pregnancy. Several complex challenges existed and necessitated a multidisciplinary approach with strong coordination and collaboration between oncologists, gynecologists, reproductive cryobiologists, obstetricians, and neonatologists in order to improve the maternal and fetal outcome. Pregnancy in the second trimester is neither a contraindication for ALL treatment nor for emergency fertility preservation via ovarian tissue extraction and further cryopreservation.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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.

Advances in fertility preservation of female patients with hematological malignancies

INTRODUCTION

The most common forms of hematological malignancies that occur in female reproductive years are lymphoma and leukemia. Areas covered: Several aggressive gonadotoxic regimens such as alkylating chemotherapy and total body irradiation are used frequently in treatment of lymphoma and leukemia leading to subsequent iatrogenic premature ovarian failure and fertility loss. In such cases, female fertility preservation options should be offered in advance. Expert commentary: In order to preserve fertility of young women and girls with lymphoma and leukemia, several established, experimental, and debatable options can be offered before starting chemotherapy and radiotherapy. However, each of those female fertility preservation options has both advantages and disadvantages and may not be suitable for all patients. That is why a fertility preservation strategy should be individualized and tailored distinctively for each patient in order to be effective. Artificial human ovary is a novel experimental in vitro technology to produce mature oocytes that could be the safest option to preserve and restore fertility of young women and girls with hematological malignancies especially when other fertility preservation options are not feasible or contraindicated. Further research and studies are needed to improve the results of artificial human ovary and establish it in clinical practice.

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.

Fertility in adult women with classic galactosemia and primary ovarian insufficiency

OBJECTIVE

To study pregnancy chance in adult women with classic galactosemia and primary ovarian insufficiency. Despite dietary treatment, >90% of women with classic galactosemia develop primary ovarian insufficiency, resulting in impaired fertility. For many years, chance of spontaneous conception has not been considered, leading to counseling for infertility. But an increasing number of reports on pregnancies in this group questions whether current counseling approaches are correct.

DESIGN

Multicenter retrospective observational study.

SETTING

Metabolic centers.

PATIENT(S)

Adult women (aged >18 y) with confirmed classic galactosemia and primary ovarian insufficiency were included.

INTERVENTION(S)

Participants and medical records were consulted to obtain study data in a standardized manner with the use of a questionnaire.

MAIN OUTCOME MEASURE(S)

Conception opportunities, time to pregnancy, pregnancy outcome, hormone replacement therapy use, fertility counseling, and the participants' vision of fertility were evaluated. Potential predictive factors for increased pregnancy chance were explored.

RESULT(S)

Eighty-five women with classic galactosemia and primary ovarian insufficiency participated. Twenty-one women actively attempted to conceive or did not take adequate contraceptive precautions. Of these 21 women, nine became pregnant spontaneously (42.9%). This was higher than reported in primary ovarian insufficiency due to other causes (5%-10%). After a period of 12 months, a cumulative proportion of 27.8% of couples had conceived, which increased to 48.4% after 24 months and 61.3% after 27 months. Predictive factors could not be identified. A considerable miscarriage rate of 30% was observed (6 of 20 pregnancies). Although a substantial proportion of women expressed a child-wish (n = 28/53; 52.8%), the vast majority of participants (n = 43/57; 75.4%) considered conceiving to be highly unlikely, owing to negative counseling in the past.

CONCLUSION(S)

The pregnancy rate in women with classic galactosemia and primary ovarian insufficiency was higher than for women with primary ovarian insufficiency of any cause. This shifting paradigm carries significant implications for fertility counseling and potential application of fertility preservation techniques.

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.

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.

Functional Tissue Analysis Reveals Successful Cryopreservation of Human Osteoarthritic Synovium

Osteoarthritis (OA) is a degenerative joint disease affecting cartilage and is the most common form of arthritis worldwide. One third of OA patients have severe synovitis and less than 10% have no evidence of synovitis. Moreover, synovitis is predictive for more severe disease progression. This offers a target for therapy but more research on the pathophysiological processes in the synovial tissue of these patients is needed. Functional studies performed with synovial tissue will be more approachable when this material, that becomes available by joint replacement surgery, can be stored for later use. We set out to determine the consequences of slow-freezing of human OA synovial tissue. Therefore, we validated a method that can be applied in every routine laboratory and performed a comparative study of five cryoprotective agent (CPA) solutions. To determine possible deleterious cryopreservation-thaw effects on viability, the synovial tissue architecture, metabolic activity, RNA quality, expression of cryopreservation associated stress genes, and expression of OA characteristic disease genes was studied. Furthermore, the biological activity of the cryopreserved tissue was determined by measuring cytokine secretion induced by the TLR ligands lipopolysaccharides and Pam3Cys. Compared to non frozen synovium, no difference in cell and tissue morphology could be identified in the conditions using the CS10, standard and CryoSFM CPA solution for cryopreservation. However, we observed significantly lower preservation of tissue morphology with the Biofreeze and CS2 media. The other viability assays showed trends in the same direction but were not sensitive enough to detect significant differences between conditions. In all assays tested a clearly lower viability was detected in the condition in which synovium was frozen without CPA solution. This detailed analysis showed that OA synovial tissue explants can be cryopreserved while maintaining the morphology, viability and phenotypical response after thawing, offering enhanced opportunities for human in vitro studies.

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.

New advances in ovarian autotransplantation to restore fertility in cancer patients

Human ovary autotransplantation is a promising option for fertility preservation of young women and girls undergoing gonadotoxic treatments for cancer or some autoimmune diseases. Although experimental, it resulted in at least 42 healthy babies worldwide. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature review was performed for all relevant full-text articles published in English from 1 January 2000 to 01 October 2015 in PubMed to explore the latest clinical and research advances of human ovary autotransplantation. Human ovary autotransplantation involves ovarian tissue extraction, freezing/thawing, and transplantation back into the same patient. Three major forms of human ovary autotransplantation exist including (a) transplantation of cortical ovarian tissue, (b) transplantation of whole ovary, and (c) transplantation of ovarian follicles (artificial ovary). According to the recent guidelines, human ovary autotransplantation is still considered experimental; however, it has unique advantages in comparison to other options of female fertility preservation. Human ovary autotransplantation (i) does not need prior ovarian stimulation, (ii) allows immediate initiation of cancer therapy, (iii) can restore both endocrine and reproductive ovarian functions, and (iv) may be the only fertility preservation option suitable for prepubertal girls or for young women with estrogen-sensitive malignancies. As any other fertility preservation option, human ovary autotransplantation has both advantages and disadvantages and may not be feasible for all cases. The major challenges facing this option are how to avoid the risk of reintroducing malignant cells and how to prolong the lifespan of ovarian transplant as well as how to improve artificial ovary results.

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

Primordial follicles dictate a female's reproductive life span and therefore are central to fertility preservation for both endangered species and individuals with fertility-threatening conditions. Ovarian tissue containing primordial follicles can be cryopreserved and later thawed and transplanted back into individuals to restore both endocrine function and fertility. Importantly, increasing numbers of human live births have been reported following ovarian tissue cryopreservation and transplantation. A current limitation of this technology is patient access to sites that are approved or equipped to process and cryopreserve ovarian tissue - especially in larger countries or low resource settings. Here, we review empirical evidence from both animal models and human studies that suggest that ovarian tissue can be transported at cold temperatures for several hours while still maintaining the integrity and reproductive potential of the primordial follicles within the tissue. In fact, several human live births have been reported in European countries using tissue that was transported at cold temperatures for up to 20 h before cryopreservation and transplantation. Ovarian tissue transport, if implemented widely in clinical practice, could therefore expand both patient and provider access to emerging fertility preservation options.

Updates in preserving reproductive potential of prepubertal girls with cancer: Systematic review

INTRODUCTION

With increasing numbers of adult female survivors of childhood cancers due to advances in early diagnosis and treatment, the issue of preserving the reproductive potential of prepubertal girls undergoing gonadotoxic treatments has gained greater attention.

METHODS

According to PRISMA guidelines, a systematic review of the literature was performed for all relevant full-text articles published in PubMed in English throughout the past 15 years to explore the significant updates in preserving the reproductive potential of prepubertal girls with cancer.

RESULTS

The two established fertility preservation options, embryo freezing and egg freezing, cannot be offered routinely to prepubertal girls as these options necessitate prior ovarian stimulation and subsequent mature oocytes retrieval that are contraindicated or infeasible before puberty. Therefore, the most suitable fertility preservation options to prepubertal girls are (1) ovarian tissue freezing and autotransplantation, (2) in vitro maturation, and (3) ovarian protection techniques. In this review, we discuss in detail those options as well as their success rates, advantages, disadvantages and future directions. We also suggest a new integrated strategy to preserve the reproductive potential of prepubertal girls with cancer.

CONCLUSION

Although experimental, ovarian tissue slow freezing and orthotopic autotransplantation may be the most feasible option to preserve the reproductive potential of prepubertal girls with cancer. However, this technique has two major and serious disadvantages: (1) the risk of reintroducing malignant cells, and (2) the relatively short lifespan of ovarian tissue transplants. Several medical and ethical considerations should be taken into account before applying this technique to prepubertal girls with cancer.

Fertility Preservation Options for Men and Women With Cancer

Approximately 0.2% of Americans aged 20 to 39 years are childhood cancer survivors. Advances in cancer detection and therapy have greatly improved survival rates for young cancer patients; however, treatment of childhood cancers can adversely impact reproductive function. Many cancer patients report a strong desire to be informed of existing options for fertility preservation and future reproduction prior to initiation of gonadotoxic cancer therapies, including surgery, chemotherapy, and radiotherapy. This article discusses, in detail, the effects of cancer treatment on fertility in men and women, and outlines both current and experimental methods of fertility preservation among cancer patients.