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

Developments in pharmacotherapy for the preservation of ovarian function during cancer treatment

INTRODUCTION

Cancer is one of the major causes of human death, and anti-cancer therapy often results in premature ovarian failure and infertility, depending on factors such as age, initial ovarian reserve, and chemotherapy type and dose. Fertility preservation procedures, such as oocyte, embryo, and ovarian cortex cryopreservation, can help women achieve pregnancy after cancer treatment. However, the development of pharmacological therapies to protect ovarian function during chemotherapy would represent a significant advancement.

AREAS COVERED

We searched the published articles in PubMed up to December 2024, containing key words '"chemotherapy",' 'cancer,' '"ovarian protection",' '"pharmacological therapy",' '"ovarian reserve"' and '"fertility".' Chemotherapeutic agents act via various mechanisms in the human ovary, including direct DNA damage leading to oocyte apoptosis, as well as damage to ovarian stroma and microvascular architecture. In recent years, numerous protective agents have emerged, showing promise in protecting ovaries from chemotherapy-induced damage. However, most studies have relied on animal models, and only a limited number have directly tested these agents in human ovarian tissue. At present, no pharmacological treatment has been conclusively proven effective for preserving fertility.

EXPERT OPINION

A comprehensive understanding of the mechanisms underlying chemotherapy-induced ovarian damage is critical for the development of efficient and targeted pharmacological therapies.

Short-Term Bovine Ovarian Tissue Heterotopic Autotransplantation: VEGF Beneficial and Detrimental Effects

Ovarian tissue transplantation (OTT) has been suggested as an alternative to preserving female fertility in livestock species, as currently performed in women. The OTT technique has been tested as xenografting or autografting in different body sites and animal species. Currently, there are no reports available regarding the autotransplantation of ovarian tissue using the bovine model and also testing the effect of vascular endothelial growth factor (VEGF) on graft survival. This study evaluated the effects of ovarian tissue short-term exposure to VEGF before heterotopic autotransplantation into a subcutaneous site (flank region) for 7 days in cattle. The initial finding was that after OTT and without pre-exposure to VEGF, the ovarian grafts had 42% of normal preantral follicles, which indicates a substantial step forward for this technique in cattle. Furthermore, VEGF exposure actively facilitated the process of neoangiogenesis, the proliferation capability of the stromal cells for activation of the cell cycle, maintained the balance between types I and III collagen fibers, and reduced the total collagen of the grafted tissue. Moreover, ovarian fragments previously exposed to VEGF tended to have greater follicular density; however, a detrimental effect of VEGF on follicular morphology was noticed. In conclusion, this study marks a significant step forward in bovine OTT and provides a foundation for further investigations into the specific pathways, stages, and durations of VEGF exposure to unveil strategies for refining ovarian transplantation techniques in cattle and other species.

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.

Utility and Outcomes of Ovarian Tissue Cryopreservation and Transplantation for Gynecologic Cancers: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the utility, success, and safety of ovarian tissue cryopreservation and autologous cryopreserved ovarian tissue transplantation for fertility preservation in patients with gynecologic cancers.

DATA SOURCES

A comprehensive search was performed of the MEDLINE, EMBASE, ClinicalTrials.gov , and Cochrane Library databases to identify relevant studies on the utility and outcomes of ovarian tissue cryopreservation and autologous cryopreserved ovarian tissue transplantation for gynecologic cancers from inception until January 23, 2024.

METHODS OF STUDY SELECTION

Two reviewers independently performed the study selection, data extraction, and risk-of-bias assessment, and the results were then reviewed together. Twenty-three studies were included in the current systematic review.

TABULATION, INTEGRATION, AND RESULTS

The resultant data were meta-analyzed to produce a pooled-effect estimate of the utility of ovarian tissue cryopreservation and autologous transplantation in gynecologic cancers as a proportion of all indications. We found that 7.5% and 9.6% of women undergoing ovarian tissue cryopreservation and autologous transplantation, respectively, had gynecologic cancers. In comparison, hematologic malignancies and breast cancer accounted for approximately 66.0% of all indications for these procedures. The return rate for autologous cryopreserved ovarian tissue transplantation in gynecologic cancers (6.0%) was not statistically different from those for other indications. Among women with gynecologic cancer who underwent ovarian stimulation, 27.3% had at least one child, and the ovarian endocrine function was restored in 78.1% of the women after autologous transplantation. The median graft longevity was 32 months, and no graft-site recurrence was reported after autologous transplantation in women with gynecologic cancer.

CONCLUSION

Our results suggest that ovarian tissue cryopreservation and autologous transplantation are feasible options for preserving ovarian function in women with gynecologic cancers, although ovarian tissue cryopreservation is underutilized, and further studies are needed to determine the longer-term outcomes of autologous transplantation.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42024498522.

Fertility Preservation and Ovarian Hyperstimulation Syndrome Management in Cancer Care: A Pathophysiological Perspective on Gonadotropin-Releasing Hormone Agonists and Antagonists

This narrative review delves into the evolving landscape of fertility preservation techniques, with a particular focus on their use in patients undergoing oncology treatment that carries a risk of ovarian insufficiency. Advances in established methods such as cryopreservation of oocytes and embryos are highlighted, and the increasing use of gonadotropin-releasing hormone (GnRH) agonists is discussed. The review also addresses the complexities and controversies associated with these approaches, such as the 'flare-up' effect associated with GnRH agonists and the potential of GnRH antagonists to reduce the risk of ovarian hyperstimulation syndrome. Despite advances in fertility preservation, the report highlights the challenges we face, including the need for personalized treatment protocols and the management of associated risks. It calls for continued research and collaboration between healthcare professionals to refine these techniques and ultimately improve reproductive outcomes for patients facing the prospect of fertility-impairing treatment.

Modeling delay of age at natural menopause with planned tissue cryopreservation and autologous transplantation

BACKGROUND

Ovarian tissue cryopreservation has been proven to preserve fertility against gonadotoxic treatments. It has not been clear how this procedure would perform if planned for slowing ovarian aging.

OBJECTIVE

This study aimed to determine the feasibility of cryopreserving ovarian tissue to extend reproductive life span and delay menopause by autotransplantation near menopause.

STUDY DESIGN

Based on the existing biological data on follicle loss rates, a stochastic model of primordial follicle wastage was developed to determine the years of delay in menopause (denoted by D) by ovarian tissue cryopreservation and transplantation near menopause. Our model accounted for (1) age at ovarian tissue harvest (21-40 years), (2) the amount of ovarian cortex harvested, (3) transplantation of harvested tissues in single vs multiple procedures (fractionation), and (4) posttransplant follicle survival (40% [conservative] vs 80% [improved] vs 100% [ideal or hypothetical]).

RESULTS

Our model predicted that, for most women aged <40 years, ovarian tissue cryopreservation and transplantation would result in a significant delay in menopause. The advantage is greater if the follicle loss after transplant can be minimized. As an example, the delay in menopause (D) for a woman with a median ovarian reserve who cryopreserves 25% of her ovarian cortex at the age of 25 years and for whom 40% of follicles survive after transplantation would be approximately 11.8 years, but this extends to 15.5 years if the survival is 80%. As another novel finding, spreading the same amount of tissue to repetitive transplants significantly extends the benefit. For example, for the same 25-year-old woman with a median ovarian reserve, 25% cortex removal, and 40% follicle survival, fractionating the transplants to 3 or 6 procedures would result in the corresponding delay in menopause (D) of 23 or 31 years. The same conditions (3 or 6 procedures) would delay menopause as much as 47 years if posttransplant follicle survival is improved to 80% with modern approaches. An interactive Web tool was created to test all variables and the feasibility of ovarian tissue freezing and transplantation to delay ovarian aging (here).

CONCLUSION

Our model predicts that with harvesting at earlier adult ages and better transplant techniques, a significant menopause postponement and, potentially, fertile life span extension can be achieved by ovarian tissue cryopreservation and transplantation in healthy women.

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.

Decellularized extracellular matrix for organoid and engineered organ culture

The repair and regeneration of tissues and organs using engineered biomaterials has attracted great interest in tissue engineering and regenerative medicine. Recent advances in organoids and engineered organs technologies have enabled scientists to generate 3D tissue that recapitulate the structural and functional characteristics of native organs, opening up new avenues in regenerative medicine. The matrix is one of the most important aspects for improving organoids and engineered organs construction. However, the clinical application of these techniques remained a big challenge because current commercial matrix does not represent the complexity of native microenvironment, thereby limiting the optimal regenerative capacity. Decellularized extracellular matrix (dECM) is expected to maintain key native matrix biomolecules and is believed to hold enormous potential for regenerative medicine applications. Thus, it is worth investigating whether the dECM can be used as matrix for improving organoid and engineered organs construction. In this review, the characteristics of dECM and its preparation method were summarized. In addition, the present review highlights the applications of dECM in the fabrication of organoids and engineered organs.

Significance and Influence of Suturing for Ovarian Tissue Transplantation

The purpose of this animal study was to verify the effect of suturing on graft function in ovarian tissue transplantation. Ovaries from 2-week-old rats were transplanted orthotopically into the ovaries of 8-week-old female Wistar rats. The various transplantation methods used were insertion into the ovarian bursa without suturing (group A: control), suturing with a single 6-0 Vicryl stitch (group B: 6-0*1), suturing with a single 10-0 Vicryl stitch (group C: 10-0*1), and suturing with three 10-0 Vicryl stitches (group D: 10-0*3). Two weeks after transplantation, the transplanted ovaries were evaluated histologically and for gene expression. Engraftment rates of the donor ovaries 14 days after transplantation were 62.5%, 100%, 91.7%, and 100% in groups A, B, C, and D, respectively, significantly lower in group A than in the other groups. In terms of gene expression, TNFα levels were significantly higher in group D, and GDF9 and follicle-stimulating hormone receptor (FSHR) levels were significantly lower in group D than in groups A and B. The number of primordial follicles evaluated by HE staining was significantly lower in groups B, C, and D than in group A. Compared to orthotopic transplantation without sutures, direct suturing to the host improved the engraftment rate, although increasing the number of sutures increased inflammatory marker levels and decreased the number of primordial follicles. We believe that it is important to perform ovarian tissue transplantation using optimal suture diameter for good adhesion, but with a minimum number of sutures to preserve ovarian function.

Comparison of orthotopic and heterotopic autologous ovarian tissue transplantation outcomes

OBJECTIVE

To compare the outcomes of orthotopic and heterotopic ovarian tissue transplantation (OTT) techniques.

DESIGN

Mixed prospective-retrospective cohort study.

SETTING

Academic hospital.

PATIENTS

A total of 14 recipients of autologous OTT.

INTERVENTIONS

Of the 14 women, 12 who received orthotopic (n = 6) or heterotopic (n = 6) transplants met the inclusion criteria. All orthotopic transplants and one heterotopic ovarian tissue transplant were performed laparoscopically. Although 5 of the 6 remaining heterotopic transplants were performed subcutaneously under local anesthesia or intravenous sedation, one was performed with robotic assistance. With the exception of one recipient who solely desired restoration of endocrine function, all underwent oocyte retrieval either to cryopreserve oocytes and embryos before the graft function ceased or because they could not otherwise conceive (hysterectomy, radiation damage, and heterotopic transplant).

MAIN OUTCOME MEASURES

Primary outcome measures were graft function and longevity, and the number of embryos generated per retrieval.

RESULTS

The mean age at ovarian tissue harvesting and transplantation was lower in patients with orthotopic vs. heterotopic transplants, although the proportion of transplanted ovarian cortex was lower in heterotopic transplant cases. All grafts restored ovarian endocrine function. Fertilization rates, the number of embryos generated per retrieval, and the mean number of nonarrested embryos were significantly lower in heterotopic OTT. However, time to function and graft longevity were similar between the groups. Although 4 of the 6 women conceived and delivered 7 children among orthotopic ovarian tissue recipients, one recipient had 3 spontaneous live births after heterotopic OTT, presumably because of the induction of function in the remaining menopausal ovary.

CONCLUSIONS

It appears that orthotopic OTT results in higher gamete and embryo quality. However, the endocrine function restoration rate and longevity are similar between the 2 approaches. When feasible, orthotopic OTT should be preferred for those who intend to conceive, although a less invasive heterotopic OTT can be performed for those who primarily desire ovarian endocrine function.

Fertility preservation in pregnant cancer patients after first-trimester abortion: a new challenge with possible solutions

Fertility preservation in pregnant women recently diagnosed with cancer can be a challenge. Raised levels of human chorionic gonadotropin (Beta-hCG) and progesterone in this population of patients may pose a problem for the prompt initiation of controlled ovarian stimulation (COS) due to a potential negative feedback of these hormones on folliculogenesis; however, it is not feasible to wait for negativization of serum beta-hCG levels before starting controlled ovarian stimulation. In literature, very few cases have been reported regarding the preservation of fertility in pregnant women recently diagnosed with cancer. We performed an extended revision of the literature to evaluate the current knowledge of the management of fertility preservation in women with cancer and we examined two cases closely. The first case study involved a cancer patient who underwent surgical abortion at 6.5 weeks of gestation followed by administration of mifepristone to detach any minimal residual trophoblast and consequently to decrease serum beta-hCG and progesterone levels before starting COS. In the second case study, the cancer patient underwent surgical abortion at 7.1 weeks of gestation and simultaneous unilateral oophorectomy for ovarian tissue cryopreservation due to a limited time for COS. By analyzing the results of these studies, it could be hypothesized that mifepristone administration may favor the decrease of serum beta-hCG and progesterone levels in order to permit rapid initiation of COS. In cases where COS is not feasible, ovarian tissue cryopreservation should be considered as an alternative fertility preservation technique.

CHEK2 signaling is the key regulator of oocyte survival after chemotherapy

Cancer treatments can damage the ovarian follicle reserve, leading to primary ovarian insufficiency and infertility among survivors. Checkpoint kinase 2 (CHEK2) deficiency prevents elimination of oocytes in primordial follicles in female mice exposed to radiation and preserves their ovarian function and fertility. Here, we demonstrate that CHEK2 also coordinates the elimination of oocytes after exposure to standard-of-care chemotherapy drugs. CHEK2 activates two downstream targets-TAp63 and p53-which direct oocyte elimination. CHEK2 knockout or pharmacological inhibition preserved ovarian follicle reserve after radiation and chemotherapy. However, the lack of specificity for CHEK2 among available inhibitors limits their potential for clinical development. These findings demonstrate that CHEK2 is a master regulator of the ovarian cellular response to damage caused by radiation and chemotherapy and warrant the development of selective inhibitors specific to CHEK2 as a potential avenue for ovario-protective treatments.

Cryopreservation of ovarian tissue as fertility preservation in young women with multiple sclerosis before stem cell transplantation

BACKGROUND

Women of fertile age who receive autologous hematopoietic stem cell transplantation (AHSCT) due to multiple sclerosis (MS) are at risk of loss of ovarian function and infertility because of the conditioning regimen with alkylating agents.

OBJECTIVE

To present our data on fertility preservation by ovarian tissue cryopreservation (OTC) in young women with MS before AHSCT.

METHODS

Retrospective, observational cohort study RESULTS: Eight women had OTC. After AHSCT four had premature ovarian insufficiency (POI), and two of these had autotransplantation of their cryopreserved ovarian tissue. Both women regained ovarian function, and a spontaneous pregnancy was achieved resulting in the delivery of a healthy baby.

CONCLUSION

OTC preserves fertility in young women with MS at risk of POI.

Drastic Loss of Antral Follicles Due to Gene Expression Dysregulation Occurs on the First Day After Subcutaneous Ovarian Transplantation

Ovarian cryopreservation is an alternative for the preservation of fertility, and the subcutaneous transplantation site is considered one of the most promising. Studies evaluating the follicular growth and its relationship with gene expression and vascular perfusion are essential for improving this technique and its clinical application. Thus, the aim of this study was to evaluate the effect of subcutaneous autotransplantation and vitrification on follicular growth and atresia and their relationship with vascular perfusion and gene expression. Therefore, female mice were ovariectomized, and the ovaries were divided in two experimental groups (1) vitrified (treatment, n = 97) and (2) not vitrified (control, n = 97) and subsequently were transplanted. Then grafts, from both groups, were recovered after 1, 12, or 23 days (D1, D12, D23) and subjected to follicular quantification, morphometry, and qPCR. Non-transplanted ovaries (D0) were also used. The estrous cycle and vascular perfusion were monitored throughout the experiment. On D9, 100% of the animals had reestablished their estrous cycles (p > 0.05). Blood perfusion at the transplant site was similar for both treatments (p > 0.05), with greater perfusion at the site of vitrified transplants only on D1 (p < 0.05). A drastic reduction in the number of antral follicles and an increased number of atretic follicles were observed on D1 (p < 0.0001), associated with upregulation of Casp3, Fshr, and Igf1r; and downregulation of Bax, Acvr1, Egfr, and Lhcgr (p < 0.05). Our findings indicate that the first day after subcutaneous transplantation is a critical period for follicular survival, with intense follicular atresia independent of Bax upregulation.

Determinants of transplantation success with cryopreserved ovarian tissue: data from 196 women of the FertiPROTEKT network

STUDY QUESTION

What are the pregnancy and live birth rates for ovarian tissue transplantation and which factors are associated with the success rate?

SUMMARY ANSWER

Pregnancy and live birth rates per transplanted woman are 32.7% and 26.5% and success rate is associated with female age and first versus repeated transplantation.

WHAT IS KNOWN ALREADY

Live birth rates after ovarian tissue transplantations have been reported to be between around 24% and 41% per patient. Success rates seem to be negatively associated with increasing female age at the time of tissue cryopreservation and with pelvic radiation. Success rates are apparently not reduced after overnight transportation of ovarian tissue before freezing.

STUDY DESIGN, SIZE, DURATION

Registry analysis of 244 transplantations in 196 women, performed by 26 FertiPROTEKT network centres from 2007 to 2019 with follow-up till December 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Orthotopic ovarian tissue transplantations were performed in 196 women, 191 with previous malignant and 5 with previous non-malignant diseases. Size of transplanting centres varied between 1 and 100 transplantations per centre (median: 2). Factors possibly associated with success rate such as female age, first and repeated transplantation, experience of the transplanting centre and overnight transportation of the ovarian tissue before freezing were analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

Average age of all 196 transplanted women was 31.3 years (SD 5.2; range 17-44) at the time of cryopreservation of tissue and 35.9 years (SD 4.8; range 23-47) at the time of transplantation. Pregnancy rate was 30.6% (95% CI, 24.2-37.6%) per first transplantation and 32.7% (95% CI, 26.1-39.7%) per patient. Pregnancy rate was higher after first transplantation (30.6% (95% CI, 24.2-37.6%)) compared to second and subsequent transplantations (11.8% (95% CI, 3.3-27.5%)). Live birth rate per first transplantation was 25.0% (95% CI, 19.1-31.7%) and per patient 26.5% (95% CI, 20.5-33.3%). Success rate decreased with increasing age at the time of ovarian tissue freezing. Live birth rate was 28.2% (95% CI, 20.9-36.3%) in women <35 years and 16.7% (95% CI, 7.9-29.3%) in women >35 years. Pregnancy rates after first transplantation were higher in centres who had performed ≥10 transplantations (35.1%) compared to centres with <10 transplantation (25.4%) (P = 0.12). Corresponding live birth rates were 27.0% and 18.6%. Success rates were not different in women with and without overnight transportation of tissue before cryopreservation.

LIMITATIONS, REASONS FOR CAUTION

The data were drawn from a registry analysis. Data such as ovarian reserve and premature ovarian insufficiency were not available for all women. Data might be influenced by different follow-up policies of the centres.

WIDER IMPLICATIONS OF THE FINDINGS

The study reveals the high potential of ovarian tissue freezing and transplantation, but only if freezing is performed in younger women. The study suggests focus should be placed on the first and not on repeated transplantations. It also opens the discussion of whether transplantation should rather be performed by experienced centres.

STUDY FUNDING/COMPETING INTEREST(S)

No funding. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Laparoscopic ovarian tissue harvesting for cryopreservation from a child with galactosemia

OBJECTIVE

To describe an approach to fertility preservation by a multidisciplinary team of reproductive endocrinology and infertility, pediatric gynecology and surgery, and genetics experts via ovarian tissue harvesting and cryopreservation for a toddler with galactosemia. Galactosemia is associated with progressive primary ovarian insufficiency (POI) and early intervention with ovarian tissue cryopreservation may help preserve fertility.

DESIGN

Video description of a tissue harvesting and cryopreservation technique.

SETTING

Academic institution.

PATIENT(S)

16-month-old female with classic galactosemia.

INTERVENTION(S)

At 6 months of age, despite good metabolic control, the infant's antimüllerian hormone (AMH) level was <0.015 ng/ml; luteinizing hormone level was 3.1 mIU/ml; and follicle stimulating hormone level was 30.2 mIU/ml. She was referred by her geneticist to the reproductive endocrinology and infertility specialist for fertility preservation. The AMH levels and pelvic magnetic resonance imaging findings of the patient were monitored over the next 9 months. Although the magnetic resonance imaging exam showed the presence of a dominant follicle in the right ovary and multiple small antral follicles in both ovaries at the age of 8 months, her laboratory assessment at the age of 14 months suggested impending POI (estradiol level <11.80 pg/mL; LH, 3.3 mIU/ml; follicle stimulating hormone, 35.97 mIU/ml; AMH, 0.03 ng/mL). At 16 months of age, given the low AMH levels, right ovary was laparoscopically harvested, so that a sufficient reserve of primordial follicles may be cryopreserved for fertility preservation. We dissected the mesosalpinx initially to separate the ovary from the tube in a manner that minimized the effects of cauterization on the ovary and preserved the fallopian tube.

MAIN OUTCOME MEASURE(S)

Successful harvesting and cryopreservation of the ovarian tissue containing primordial follicles.

RESULT(S)

The right ovary, which measured 20 × 3 × 3mm, was bisected under a stereomicroscope along the hilum, trimmed to the cortical thickness of 1 mm and sliced into eight 4 × 4-mm pieces. These were then frozen with an established slow freezing protocol. The child was discharged the same day and had an uneventful postoperative course. A subsequent histological examination showed presence of primordial follicles, albeit at a reduced density for her age.

CONCLUSION(S)

Ovarian tissue cryopreservation is feasible in very young female children with rare genetic disorders associated with POI. We illustrated the unique aspects of performing these procedures in very young children.

Investigation of the optimal culture time for warmed bovine ovarian tissues before transplantation

Ovarian tissue cryopreservation by vitrification is an effective technique, but there are still many unresolved issues related to the procedure. The aim of this study was to investigate the optimal culture time of post-warmed ovarian tissues and their viability before ovarian tissue transplantation. The bovine ovarian tissues were used to evaluate the effect of post-warming culture periods (0, 0.25, 0.5, 1, 2, 5 and 24 hours) in the levels of residual cryoprotectant, LDH release, ROS generation, gene and protein abundance, and follicle viability and its mitochondrial membrane potential. Residual cryoprotectant (CPA) concentration decreased significantly after 1 hour of culture. The warmed ovarian tissues that underwent between 0 to 2 hours of culture time showed similar LDH and ROS levels compared to fresh non-frozen tissues. The AMH transcript abundance did not differ in any of the groups. No increase in the relative transcript abundance and protein level of Caspase 3 and Cleaved-Caspase 3, respectively, in the first 2 hours of culture after warming. On the other hand, an increased protein level of double stranded DNA breaks (gamma-H2AX) was observed in post-warmed tissues disregarding the length of culture time, and a temporary reduction in pan-AKT was detected in post-warming tissues between 0 to 0.25 hours of culture time. Prolonged culture time lowered the percentage of viable follicles in warmed tissues, but it did not seem to affect the follicular mitochondrial membrane potential. In conclusion, 1 to 2 hours of culture time would be optimal for vitrified-warmed tissues before transplantation.

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

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

SYSTEMATIC REVIEW REGISTRATION

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