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

Evaluation of the effect of human testicular cell conditioned media on the in vitro development of follicles from cryopreserved human ovarian cortical pieces. A potential approach for fertility preservation for cancer patients

If in vitro culture conditions could be improved, in vitro growth of cryopreserved ovarian tissue and isolated follicles could become an alternative to ovarian tissue transplantation. This study evaluated two cryopreservation methods, slow cooling and vitrification, and two in vitro culture methods, to determine their effect on the in vitro growth of human ovarian follicles. After warming, the OT pieces (1 × 10 × 3 mm) were cultured in either routine culture medium (DMEM), or DMEM supplemented 50:50 with media previously used for human testicular cell culture (hTCCM) to serve as a source of growth factors. Several parameters were evaluated during culture including follicle recruitment, growth, morphology, diameter, hormone production, and gene expressions (PTEN, BMP-15, PDGF, GDF-9, and GAPDH). The follicular morphology and hormonal secretion were comparable for both cryopreservation methods and both culture methods (P > 0.05). Follicle recruitment was accelerated in the vitrified group, in the presence of hTCCM (P > 0.05). After 7 days of culture, the follicle diameter was greater in the slow/hTCCM compared to the vitrification DMEM group. Similarly only one gene expression profile, BMP-15, in the slow/hTCCM differed significantly from another treatment group (Vit DMEM). At the end of culture (over 21 days), three immature, low-quality oocytes were the achievement. In conclusion, a very quick and easy vitrification protocol gave comparable results to the slow cooling method. We also established that the laboriously prepared hTCCM supplement did not benefit the outcomes. Further work is needed before in vitro maturation of cryopreserved ovarian cortical pieces can be used clinically.

Laboratory practice in an oncology cryopreservation service: What and how?

In humans, oocyte and embryo vitrification is a routinely used method for fertility preservation (FP). Sperm vitrification is currently applied to samples with low sperm concentration and volume, whereas slow freezing remains the preferred method for larger sperm volumes. Although ovarian tissue cryopreservation and testicular tissue cryopreservation are not yet routinely used for FP, the cryopreservation methods are a matter of debate. Slow freezing is the most commonly applied method for the ovarian cortex, while ovarian tissue vitrification remains clinically uncertain due to the limited number of successful births. It is important to underline that the guidelines for gametes, embryos, and tissue cryopreservation have a key role for both providers and patients, which is to minimize the risks associated with an unsafe FP choice and cryostorage.

Optimization of freezing and thawing protocols for human ovarian tissue cryopreservation through thermophysical characterisation of freezing medium by differential scanning calorimetry

Fertility preservation should be offered to patients facing gonadotoxic therapy. The method for preserving prepubescent girls' fertility, which is also suitable for women, is ovarian tissue cryopreservation (OTC). Although 200 births have been reported worldwide with this approach, significant improvements are needed. The literature indeed reports numerous protocols for freezing and thawing ovarian tissue, with no clear rationale for selection criteria. This study aims to optimize human OTC protocols by characterizing the thermodynamic properties of freezing medium. The freezing medium associated with most live births after autograft (Leibovitz L-15 medium with 4 mg/mL human serum albumin (HSA), 1.5M DMSO, and 0.1M sucrose) was characterized using differential scanning calorimetry. We obtained -120.49 °C for glass transition temperature (Tg'), -20 °C for crystallization temperature when cooling at 2.5 °C/min (Tc) and -4.11 °C for melting temperature (Tm). With these parameters, we optimized a freezing protocol in a programmable freezer (Nano-Digitcool, Cryo Bio System) and a thawing protocol. The freezing curve was as follows: 5 min at 4 °C, 1 °C/min to -7 °C, seeding: 60 °C/min to -32 °C, and 10 °C/min to -15 °C, 0.3 °C/min to -40 °C, 10 °C/min to -140 °C. The thawing protocol consisted in a 3.5-min step in a cold chamber to reach slowly Tg', limiting thermal and mechanical shocks, and then a 2-min incubation at 37 °C to quickly reach Tm. Ovarian tissue frozen-thawed according to these protocols had a similar quality to that of fresh tissue and could resume folliculogenesis during organotypic culture. Our study will contribute to improve human OTC and optimize women fertility preservation.

Age- and sex-specific reference intervals for anti-Müllerian hormone during childhood in Chinese population: a cross-sectional study of 2,450 healthy children

Background

Anti-Müllerian hormone (AMH) serves as a reliable biomarker of testicular function in males and ovarian function in females. However, reference intervals (RIs) for AMH in Chinese pediatric populations are scarce. This study aimed to establish age- and sex-specific RIs for AMH in healthy Chinese children and explore its correlation with six sex hormones.

Methods

A cross-sectional study conducted from September 2022 to August 2023 recruited 2,450 healthy participants aged 1 day-19 years. Serum AMH levels were measured using the CL-6000i automated chemiluminescence immunoassay analyzer (Mindray, Shenzhen, China). RIs were established following Clinical and Laboratory Standards Institute (CLSI) guidelines and were defined according to the nonparametric median (P50), the 2.5th (P2.5) and 97.5th (P97.5) percentiles and 95% interval range (P2.5-P97.5).

Results

In males, serum AMH levels were high at birth [1 d-1 m: 46.49 (2.89, 120.15) ng/mL], increased markedly from 1 to 12 months [94.75 (0.49, 248.73) ng/mL], and then continuously declined until 18 years of age [15-18 years: 5.33 (0.83, 13.72) ng/mL)], followed by a slight increase between 18 and 19 years of age [6.79 (2.22, 17.32) ng/mL]. In females, serum AMH levels were low within the first month after birth [0.27 (0.01, 88.7) ng/mL], gradually increased thereafter, peaked at 9 years of age [1 m-9 y: 2.32 (0.45, 103.99) ng/mL], underwent a slight decline between 9 and 15 years [2.49 (0.51, 60.00) ng/mL], and reached a plateau from 15 to 19 years [3.44 (1.13, 10.32) ng/mL]. Age- and sex-specific RIs for AMH were determined. There were four age-specific RIs in males including 1 day-1 month (P50 46.49 ng/mL; 95% interval range, 2.89-120.15 ng/mL), >1 month-3 years (P50 92.20 ng/mL; 95% interval range, 1.05-232.77 ng/mL), >3-12 years (P50 44.97 ng/mL; 95% interval range, 1.50-121.97 ng/mL), and >12-19 years (P50 6.23 ng/mL; 95% interval range, 1.94-16.14 ng/mL). Similarly, there were four age-specific RIs in females, including1 day-1 month (P50 0.27 ng/mL; 95% interval range, 0.01-88.7 ng/mL), >1 month-9 years (P50 2.32 ng/mL; 95% interval range, 0.45-103.99 ng/mL), >9-15 years (P50 2.49 ng/mL; 95% interval range, 0.51-60.00 ng/mL), and >15-19 years (P50 3.44 ng/mL; 95% interval range, 1.13-10.32 ng/mL).

Conclusions

In this study, we established age- and sex-specific serum AMH RIs using the Mindray CL-6000i system in healthy children in Wuhan, China. AMH exhibits significant fluctuations across the various stages of growth and development in both genders. This will aid in providing clinicians with a decision-making tool and broaden its application in pediatric care.

Ovarian tissue cryopreservation for fertility preservation: a two-decade single-center experience with 451 children and adolescents

BACKGROUND

Ovarian tissue cryopreservation (OTC) is the only fertility preservation option for premenarcheal girls before gonadotoxic treatment, but is still considered to be experimental in pediatric patients. This study investigated storage behaviors across different age groups to refine counseling approaches for pediatric patients.

METHODS

This retrospective study analyzed data from children (0-14 years), adolescents (15-19 years), and adults (≥ 20 years) who underwent OTC between 2000-2021 at the University Hospital Bonn's cryobank. Comparison to adults (age ≥ 20 years) was conducted.

RESULTS

Of 2,475 patients, 6% were children and 12% adolescents. Sarcoma was most common in children, lymphoma in adolescents. Adults had longer active storage than children (5.5 vs. 4.7 years, p = 0.011), but for active storage ≥ 10 years, children and adolescents stored longer than adults (13.1 and 12.6 vs. 11.8 years, p ≤ 0.01). The proportion of adolescents increased, while that of children decreased in long-term storage. Median ovarian cortex surface before cryopreservation was 3.5 cm2 in children and 4.5 cm2 in adolescents. Leukemia and sarcoma had the highest mortality rates in children (25% and 13.5%). Overall, pregnancy and birth rates following ovarian tissue transplantation (OTT) were 34.5% and 24.1%, respectively. Among adolescents, pregnancy rates were 33.3% after OTT and 27.3% without OTT, while all children without OTT achieved pregnancy (100%).

CONCLUSIONS

Children and adolescents represent a small subset of OTC patients, with indications linked to common pediatric malignancies. For active storage ≥ 10 years, they store longer than adults, likely due to delayed reproduction or awaiting in vitro growth / in vitro maturation in hematological cases. Overall, adults store longer, but adolescent storage has risen over time possibly due to higher child mortality and previously limited OTC use in younger patients. Mean ovarian cortex surface data may guide pediatric tissue harvest recommendations, with unilateral oophorectomy advised. Fertility preservation counseling and cost coverage should be standard for pediatric patients undergoing gonadotoxic treatment. A tailored approach to OTC indications is essential, especially in high-mortality cancers like leukemia or sarcoma. Favorable pregnancy rates observed, even without OTT, suggest possible OTC overutilization, highlighting the need for individualized strategies and careful clinical decision-making to balance risks and preserve reproductive potential.

Comparison of the quality of ovarian tissue cryopreservation by conventional slow cryopreservation and vitrification-a systematic review and meta-analysis

BACKGROUND

Ovarian tissue cryopreservation is increasingly applied in patients undergoing gonadotoxic radiotherapy or chemotherapy treatment or other patients who need to preserve their fertility. However, there is currently limited evidence to know which type of ovarian tissue cryopreservation is better. The advantages and disadvantages of conventional slow cryopreservation and vitrification are still controversial. The purpose of this meta-analysis was to analyze the ovarian tissue quality of ovarian tissue cryopreservation by conventional slow cryopreservation and vitrification.

METHODS

According to the keywords, Pubmed, Embase, and Cochrane Library were searched for studies to January 2024. Studies comparing the follicular viability of conventional slow cryopreservation versus vitrification were assessed for eligibility. The meta-analysis was performed using Stata software (Version 12.0) and Review Manager (Version 5.2).

RESULTS

A total of 18 studies were included in this meta-analysis. The pooled results of the primary outcomes indicated that there was no difference between the two approaches for follicular viability (RR = 0.96, 95% CI: 0.84-1.09, P = 0.520, I2 = 95.8%, Random-effect), the proportion of intact primordial follicles (RR = 1.01, 95% CI: 0.94-1.09, P = 0.778, I2 = 70.6%, Random-effect). The pooled results of the secondary outcomes indicated that there was no difference between the two approaches for the proportion of DNA fragmented follicles (RR = 1.20, 95% CI: 0.94-1.54, P = 0.151, I2 = 0.0%, Fixed-effect), and the proportion of stromal cells (RR = 0.58, 95% CI: 0.20-1.65, P = 0.303, I2 = 99.7%, Random-effect).

CONCLUSIONS

Conventional slow cryopreservation and vitrification appear to provide comparable outcomes. The heterogeneity of the literature prevents us from comparing these two techniques. Further high-quality studies are needed to enhance this statement. This meta-analysis provides limited data which may help clinicians when counselling patients.

The first comparative study on the effectiveness of slow freezing and vitrification of human ovarian tissue by xenotransplantation model in Vietnam

PURPOSE

To compare the effectiveness of slow freezing (SF) and vitrification (VT) for ovarian tissue cryopreservation using a xenograft model.

METHODS

From September 2020 to August 2023, ovarian tissues from patients aged 18 to 37 undergoing benign ovarian surgery were divided into three groups. Group 1: fresh tissues (FC) were immediately fixed for analysis. Group 2 (SF/VT): tissues were cryopreserved by SF or VT without transplantation. Group 3 (SF-T/VT-T): tissues were cryopreserved using SF or VT, followed by transplantation into NOD-SCID mice for one week, after which the tissues were collected and analyzed.

RESULTS

A total of 49 ovarian tissue fragments were analyzed. Regardless of the cryopreservation technique, follicle survival, development, function, and vascularization were significantly reduced compared to the FC group, particularly after transplantation (p < 0.001). The survival rate of follicles in the SF-T group was notably higher (90.9%) than in the VT-T group (82.6%) (p < 0.001). For cell proliferation, indicated by Ki-67 positivity, the SF-T group showed a higher median number of positive follicles (2.5; range: 0-18) compared to the VT-T group (2; range: 0-11) (p = 0.04). Neo-vascularization, assessed via CD31 positivity, was significantly greater in the SF-T group (61%) than in the VT-T group (47%) (p = 0.016). Additionally, the median number of AMH-positive follicles was significantly higher in the SF-T group (3; range: 0-23) compared to the VT-T group (2; range: 0-25) (p = 0.03).

CONCLUSION

Both SF and VT are feasible methods for ovarian tissue cryopreservation. SF may be the preferred cryopreservation technique for fertility preservation in cases tissue transplantation is anticipated.

Clinical and ethical perspectives of ovarian stimulation and oocyte cryopreservation in adolescents: 6 years experience from a tertiary centre

STUDY QUESTION

What are the clinical and ethical challenges of performing ovarian stimulation and oocyte cryopreservation in adolescents and the barriers to providing treatment?

SUMMARY ANSWER

Our study shows that, in one of the largest case series to date in this population, post-pubertal adolescents as young as age 13 years can undergo ovarian stimulation and oocyte cryopreservation with a response comparable to adults.

WHAT IS KNOWN ALREADY

Fertility preservation in adolescents has not been well studied, with little data available in the existing literature. Referrals for fertility preservation in adolescents are increasing due to developments in childhood cancer treatments, which have led to a growing population of children at risk of developing premature ovarian insufficiency. Those with certain benign conditions or gender incongruence also face this challenge. All established fertility preservation guidelines state that where there is a risk to fertility, oocyte cryopreservation should be offered to post-pubertal females. However, counselling and consenting young people about fertility decisions is an ethically complex area, and assessing capacity to consent in this age group is not straightforward.

STUDY DESIGN SIZE DURATION

This was a retrospective observational cohort study of 182 referrals for fertility preservation counselling to a specialist unit, and we present outcomes for the 33 adolescents who underwent 36 cycles of ovarian stimulation and oocyte cryopreservation between January 2018 and January 2024.

PARTICIPANTS/MATERIALS SETTING METHODS

We included patients aged 13-18 years who underwent ovarian stimulation and oocyte cryopreservation for fertility preservation due to high or intermediate risk of gonadotoxicity from medical or surgical treatment at a public-funded specialist unit. The primary outcome was oocyte yield; secondary outcomes included oocyte maturity rate, complications, and dropout rate. Data were retrieved from a prospectively managed database.

MAIN RESULTS AND THE ROLE OF CHANCE

There was a total of 182 referrals received, and of these, 33 patients underwent 36 cycles of ovarian stimulation and oocyte cryopreservation. Indications for fertility preservation included malignancy n = 19/36 (54%), ovarian cyst surgery n = 7/36 (19%), immunological disorders n = 4/36 (11%), benign haematological disease n = 2/36 (6%), gender reassignment treatment n = 3/36 (8%), and genetic conditions n = 1/36 (3%). The youngest child who underwent ovarian stimulation was aged 13 years and 10 months at the time of egg collection; the minimum time from menarche to ovarian stimulation was 4 months, the median AMH (anti-Müllerian hormone) was 16.7 pmol/l (range 2.8-36.9 pmol/l), and the antral follicle count (AFC) was 11 (3-36). The median number of cryopreserved oocytes was 14 (range 4-39), and the oocyte maturity rate was 85% (35-100%). Ultrasound monitoring was performed transabdominally in 5/33 (15%) and transvaginally in 28/33 (85%). Egg collection was performed transvaginally in all cases in this cohort. All cycles proceeded to completion. All adolescents were counselled in association with a family member to obtain informed consent, and all were assessed as able to comprehend discussions.

LIMITATIONS REASONS FOR CAUTION

In view of concerns regarding increased aneuploidy rates in this age group compared to women in their twenties, there is a need for long-term outcome studies expanding on our findings with data on livebirths to support clinicians needing to counsel patients and perform oocyte cryopreservation in adolescents.

WIDER IMPLICATIONS OF THE FINDINGS

Clinician experience, correct setting, and availability of funding will enable a permissive environment for oocyte cryopreservation in adolescents. In our experience, transvaginal egg collection is an accepted procedure when counselled appropriately.

STUDY FUNDING/COMPETING INTERESTS

No funding was received for this work. No competing interests are declared.

TRIAL REGISTRATION NUMBER

N/A.

First successful ovarian cortex allotransplant to a Turner syndrome patient requiring immunosuppression: wide implications

OBJECTIVE

To determine whether we can safely and successfully transplant an ovary tissue allograft from a nonidentical donor to her Turner syndrome sister.

DESIGN

Transplantation of cryopreserved ovary tissue, as well as fresh transplantation of ovarian tissue between identical twins, is now well established with numerous reported successful cases. However, there have not yet been any ovary transplants between nonidentical women requiring immunosuppression (ovary allotransplant). This could be a much more common indication for ovary tissue transplantation if safe and reliable immunosuppression were available.

PATIENT(S)

A 20-year-old amenorrheic woman with nonmosaic 45-XO Turner syndrome requested ovary tissue transplantation from her fertile 22-year-old 46-XX sister. They were an human leukocyte antigens match but were ABO incompatible, a well-known contra-indication to solid tissue or organ transplantation. The Turner syndrome sister strongly preferred to be able to become pregnant naturally without donor egg in vitro fertilization and to avoid hormone replacement therapy. In her religious group, that would also be important for finding a marital match. Despite the poor prognosis associated with ABO incompatibility, an ovary from her 22-year-old nonidentical fertile sister was transplanted to her employing the immunosuppression protocol now used for kidney transplant patients in our centers at Washington University and Johns Hopkins.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Post operatively at 5 months she developed normal monthly menstrual ovarian function, and she became spontaneously pregnant with a normal infant girl. The relation between her postoperation follicle stimulating hormone and antimüllerian hormone levels continue to support the theory that tissue pressure controls primordial follicle recruitment. The fact that ABO incompatibility did not prevent success suggests that diffusion and not revascularization may be all that is required for successful long-term ovarian cortex transplant survival with spontaneous pregnancy.

RESULT(S)

Ovary allotransplantation with safe immunosuppression allows natural conception, and also normal hormone function obviates the need for hormone replacement therapy. Orthotopic placement of the graft and surgical technique is critical for natural conception and a higher pregnancy rate.

CONCLUSION(S)

Allotransplantation requiring safe immunosuppression, if successful, maybe a much more commonly used indication for ovary transplantation in the future than frozen ovary grafts or grafts between identical twins.

Comparative effectiveness of vitrification and slow freezing after heterotopic transplantation of human ovarian tissues

BACKGROUND

The aim of this study was to compare the effectiveness of two different vitrification methods and slow freezing in terms of the recovery of endocrine function, follicular morphology and proliferation, apoptosis of stromal cells, and angiogenesis after heterotopic transplantation of human ovarian tissue.

METHODS

Ovarian tissue from young women aged 29 to 40 was subjected to two vitrification methods and one slow freezing method. The thawed ovarian tissue was then transplanted into nude mice and divided into three groups (VF1 group, VF2 group, SF group) according to the different freezing methods. Ovarian tissue samples were collected at 4 and 6 weeks post-transplantation. The recovery of ovarian function was evaluated by observing the estrous cycle and measuring estradiol levels using Elisa. Histological evaluation was performed to assess the integrity of ovarian follicles. TUNEL assay was used to detect stromal cell apoptosis, and immunohistochemistry was conducted to evaluate follicular proliferation and tissue angiogenesis.

RESULTS

After heterotopic transplantation, mice in the experimental groups exhibited restoration of the estrous cycle. Hormone levels showed an increasing trend in the vitrification groups. At 6 weeks post-transplantation, the VF2 group had significantly higher hormone levels compared to the VF1 group and the slow freezing (SF) group (P < 0.05). At 4 weeks post-transplantation, the proportion of normal follicles was higher in the VF2 group compared to the other two groups (P > 0.05), and at 6 weeks post-transplantation, the VF2 group was significantly higher than the SF group (P < 0.05) and slightly higher than the VF1 group. Immunohistochemistry analysis indicated a higher proportion of proliferating follicles in the vitrification groups compared to the slow freezing group (P > 0.05). CD31 expression was established in all groups at 4 and 6 weeks post-transplantation, with better results in the slow freezing group compared to the vitrification group. TUNEL analysis showed that stromal cell apoptosis was higher in the SF group compared to the vitrification group at 4 weeks post-transplantation (P < 0.05), while there was no significant statistical difference among the groups at 6 weeks post-transplantation.

CONCLUSIONS

Vitrification showed better results than slow freezing, with the VF2 group performing slightly better than the VF1 group. Considering the lower economic and time costs associated with vitrification, it may be more suitable for ovarian tissue cryopreservation in major research centers in the future.

Disparities in access to fertility preservation among adolescents undergoing gonadotoxic therapies

PURPOSE

Fertility preservation (FP) for adolescents prior to potentially gonadotoxic therapies is not accessible for all patients. Current literature acknowledges multiple barriers to FP, but research surrounding disparities for accessing these services is limited. We aimed to identify inequities in receiving FP services among adolescents undergoing gonadotoxic therapy.

METHODS

A retrospective chart review was performed at a single academic medical center for patients aged 0-21 referred for FP counseling prior to gonadotoxic therapy. Exclusions included referral after treatment, prior to gender-affirming therapy, or for fertility discussion due to a genetic condition. Minority patients were defined as non-White race and/or Hispanic ethnicity. Non-minority patients were defined as White, non-Hispanic. Analyses to assess differences in receiving FP based on minority identity and insurance status were performed via logistic regression, with receiving desired care as the outcome variable.

RESULTS

Our cohort included 136 patients-38 minority and 98 non-minority. Forty-six (33.8%) patients had Medicaid, which did not differ between minority and non-minority (42.1% vs. 38.8%, P = .73). Most patients (83.1%) had a cancer diagnosis. Similar proportions of minority and non-minority patients had gonadotoxic treatment starting urgently (52.6% vs. 55.1%, P = .80), while more minority than non-minority patients desired FP (89.5% vs .77.5%, P = .10). When controlling for insurance type and age, minority participants were 12.8% less likely to receive desired FP (marginal effect =  - .128, P = .05).

CONCLUSIONS

This study identified significant inequities for minority populations in accessing FP. Further research is needed to determine how to make FP services more accessible to all patients, regardless of minority status.

Oncofertility in Children and Adolescents

Major improvements have been seen in oncofertility care over the last decade. Clinical ethics frameworks support new populations, including children, having access to novel fertility preservation techniques. Oncofertility consultation requires a multidisciplinary approach. Clinicians need to develop competencies in infertility risk-assessment, counseling regarding fertility preservation procedures and alternate family planning options, and managing individualised supportive care needs to minimize medical and psychological morbidity.

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.

Ovarian tissue cryopreservation and transplantation as a natural means to delay menopause

Ovarian tissue cryopreservation and transplantation (OTCT) offers hope for preserving fertility and endocrine functions in patients undergoing gonadotoxic treatments. Advancements in techniques for the procedure have transformed OTCT from an experimental procedure into a viable option. There is a growing interest in utilizing OTCT to delay menopause and alleviate associated health issues. Menopausal transition affects women globally, leading to symptoms and long- term health risks. OTCT has the potential to restore endocrine functions, reducing menopause-related symptoms while mitigating health consequences such as osteoporosis and cardiovascular diseases. Although the use of OTCT for delaying menopause is not clinically proven, the discussion around shows potential for future utilization. In essence, the remarkable advancements in OTCT have bestowed upon us the ability to safeguard fertility and sustain the delicate endocrine functions of the ovaries. However, it is the tantalizing prospect of utilizing this technique to postpone menopause and alleviate its associated symptoms that truly captivates the imagination. Further research is imperative to substantiate the clinical efficacy of OTCT; nonetheless, its potential in menopausal therapy is both promising and warrants comprehensive exploration. This review highlights advancements and the feasibility of OTCT to postpone menopause as an alternative approach to currently used conventional menopause therapy methods.

Current State and Challenges of Tissue and Organ Cryopreservation in Biobanking

Recent years have witnessed significant advancements in the cryopreservation of various tissues and cells, yet several challenges persist. This review evaluates the current state of cryopreservation, focusing on contemporary methods, notable achievements, and ongoing difficulties. Techniques such as slow freezing and vitrification have enabled the successful preservation of diverse biological materials, including embryos and ovarian tissue, marking substantial progress in reproductive medicine and regenerative therapies. These achievements highlight improved post-thaw survival and functionality of cryopreserved samples. However, there are remaining challenges such as ice crystal formation, which can lead to cell damage, and the cryopreservation of larger, more complex tissues and organs. This review also explores the role of cryoprotectants and the importance of optimizing both cooling and warming rates to enhance preservation outcomes. Future research priorities include developing new cryoprotective agents, elucidating the mechanisms of cryoinjury, and refining protocols for preserving complex tissues and organs. This comprehensive overview underscores the transformative potential of cryopreservation in biomedicine, while emphasizing the necessity for ongoing innovation to address existing challenges.

Thawing fertility: a view of ovarian tissue cryopreservation processes and review of ovarian transplant research

Individuals with a disease or treatment that increases their risk of premature gonadal insufficiency may opt to undergo fertility preservation. Those who are postpubertal can often cryopreserve gametes, sperm, or eggs to expand their biologic family using assisted reproductive technologies. Ovarian tissue cryopreservation (OTC) and testicular tissue cryopreservation may be an option for individuals who are unable to use standard fertility preservation techniques. The development of OTC was critical for many patients, including prepubertal children with ovaries that do not yet produce eggs, adolescents who make few good-quality eggs, and adult women with ovaries who cannot undergo ovarian stimulation. The only option to restore fertility and hormone production after OTC is through ovarian tissue transplantation (OTT). Ovarian tissue cryopreservation and OTT have been successful for some patients. Although OTC is no longer considered experimental by the American Society for Reproductive Medicine, the process is far from standardized. Significant research needs to be done, especially at the point of OTT, to improve the success and longevity of ovarian tissue function. This article lists the main steps from surgical procurement of the ovarian tissue to transplantation and restoration of function. Our pediatric hospital program has had to decide which options in procurement, processing, cryopreservation, and warming will be used in our clinical laboratory. The options and limitations within the research and analyses are briefly discussed. Literature focusing on techniques to improve OTT effectiveness and longevity was reviewed. Ovarian tissue transplantation studies that performed xenograft experiments after pretreatment of the tissue graft by a ligand or drug, treatment of the host, or encapsulation of the ovarian tissue were identified. The intended effects of the treatments include increasing vascularization, reducing apoptosis, and directing activation or suppression of primordial follicles. Robust research in this area must continue with rigorous analyses to make strides in improving fertility preservation and restoration options for patients.

Exploring the Frontiers of Ovarian Tissue Cryopreservation: A Review

Objective: This paper serves as an up-to-date narrative review of the most effective methods and outcomes of ovarian tissue cryopreservation (OTC) with new data comparing this method to oocyte and embryo cryopreservation as well as its utility in restoration of endocrine function. Background: Data on OTC are becoming more available as more patients are achieving cancer remission and choosing to use their cryopreserved tissue to conceive or restore endocrine function. With OTC only recently becoming a non-experimental method of fertility preservation, it is important to evaluate, compare, and optimize current practices to improve live birth outcomes. Methods: A literature search of meta-analyses, systematic reviews, case series, retrospective studies, and randomized control trials was performed using the PubMed database with multiple search terms. Discussion: Current practices and outcomes of OTC remain heterogeneous, though they are becoming more streamlined with the emerging data on successful live births. Multiple aspects of OTC have been studied to optimize protocols, particularly methods of cryopreserving, in vitro maturation, and transplantation. In vitro follicle maturation is a novel application with emerging data on methods and outcomes. OTC is a versatile method not only for fertility preservation but also for hormone restoration as well. With wider usage of OTC, ethical dilemmas will need to be addressed. Conclusions: OTC can be used as fertility preservation for a variety of patients. Recent studies suggest it may be comparable to embryo cryopreservation, but with growing data on live births, comparative studies should continue to be performed. In vitro follicle maturation (IVFM) is a promising application of ovarian tissue harvesting. Data are lacking on cost-effectiveness, patient satisfaction, and morbidity associated with OTC.

The Shared Ovary: A Multidisciplinary Discussion With Pediatric and Adolescent Gynecology

Pediatric and adolescent ovarian lesions are common and are frequently managed by both pediatric surgeons and pediatric and adolescent gynecologists. During the 2023 American Academy of Pediatric Section on Surgery meeting, an educational symposium was delivered focusing on various aspects of management of pediatric and adolescent benign and malignant masses, borderline lesions, and fertility options for children and adolescents undergoing cancer therapies. This article highlights the discussion during this symposium.

Quantification of follicles in human ovarian tissue using image processing software and trained artificial intelligence†

Cancer survival rates in prepubertal girls and young women have risen in recent decades due to increasingly efficient treatments. However, many such treatments are gonadotoxic, causing premature ovarian insufficiency, loss of fertility, and ovarian endocrine function. Implantation of donor ovarian tissue encapsulated in immune-isolating capsules is a promising method to restore physiological endocrine function without immunosuppression or risk of reintroducing cancer cells harbored by the tissue. The success of this approach is largely determined by follicle density in the implanted ovarian tissue, which is analyzed manually from histologic sections and necessitates specialized, time-consuming labor. To address this limitation, we developed a fully automated method to quantify follicle density that does not require additional coding. We first analyzed ovarian tissue from 12 human donors between 16 and 37 years old using semi-automated image processing with manual follicle annotation and then trained artificial intelligence program based on follicle identification and object classification. One operator manually analyzed 102 whole slide images from serial histologic sections. Of those, 77 images were assessed by a second manual operator, followed with an automated method utilizing artificial intelligence. Of the 1181 follicles the control operator counted, the comparison operator counted 1178, and the artificial intelligence counted 927 follicles with 80% of those being correctly identified as follicles. The three-stage artificial intelligence pipeline finished 33% faster than manual annotation. Collectively, this report supports the use of artificial intelligence and automation to select tissue donors and grafts with the greatest follicle density to ensure graft longevity for premature ovarian insufficiency treatment.

In Vitro Maturation, In Vitro Oogenesis, and Ovarian Longevity

This paper will review a remarkable new approach to in vitro maturation "IVM" of oocytes from ovarian tissue, based on our results with in vitro oogenesis from somatic cells. As an aside benefit we also have derived a better understanding of ovarian longevity from ovary transplant. We have found that primordial follicle recruitment is triggered by tissue pressure gradients. Increased pressure holds the follicle in meiotic arrest and prevents recruitment. Therefore recruitment occurs first in the least dense inner tissue of the cortico-medullary junction. Many oocytes can be obtained from human ovarian tissue and mature to metaphase 2 in vitro with no need for ovarian stimulation. Ovarian stimulation may only be necessary for removing the oocyte from the ovary, but this can also be accomplished by simple dissection at the time of ovary tissue cryopreservation. By using surgical dissection of the removed ovary, rather than a needle stick, we can obtain many oocytes from very small follicles not visible with ultrasound. A clearer understanding of ovarian function has come from in vitro oogenesis experiments, and that explains why IVM has now become so simple and robust. Tissue pressure (and just a few "core genes" in the mouse) direct primordial follicle recruitment and development to mature oocyte, and therefore also control ovarian longevity. There are three distinct phases to oocyte development both in vitro and in vivo: in vitro differentiation "IVD" which is not gonadotropin sensitive (the longest phase), in vitro gonadotropin sensitivity "IVG" which is the phase of gonadotropin stimulation to prepare for meiotic competence, and IVM to metaphase II. On any given day 35% of GVs in ovarian tissue have already undergone "IVD" and "IVG" in vivo, and therefore are ready for IVM.

Restoring Ovarian Fertility and Hormone Function: Recent Advancements, Ongoing Efforts and Future Applications

The last 20 years have seen substantial improvements in fertility and hormone preservation and restoration technologies for a growing number of cancer survivors. However, further advancements are required to fill the gaps for those who cannot use current technologies or to improve the efficacy and longevity of current fertility and hormone restoration technologies. Ovarian tissue cryopreservation (OTC) followed by ovarian tissue transplantation (OTT) offers those unable to undergo ovarian stimulation for egg retrieval and cryopreservation an option that restores both fertility and hormone function. However, those with metastatic disease in their ovaries are unable to transplant this tissue. Therefore, new technologies to produce good-quality eggs and restore long-term cyclic ovarian function are being investigated and developed to expand options for a variety of patients. This mini-review describes current and near future technologies including in vitro maturation, in vitro follicle growth and maturation, bioprosthetic ovaries, and stem cell applications in fertility restoration research by their proximity to clinical application.

Investigating the impact of vitrification on bovine ovarian tissue morphology, follicle survival, and transcriptomic signature

PURPOSE

Ovarian tissue cryopreservation is vital for fertility preservation, yet its effect on ovarian tissue follicle survival and transcriptomic signature requires further investigation. This study delves into the effects of vitrification on tissue morphology, function, and transcriptomic changes, helping to find possibilities for vitrification protocol improvements.

METHODS

Ovarian cortex from 19 bovine animals were used to conduct pre- and post-vitrification culture followed by histological assessment, immunohistochemistry, and TUNEL assay. Follicles' functionality was assessed for viability and growth within the tissue and in isolated cultures. RNA-sequencing of ovarian tissue was used to explore the transcriptomic alterations caused by vitrification.

RESULTS

Follicle density, cell proliferation, and DNA damage in ovarian stroma were unaffected by vitrification. However, vitrified cultured tissue exhibited reduced follicle density of primordial/primary and antral follicles, while freshly cultured tissue manifested reduction of antral follicles. Increased stromal cell proliferation and DNA damage occurred in both groups post-culture. Isolated follicles from vitrified tissue exhibited similar viability to fresh follicles until day 4, after which the survival dropped. RNA-sequencing revealed minor effects of vitrification on transcriptomic signatures, while culture induced significant gene expression changes in both groups. The altered expression of WNT and hormonal regulation pathway genes post-vitrification suggests the molecular targets for vitrification protocol refinement.

CONCLUSION

Vitrification minimally affects tissue morphology, follicle density, and transcriptomic signature post-thawing. However, culture revealed notable changes in vitrified tissue samples, including reduced follicle density, decreased isolated follicle survival, and alteration in WNT signalling and ovarian hormonal regulation pathways, highlighted them as possible limitations of the current vitrification protocol.

Successful pregnancy rates amongst patients undergoing ovarian tissue cryopreservation for non-malignant indications: A systematic review and meta-analysis

BACKGROUND

Ovarian tissue cryopreservation (OTC) is a fertility preservation method that has been clinically applied for almost 30 years. Studies specifically evaluating patients presenting with non-malignant indications for OTC and their subsequent pregnancy rates are limited.

OBJECTIVE

To summarise the evidence on the rates of successful pregnancy amongst women who have undergone OTC for non-malignant indications.

METHODS

A systematic review with meta-analysis (PROSPERO registration CRD42022307925) was conducted to investigate the pregnancy outcomes of patients who have undergone ovarian tissue cryopreservation for non-malignant indications. Articles published in EMBASE and Ovid MEDLINE before October 2022 were screened for inclusion based on the following criteria: original human studies pertaining to OTC with a defined non-malignant cohort and pregnancy outcomes. The successful pregnancy rates were pooled with a random-effects model of double-arcsine transformed proportions. Sensitivity analysis involved pooling the results of studies with a low risk of bias after being assessed with NIH tools.

RESULTS

The database search retrieved 3,225 results, of which 16 were included in the meta-analysis. The pooled successful pregnancy rate was 23.52 % (16 studies, 95 % CI 6.48 to 44.79 %). When subgroup analysis of study types was performed, the successful pregnancy rate was higher amongst case series (47.02 %, 9 studies, 95 % CI 6.98 to 89.00 %) than cohort studies (14.64 %, 7 studies, 95 % CI 3.59 to 29.78 %). Sensitivity analysis limited to studies at low risk of bias revealed a similar pooled successful pregnancy rate of 23.35 % (12 studies, 95 % CI 2.50 to 51.96 %).

CONCLUSIONS

Approximately one quarter of women who underwent OTC for non-malignant indications had a successful pregnancy. These findings are clinically important for fertility preservation counselling by providing greater evidence for more informed care.

Safety of ovarian cryopreservation and transplantation in patients with acute leukemia: a case series

BACKGROUND

With increased success, ovarian tissue cryopreservation has recently become a standard technique for fertility preservation. However, malignant cell introduction through ovarian tissue transplantation remains a major concern for patients with acute leukemias.

OBJECTIVE

This study aimed to investigate the safety of performing autologous ovarian tissue transplantation in survivors of acute leukemia.

STUDY DESIGN

Clinical, histopathological, and molecular data of 4 women with acute myeloid leukemia and 2 women with acute lymphoblastic leukemia who underwent ovarian tissue cryopreservation and transplantation were analyzed in this case series. Following cryopreservation of 66% to 100% of an ovarian cortex with a slow freezing method, all women received high-dose multiagent alkylating preconditioning chemotherapy for allogeneic hematopoietic stem cell transplantation. Before the ovarian tissue transplantation, (1) antral follicle counts, serum antimüllerian hormone and follicle-stimulating hormone levels were assessed to confirm primary ovarian insufficiency; (2) all recipients were cleared by their hematologist-oncologists; (3) representative cortical strips were screened for leukemia infiltration by histologic (hematoxylin and eosin staining), immunohistochemical (CD3, CD20, CD34, CD68, CD117, CD163, PAX-5, Tdt, lysozyme, and MPO), and molecular marker evaluation (BCR/ABL p190 and AML1/ETO) where appropriate.

RESULTS

The median age was 20 years (interquartile range, 15-32) at ovarian tissue cryopreservation. Before undergoing hematopoietic stem cell transplantation, all patients received induction or consolidation chemotherapy that included cytarabine + daunorubicin or Berlin-Frankfurt-Munich-95 protocol and were in remission. The mean serum antimüllerian hormone was 1.9±1.7 ng/mL before ovarian tissue cryopreservation. In all cases, ovarian tissue screening for leukemic cells was negative. Ovarian transplantation was performed laparoscopically with or without robotic assistance, after a median of 74.5 months (interquartile range, 41-120) after ovarian tissue cryopreservation. Ovarian function resumed in all patients after a median of 3.0 months (range, 2.5-4.0), and 2 women had 1 live birth each. The median graft longevity was 35.5 months (interquartile range, 18-57) after ovarian tissue transplantation. After a median follow-up of 51 months (interquartile range, 20-74), all patients remained relapse-free. In 1 patient, the graft was removed during cesarean delivery and was negative for immunochemical leukemia markers.

CONCLUSION

Our long-term follow-up demonstrated no evidence of disease relapse after ovarian tissue transplantation in patients with acute leukemia who received allogeneic hematopoietic stem cell transplantation. This safety profile may be explained by the fact that these patients are induced into remission by nongonadotoxic induction chemotherapy before undergoing ovarian tissue cryopreservation. We propose that ovarian tissue cryopreservation should not be excluded as a fertility preservation option for young women with leukemia who are due to receive preconditioning chemotherapy before allogeneic hematopoietic stem cell transplantation.

Expert consensus on fertility preservation in hematopoietic stem cell transplantation in girls in China

Aims: Preconditioning before hematopoietic stem cell transplantation (HSCT) seriously damages the ovarian function and causes female infertility. This consensus focuses on the fertility preservation(FP) for girls needing HSCT, aim to make doctors in different disciplines aware of the importance, necessity and technique of ovarian protection.Materials and methods: Summarizing relevant literature and organizing multidisciplinary experts, including obstetrics and gynecology, reproductive medicine, oncology, pediatrics and hematology for full discussion.Results: Individuals exposed to HSCT in childhood are at higher risk of loss of fertility. Considering the high risk of premature ovarian insufficiency (POI) after conditioning and negative impact of POI on fertility, physical and mental health, it is absolutely necessary to protect fertility before HSCT conditioning. Ovarian tissue cryopreservation is the main fertility preservation option for these population.Conclusions: Fertility preservation before HSCT conditioning is crucial. Ovarian tissue cryopreservation is often the only option for these population.

Optimizing the Ovarian Tissue Cryopreservation in the 'Oncofertility' Institutional Program at an Italian National Cancer Institute

BACKGROUND

The majority of female cancer patients undergoing anticancer treatments are at risk of experiencing 'cancer treatment-related infertility', which can result in permanent damage to their reproductive prospects. Among the fertility preservation methods, ovarian tissue cryopreservation (OTC) has emerged as an alternative for these patients. The Cancer Institute of Bari initiated a research program to assess the feasibility of OTC. This study compares the viability of ovarian cortical fragments cryopreserved using slow freezing (SF) and ultra-rapid freezing (URF) methods.

METHODS

Ovarian cortex biopsies were obtained from 11 fertile women enrolled in our oncofertility service between June 2022 and January 2023. After tissue collection, a histological assessment was performed before cryopreservation. OTC was carried out using both SF and URF methods. Six months later, thawed samples were evaluated for follicle counts and histological integrity.

RESULTS

No statistically significant difference was observed in the proportion of intact follicles (means of 31.5% and 73.0% in the SF and URF groups, respectively; p = 0.064). However, there was a significant difference in the number of follicles between the SF group (n = 149) and the URF group (n = 37) (p = 0.046).

CONCLUSIONS

We assessed the viability of ovarian cortex after freezing and thawing, focusing on the structural integrity of follicles. Our findings suggest that there are no significant differences between the SF and URF methods.

Long-Term Survival and Functional Recovery of Cryopreserved Vascularized Groin Flap and Below-the-Knee Rat Limb Transplants

Effective cryopreservation of large tissues, limbs, and organs has the potential to revolutionize medical post-trauma reconstruction options and organ preservation and transplantation procedures. To date, vitrification and directional freezing are the only viable methods for long-term organ or tissue preservation, but are of limited clinical relevance. This work aimed to develop a vitrification-based approach that will enable the long-term survival and functional recovery of large tissues and limbs following transplantation. The presented novel two-stage cooling process involves rapid specimen cooling to subzero temperatures, followed by gradual cooling to the vitrification solution (VS) and tissue glass transition temperature. Flap cooling and storage were only feasible at temperatures equal to or slightly lower than the VS Tg (i.e., -135°C). Vascularized rat groin flaps and below-the-knee (BTK) hind limb transplants cryopreserved using this approach exhibited long-term survival (>30 days) following transplantation to rats. BTK-limb recovery included hair regrowth, normal peripheral blood flow, and normal skin, fat, and muscle histology. Above all, BTK limbs were reinnervated, enabling rats to sense pain in the cryopreserved limb. These findings provide a strong foundation for the development of a long-term large-tissue, limb and organ preservation protocol for clinical use.

Prior exposure to chemotherapy does not reduce the in vitro maturation potential of oocytes obtained from ovarian cortex in cancer patients

STUDY QUESTION

Does chemotherapy exposure affect IVM potential of immature oocytes retrieved from the ovarian cortex following ovarian tissue cryopreservation (OTC) for fertility preservation?

SUMMARY ANSWER

The IVM potential of oocyte retrieved from ovarian cortex following OTC is not affected by prior exposure to chemotherapy but primarily dependent on patient's age, while successful retrieval of immature oocytes from the ovarian tissue is negatively affected by chemotherapy and its timing.

WHAT IS KNOWN ALREADY

The potential and feasibility of IVM in premenarche patients was previously demonstrated, in smaller studies. The scarce data that exist on the IVM potential of oocytes retrieved during OTC following chemotherapy support the feasibility of this process, however, this was not previously shown in the premenarche cancer patients population or in larger cohorts.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study evaluating 229 cancer patients aged 1-39 years with attempted retrieval of oocytes from the ovarian tissue and the medium following OTC in a university affiliated fertility preservation unit between 2002 and 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 172 chemotherapy naïve and 57 chemotherapy exposed patients aged 1-39 years underwent OTC in university affiliated tertiary infertility and IVF center. OTC and IVM outcomes were compared between the chemotherapy naïve and exposed groups. The main outcome measure was mean IVM rate per patient in the chemotherapy naïve and exposed groups, with subgroup analysis of a 1:1 chemotherapy exposed group matched for age at OTC and type of malignancy. We additionally analyzed premenarche and postmenarche patients' outcomes separately and investigated the effect of time from chemotherapy to IVM, malignancy type and chemotherapy regimen on oocyte number and IVM outcomes in the chemotherapy exposed group.

MAIN RESULTS AND THE ROLE OF CHANCE

While the number of retrieved oocytes and percentage of patients with at least one oocyte retrieved was higher in the chemotherapy naïve group (8.7 ± 7.9 versus 4.9 ± 5.6 oocytes and 87.2% versus 73.7%, P < 0.001 and P = 0.016, respectively), IVM rate and number of mature oocytes were comparable between the groups (29.0 ± 25.0% versus 28. 9 ± 29.2% and 2.8 ± 3.1 versus 2.2 ± 2.8, P = 0.979 and P = 0.203, respectively). Similar findings were shown in subgroup analyses for premenarche and postmenarche groups. The only parameter found to be independently associated with IVM rate in a multivariable model was menarche status (F = 8.91, P = 0.004). Logistic regression models similarly showed that past chemotherapy exposure is negatively associated with successful retrieval of oocytes while older age and menarche are predictive of successful IVM. An age and the type of malignancy matched (1:1) chemotherapy naïve and exposed groups were created (25 patients in each group). This comparison demonstrated similar IVM rate (35.4 ± 30.1% versus 31.0 ± 25.2%, P = 0.533) and number of matured oocytes (2.7 ± 3.0. versus 3.0 ± 3.9 oocytes, P = 0.772). Type of malignancy and chemotherapy regimen including alkylating agents were not associated with IVM rate.

LIMITATIONS, REASONS FOR CAUTION

This study's inherited retrospective design and the long study period carries the possible technological advancement and differences. The chemotherapy exposed group was relatively small and included different age groups. We could only evaluate the potential of the oocytes to reach metaphase II in vitro but not their fertilization potential or clinical outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

IVM is feasible even after chemotherapy broadening the fertility preservation options of cancer patients. The use of IVM for fertility preservation, even after exposure to chemotherapy, should be further studied for optimal postchemotherapy timing safety and for the in vitro matured oocytes potential for fertilization.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study by any of the authors. The authors report that no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Comparison of angiogenic potential in vitrified vs. slow frozen human ovarian tissue

Vitrification of ovarian tissue is a promising alternative approach to the traditional slow freezing method. Few empirical investigations have been conducted to determine the angiogenic profiles of these two freezing methods. In this study we aimed to answer the question whether one of the cryopreservation methods should be preferred based on the secretion of angiogenic factors. Tissue culture with reduced oxygen (5%) was conducted for 48 h with samples of fresh, slow frozen/thawed and vitrified/rapid warmed ovarian cortex tissue from 20 patients. From each patient, tissue was used in all three treatment groups. Tissue culture supernatants were determined regarding cytokine expression profiles of angiogenin, angiopoietin-2, epidermal growth factor, basic fibroblast growth factor, heparin binding epidermal growth factor, hepatocyte growth factor, Leptin, Platelet-derived growth factor B, placental growth factor and vascular endothelial growth factor A via fluoroimmunoassay. Apoptotic changes were assessed by TUNEL staining of cryosections and supplemented by hematoxylin and eosin and proliferating cell nuclear antigen staining. Comparing the angiogenic expression profiles of vitrified/rapid warmed tissue with slow frozen/thawed tissue samples, no significant differences were observed. Detection of apoptotic DNA fragmentation via TUNEL indicated minor apoptotic profiles that were not significantly different comparing both cryopreservation methods. Vitrification of ovarian cortical tissue does not appear to impact negatively on the expression profile of angiogenic factors and may be regarded as an effective alternative approach to the traditional slow freezing method.

Different Impacts of Cryopreservation in Endothelial and Epithelial Ovarian Cells

The aim of our laboratory-based study was to investigate the extent of delayed-onset cell death after cryopreservation in endothelial and epithelial cell lines of ovarian origin. We found differences in percentages of vital cells directly after warming and after cultivation for 48 to 72 h. A granulosa cell line of endothelial origin (KGN) and an epithelial cell line (OvCar-3) were used. In both DMSO-containing and DMSO-free protocols, significant differences in vitality rates between the different cell lines when using open and closed vitrification could be shown (DMSO-containing: KGN open vs. OvCar open, p = 0.001; KGN closed vs. OvCar closed, p = 0.001; DMSO-free: KGN open vs. OvCar open, p = 0.001; KGN closed vs. OvCar closed, p = 0.031). Furthermore, there was a marked difference in the percentage of vital cells immediately after warming and after cultivation for 48 to 72 h; whereas the KGN cell line showed a loss of cell viability of 41% using a DMSO-containing protocol, the OvCar-3 cell loss was only 11% after cultivation. Using a DMSO-free protocol, the percentages of late-onset cell death were 77% and 48% for KGN and OvCar-3 cells, respectively. Our data support the hypothesis that cryopreservation-induced damage is cell type and cryoprotective agent dependent.

Outcomes of Different In Vitro Maturation Procedures for Oocyte Cryopreservation for Fertility Preservation and yet Another Live Birth in a Cancer Patient

To ensure patient care in an oncological fertility preservation (FP) programme, specialists must provide technology that best suits the patients' clinical conditions. In vitro oocyte maturation (IVM) and ovarian tissue cryopreservation (OTC) are possible fertility preservation treatments for women in need of urgent oncological treatment. IVM consists of the retrieval of immature oocytes from small antral follicles, with no or minimal ovarian stimulation by gonadotropins. Therefore, IVM has become a pertinent option for fertility preservation, especially for cases whereby ovarian stimulation is unfeasible or contra-indicated. Existing data on immature oocytes, retrieved transvaginally (OPU-IVM) or extracted from ovarian tissue 'ex vivo' (OTO-IVM), are still limited on technical consistency, efficacy, and safety. The present retrospective cohort study includes 89 women undergoing fertility preservation using IVM methodologies and 26 women undergoing ovarian stimulation (OS) in concomitant period. In total, 533 immature oocytes were collected from IVM patients, achieving a maturation rate of 57% and 70% in OTO-IVM and 73% and 82% in OPU-IVM at 24 h and 48 h in culture, respectively. The observed high maturation rates might be due to the use of patients' serum in its innate status, i.e., without heat-inactivation. This permitted 7.6 ± 5.7 and 4.6 ± 4.9 oocytes to be vitrified in OTO-IVM and OPU-IVM, respectively, compared to 6.8 ± 4.6 from OS patients. Regarding OS patients, two of them underwent embryo transfer following the insemination of warmed oocytes after complete remission, resulting in a single live birth from one patient. Upon follow-up of two OTO-IVM patients after the termination of their oncological treatment, a total of 11 warmed oocytes lead to a transfer of a single embryo, but pregnancy was not achieved. From OPU-IVM, six embryos were transferred in three patients 4.25 years after oocyte vitrification, leading to the live birth of a healthy boy. The present case of live birth is among the first cases reported so far and supports the notion that IVM might be a relevant and safe FP option for cancer patients when oocyte preservation is required but ovarian stimulation is contra-indicated.

A comprehensive review and update on human fertility cryopreservation methods and tools

The broad conceptualization of fertility preservation and restoration has become already a major concern in the modern western world since a large number of individuals often face it in the everyday life. Driven by different health conditions and/or social reasons, a variety of patients currently rely on routinely and non-routinely applied assisted reproductive technologies, and mostly on the possibility to cryopreserve gametes and/or gonadal tissues for expanding their reproductive lifespan. This review embraces the data present in human-focused literature regarding the up-to-date methodologies and tools contemporarily applied in IVF laboratories' clinical setting of the oocyte, sperm, and embryo cryopreservation and explores the latest news and issues related to the optimization of methods used in ovarian and testicular tissue cryopreservation.

Impacts of vitrification on the transcriptome of human ovarian tissue in patients with gynecological cancer

Objective: This study investigated the effects of a vitrification/warming procedure on the mRNA transcriptome of human ovarian tissues.

Design: Human ovarian tissues were collected and processed through vitrification (T-group) and then subjected to RNA sequencing (RNA-seq) analysis, HE, TdT-mediated dUTP nick-end labeling (TUNEL), and real-time quantitative PCR, and the results were compared to those of the fresh group (CK).

Results: A total of 12 patients, aged 15–36 years old, with a mean anti-Müllerian hormone level of 4.57 ± 3.31 ng/mL were enrolled in this study. According to the HE and TUNEL results, vitrification effectively preserved human ovarian tissue. A total of 452 significantly dysregulated genes (|log2FoldChange| &gt; 1 and p &lt; 0.05) were identified between the CK and T groups. Among these, 329 were upregulated and 123 were downregulated. A total of 372 genes were highly enriched for 43 pathways (p &lt; 0.05), which were mainly related to systemic lupus erythematous, cytokine–cytokine receptor interaction, the TNF signaling pathway, and the MAPK signaling pathway. IL10, AQP7, CCL2, FSTL3, and IRF7 were significantly upregulated (p &lt; 0.01), while IL1RN, FCGBP, VEGFA, ACTA2, and ASPN were significantly downregulated in the T-group (p &lt; 0.05) compared to the CK group, which agreed with the results of the RNA-seq analysis.

Conclusion: These results showed (for the first time to the authors’ knowledge) that vitrification can induce changes in mRNA expression in human ovarian tissues. Further molecular studies on human ovarian tissues are required to determine whether altered gene expression could result in any downstream consequences.

Minimal residual disease detection by mutation-specific droplet digital PCR for leukemia/lymphoma

Minimal residual disease (MRD) is usually defined as the small number of cancer cells that remain in the body after treatment. The clinical significance of MRD kinetics is well recognized in treatment of hematologic malignancies, particularly acute lymphoblastic leukemia (ALL). Real time quantitative PCR targeting immunoglobulin (Ig) or T-cell receptor (TCR) rearrangement (PCR-MRD), as well as multiparametric flow cytometric analysis targeting antigen expression, are widely used in MRD detection. In this study, we devised an alternative method to detect MRD using droplet digital PCR (ddPCR), targeting somatic single nucleotide variants (SNVs). This ddPCR-based method (ddPCR-MRD) had sensitivity up to 1E-4. We assessed ddPCR-MRD at 26 time points from eight T-ALL patients, and compared it to the results of PCR-MRD. Almost all results were concordant between the two methods, but ddPCR-MRD detected micro-residual disease that was missed by PCR-MRD in one patient. We also measured MRD in stored ovarian tissue of four pediatric cancer patients, and detected 1E-2 of submicroscopic infiltration. Considering the universality of ddPCR-MRD, the methods can be used as a complement for not only ALL, but also other malignant diseases regardless of tumor-specific Ig/TCR or surface antigen patterns.

Live birth rate after female fertility preservation for cancer or haematopoietic stem cell transplantation: a systematic review and meta-analysis of the three main techniques; embryo, oocyte and ovarian tissue cryopreservation

STUDY QUESTION

What are the chances of achieving a live birth after embryo, oocyte and ovarian tissue cryopreservation (OTC) in female cancer survivors?

SUMMARY ANSWER

The live birth rates (LBRs) following embryo and oocyte cryopreservation are 41% and 32%, respectively, while for IVF and spontaneous LBR after tissue cryopreservation and transplantation, these rates are 21% and 33%, respectively.

WHAT IS KNOWN ALREADY

Currently, fertility preservation (FP) has become a major public health issue as diagnostic and therapeutic progress has made it possible to achieve an 80% survival rate in children, adolescents and young adults with cancer. In the latest ESHRE guidelines, only oocyte and embryo cryopreservation are considered as established options for FP. OTC is still considered to be an innovative method, while it is an acceptable FP technique in the American Society for Reproductive Medicine guidelines. However, given the lack of studies on long-term outcomes after FP, it is still unclear which technique offers the best chance to achieve a live birth.

STUDY DESIGN, SIZE, DURATION

We performed a systematic review and meta-analysis of published controlled studies. Searches were conducted from January 2004 to May 2021 in Medline, Embase and the Cochrane Library using the following search terms: cancer, stem cell transplantation, FP, embryo cryopreservation, oocyte vitrification, OTC and reproductive outcome.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 126 full-text articles were preselected from 1436 references based on the title and abstract and assessed via the Newcastle-Ottawa Quality Assessment Scale. The studies were selected, and their data were extracted by two independent reviewers according to the Cochrane methods. A fixed-effect meta-analysis was performed for outcomes with high heterogeneity.

MAIN RESULTS AND THE ROLE OF CHANCE

Data from 34 studies were used for this meta-analysis. Regarding cryopreserved embryos, the LBR after IVF was 41% (95% CI: 34-48, I2: 0%, fixed effect). Concerning vitrified oocytes, the LBR was 32% (95% CI: 26-39, I2: 0%, fixed effect). Finally, the LBR after IVF and the spontaneous LBR after ovarian tissue transplantation were 21% (95% CI: 15-26, I2: 0%, fixed-effect) and 33% (95% CI: 25-42, I2: 46.1%, random-effect), respectively. For all outcomes, in the sensitivity analyses, the maximum variation in the estimated percentage was 1%.

LIMITATIONS, REASONS FOR CAUTION

The heterogeneity of the literature prevents us from comparing these three techniques. This meta-analysis provides limited data which may help clinicians when counselling patients.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the need for long-term follow-up registries to assess return rates, as well as spontaneous pregnancy rates and birth rates after FP.

STUDY FUNDING/COMPETING INTEREST(S)

This work was sponsored by an unrestricted grant from GEDEON RICHTER France. The authors have no competing interests to declare.

REGISTRATION NUMBER

CRD42021264042.

The ovaries of transgender men indicate effects of high dose testosterone on the primordial and early growing follicle pool

Androgens are essential in normal ovarian function and follicle health but hyperandrogenism, as seen in polycystic ovary syndrome, is associated with disordered follicle development. There are few data on the effect of long-term exposure to high levels of testosterone as found in transgender men receiving gender-affirming endocrine therapy. In this study, we investigate the effect of testosterone on the development, morphological health and DNA damage and repair capacity of human ovarian follicles in vivo and their survival in vitro. Whole ovaries were obtained from transgender men (mean age: 27.6 ± 1.7 years; range 20-34 years, n = 8) at oophorectomy taking pre-operative testosterone therapy. This was compared to cortical biopsies from age-matched healthy women obtained at caesarean section (mean age: 31.8±1.5 years; range= 25-35 years, n=8). Cortical tissues were dissected into fragments and either immediately fixed for histological analysis or cultured for 6 days and subsequently fixed. Follicle classification and morphological health were evaluated from histological sections stained with H&E and expression of γH2AX as a marker of DNA damage by IHC. In uncultured tissue, testosterone exposure was associated with reduced follicle growth activation, poor follicle health and increased DNA damage. After 6 days of culture, there was enhanced follicle activation compared to control with further deterioration in morphological health and increased DNA damage. These data indicate that high circulating concentrations of testosterone have effects on the primordial and small-growing follicles of the ovary. These results may have implications for transgender men receiving gender-affirming therapy prior to considering pregnancy or fertility preservation measures.

Ovarian Function and Spontaneous Pregnancy After Hematopoietic Stem Cell Transplantation for Leukemia Before Puberty: An L.E.A. Cohort Study

Ovarian function impairment and infertility are among the most frequent late effects after hematopoietic stem cell transplantation (HSCT). The aim of this study was to evaluate ovarian function, occurrence of premature ovarian insufficiency (POI), and spontaneous pregnancy in a large cohort of adult survivor women who had undergone HSCT for leukemia before puberty. We conducted a retrospective observational study in women from the national cohort L.E.A., the long-term French follow-up program after childhood leukemia. The median follow-up duration was 18 years (14.2-23.3) after HSCT. Among 178 women, 106 (60%) needed pubertal induction with hormone substitution treatment, whereas 72 (40%) had spontaneous menarche. After spontaneous menarche, 33 (46%) developed POI, mostly within 5 years of HSCT. Older age at time of HSCT and cryopreservation of ovarian tissue appeared as significant risk factors for POI. More than 65% of patients who underwent HSCT before the age of 4.8 years had spontaneous menarche, and almost 50% didn't have POI at last evaluation, whereas more than 85% with HSCT after the age of 10.9 years didn't have spontaneous menarche and needed induction of puberty with hormone replacement therapy. Twenty-two women (12%) had at least one spontaneous pregnancy, with 17 live-births, 14 miscarriages, 4 legal abortions, and 2 therapeutic abortions. These results add supplementary data to better counsel patients and their families on the chances of ovarian residual function and pregnancy after HSCT, as well as on the potential interest of fertility preservation.

The effect of high-throughput vitrification of human ovarian cortex tissue on follicular viability: a promising alternative to conventional slow freezing?

BACKGROUND

The standard procedure most frequently used for ovarian tissue cryopreservation (OTC) is slow freezing, while vitrification has been proposed as promising alternative and has built an impressive catalog of success in fertility laboratories regarding cryopreservation of oocytes and embryos.

METHODS

We developed and evaluated a high-throughput protocol for vitrification of human ovarian tissue suitable for clinical processing. Follicular viability was assessed via calcein staining prior and after cryopreservation analyzing ovarian tissue of a cohort of 30 patients.

RESULTS

We found no significant differences regarding follicular viability between slow frozen and vitrified cortex tissue samples 24 h after thawing and rapid warming. Follicular viability of thawed and rapid warmed samples was not significantly different in comparison to fresh samples, indicating high proportions of follicular survival rates with both methods.

CONCLUSIONS

High-throughput vitrification is a promising option in a clinical setting. More research is required to determine the status of other tissue-specific quality indicators potentially influencing on autotransplantation.

Transplantation of small ovarian tissue fragments using pipelle device is effective: method evaluation and reproductive outcomes

PURPOSE

To assess the feasibility, effectiveness, and reproductive outcomes of transplantation of tiny cryopreserved ovarian pieces through a pipelle cannula during laparoscopic surgery.

METHODS

A retrospective study of patients who underwent ovarian tissue transplantation for fertility restoration between 2004 and 2022. The "pipelle group" had their ovarian cortex cut into tiny pieces of ~ 1-2 mm3 before cryopreservation. The pieces were too small to be handled and transplanted via standard laparoscopic tools. Transplantation was performed using a pipelle cannula during laparoscopic surgery. The "control group" underwent transplants of ovarian cortex pieces 1-2 mm thick, measuring approximately 25-50 mm2 pieces, using standard procedures.

RESULTS

The pipelle group consisted of 4 patients aged 19, 21, 27, and 28 years old at ovarian tissue cryopreservation (OTC). The control group consisted of 14 patients aged 21-30 years old. All pipelle patients restored their endocrine activity, and all of them conceived. FSH levels dropped during the first 3 months following the pipelle transplant. IVF cycle outcomes were similar for both groups. All patients from the pipelle group conceived, resulting in 5 pregnancies and 4 live births (one patient had 2 deliveries, and one additional pregnancy is ongoing), compared to the control group, where 8 patients achieved a total of 20 pregnancies and 18 live births.

CONCLUSION

Pipelle transplantation for tiny cryopreserved ovarian pieces is feasible and effective. This study opens a door for patients who had their ovaries cut into small pieces and may even simplify the procedure in some instances, making ovarian transplant more accessible.

TRIAL REGISTRATION

(#6531-19-SMC) [18/09/2019].

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

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

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

AIM

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

METHODS

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

RECOMMENDATIONS

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

Ovarian Tissue Cryopreservation in Children and Adolescents

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

When Electrospun Fiber Support Matters: In Vitro Ovine Long-Term Folliculogenesis on Poly (Epsilon Caprolactone) (PCL)-Patterned Fibers

Current assisted reproduction technologies (ART) are insufficient to cover the slice of the population needing to restore fertility, as well as to amplify the reproductive performance of domestic animals or endangered species. The design of dedicated reproductive scaffolds has opened the possibility to better recapitulate the reproductive 3D ovarian environment, thus potentially innovating in vitro folliculogenesis (ivF) techniques. To this aim, the present research has been designed to compare ovine preantral follicles in vitro culture on poly(epsilon-caprolactone) (PCL)-based electrospun scaffolds designed with different topology (Random vs. Patterned fibers) with a previously validated system. The ivF performances were assessed after 14 days under 3D-oil, Two-Step (7 days in 3D-oil and on scaffold), or One-Step PCL protocols (14 days on PCL-scaffold) by assessing morphological and functional outcomes. The results show that Two- and One-Step PCL ivF protocols, when performed on patterned scaffolds, were both able to support follicle growth, antrum formation, and the upregulation of follicle marker genes leading to a greater oocyte meiotic competence than in the 3D-oil system. In conclusion, the One-Step approach could be proposed as a practical and valid strategy to support a synergic follicle-oocyte in vitro development, providing an innovative tool to enhance the availability of matured gametes on an individual basis for ART purposes.

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.

Guidance on the need for contraception related to use of pharmaceuticals: the Japan Agency for Medical Research and Development Study Group for providing information on the proper use of pharmaceuticals in patients with reproductive potential

BACKGROUND

The U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) have published guidelines on the use of cancer treatments in young people of reproductive potential. However, no such guideline is available in Japan. Therefore, this project aimed to gather relevant data and draft a respective guidance paper.

METHODS

From April 2019 to March 2021, the Study Group for Providing Information on the Proper Use of Pharmaceuticals in Patients with Reproductive Potential at the Japan Agency for Medical Research and Development gathered opinions from experts in reproductive medicine, toxicology, and drug safety measures. The group considered these opinions, the FDA and EMA guidelines, and relevant Japanese guidelines and prepared a guidance paper, which they sent to 19 related organizations for comment.

RESULTS

By November 2020, the draft guidance paper was completed and sent to the related organizations, 17 of which provided a total of 156 comments. The study group finalized the guidance paper in March 2021.

CONCLUSIONS

The "Guidance on the Need for Contraception Related to Use of Pharmaceuticals" (The report of the Study Group for Providing Information on the Proper Use of Pharmaceuticals in Patients with Reproductive Potential, Research on Regulatory Science of Pharmaceuticals and Medical Devices, Japan Agency for Medical Research and Development: JP20mk0101139) is expected to help Japanese healthcare professionals provide fertility-related care and advice to adolescents, and young adults with cancer and their families.

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.

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

RESEARCH QUESTION

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Evaluation of an alternative heterotopic transplantation model for ovarian tissue to test pharmaceuticals improvements for fertility restoration

BACKGROUND

Ovarian tissue cryopreservation and transplantation (OTCTP) is currently the main option available to preserve fertility in prepubertal patients undergoing aggressive cancer therapy treatments. However, a major limitation of OTCTP is follicle loss after transplantation. The mouse is a model of choice for studying ovarian function and follicle development after ovarian tissue grafting in vivo. In these mouse models, ovarian tissue or ovaries can be transplanted to different sites. Our aim was to evaluate a new alternative to heterotopic transplantation models that could be useful to test pharmaceutical improvement for ovarian grafts after OTCTP.

METHODS

Slow frozen murine whole ovaries were transplanted into the mouse ears (between the external ear skin layer and the cartilage). Ovarian transplants were recovered after 3, 14 or 21 days. Grafts were analyzed by immunohistochemistry and follicle density analyses were performed.

RESULTS

An increase of ovarian vascularization (CD31 and Dextran-FITC positive staining), as well as cellular proliferation (Ki67 staining) were observed 3 weeks after transplantation in comparison to 3 days. Fibrosis density, evaluated after Van Gieson staining, decreased 3 weeks after transplantation. Furthermore, transplantation of cryopreserved ovaries into ovariectomized mice favored follicle activation compared to transplantation into non-ovariectomized mice.

CONCLUSION

The present study indicates that surgical tissue insertion in the highly vascularized murine ear is an effective model for ovarian grafting. This model could be helpful in research to test pharmaceutical strategies to improve the function and survival of cryopreserved and transplanted ovarian tissue.