Development of Ovarian Tissue Autograft to Restore Ovarian Function: Protocol for a French Multicenter Cohort Study

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.

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.

Long term pregnancy outcomes of women with cancer following fertility preservation: A systematic review and meta-analysis

OBJECTIVE

As cancer survivorship increases, there is higher uptake of fertility preservation treatments among affected women. However, there is limited evidence on the subsequent use of preserved material and pregnancy outcomes in women who underwent fertility preservation (FP) before cancer treatments. We aimed to systematically review the long-term reproductive and pregnancy outcomes in this cohort of women.

PATIENTS

Women who underwent any type of the following FP treatments: embryo cryopreservation (EC), oocyte cryopreservation (OC) and ovarian tissue cryopreservation (OTC)) before any planned cancer treatment.

EVIDENCE REVIEW

We searched electronic databases (MEDLINE, Embase, Cochrane CENTRAL, and HTA) from inception until May 2021 for all observational studies that met our inclusion criteria. We extracted data on reproductive and pregnancy outcomes in duplicate and assessed the risk of bias in included studies using the ROBINS-I tool. We pooled data using a random-effects model and reported using odds ratios (OR) with 95% confidence intervals (CI).

MAIN OUTCOME MEASURES

Our primary outcome was live birth rate and other important reproductive and pregnancy outcomes.

RESULTS

Of 5405 citations, we screened 103 and included 26 observational studies (n = 7061 women). Hematologic malignancy was the commonest cause for seeking FP treatments, followed by breast and gynecology cancers. Twelve studies reported on OTC (12/26, 46 %), eight included EC (8/26, 30 %), and twelve reported on OC (12/26, 46 %). The cumulative live birth rate following any FP treatment was 0.046 (95 %CI 0.029-0.066). Only 8 % of women returned to use their frozen reproductive material (558/7037, 8.0 %), resulting in 210 live births in total, including assisted conceptions following EC/OC/OTC and natural conceptions following OTC. The odds for live birth was OR 0.38 (95 %CI 0.29-0.48 I² 83.7 %). The odds for live birth was the highest among women who had EC (OR 0.45, 95 %CI 0.14-0.76, I² 95.1 %), followed by the OTC group (OR 0.37, 95 %CI 0.22-0.53, I² 88.7 %) and OC group (OR 0.31, 95 %CI 0.15-0.47, I² 78.2 %).

CONCLUSIONS

Fertility preservation treatments offered good long-term reproductive outcomes for women with cancer with a high chance to achieve a live birth. Further research is needed to evaluate the long-term pregnancy and offspring outcomes in this cohort.

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.

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.

Minimal residual disease detection by multicolor flow cytometry in cryopreserved ovarian tissue from leukemia patients

Background

Cryopreservation of ovarian tissue is a fertility-preservation option for women before gonadotoxic treatments. However, cryopreserved ovarian tissue transplantation must be performed with caution in women with malignancies that may metastasize to the ovaries. For this purpose, detecting minimal residual disease (MRD) in the ovarian cortex using sensitive methods is a crucial step. We developed an automated ovarian tissue dissociation method to obtain ovarian cell suspensions.

Results

We assessed MRD by multicolor flow cytometry (MFC) in cryopreserved ovarian cortex of 15 leukemia patients: 6 with B-cell acute lymphoblastic leukemia (B-ALL), 2 with T-cell acute lymphoblastic leukemia (T-ALL) and 7 with acute myeloid leukemia (AML). Ovarian MRD was positive in 5 of the 15 leukemia patients (one T-ALL and 4 AML). No B-ALL patient was positive by MFC. Quantitative reverse-transcribed polymerase chain reaction was performed when a molecular marker was available, and confirmed the MFC results for 3 patients tested. Xenografts into immunodeficient mice were also performed with ovarian cortical tissue from 10 leukemia patients, with no evidence of leukemic cells after the 6-month grafting period.

Conclusions

In conclusion, this is the first study using MFC to detect MRD in ovarian cortical tissue from acute leukemia patients. MFC has been accepted in clinical practice for its ease of use, the large number of parameters available simultaneously, and high throughput analysis. We demonstrate here that MFC is a reliable method to detect MRD in cryopreserved ovarian tissue, with a view to controlling the oncological risk before ovarian tissue transplantation in leukemia patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00936-4.

In vitro maturation of immature oocytes from ovarian tissue prior to shipment to a cryobank

PURPOSE

Female fertility preservation prior to gonadotoxic therapies can be achieved by the cryopreservation of ovarian cortical tissue. Immature oocytes may be recovered during the preparation, matured in vitro and lead to live births, thereby providing an additional option for fertility preservation. The purpose of this study was to test the feasibility of this approach in a setting with unilateral biopsy of a small piece of ovarian tissue and minimal tissue preparation prior to shipment to an external cryobank.

METHODS

A prospective observational clinical study in an academic center was performed from January 2018 through December 2019. Ovarian tissue was obtained laparoscopically. Immature oocytes were recovered by minimal preparation of the tissue before shipment to an external cryobank for cryopreservation. In vitro maturation was performed on recovered immature oocytes.

RESULTS

Twelve patients were enrolled. Immature oocytes could be recovered for all. The maturation rate was 38.9% (n = 14/36). Metaphase II (MII) were either directly used for intracytoplasmic sperm injection (ICSI) with a fertilization rate of 66.6% (n = 4/6) or vitrified (n = 8). PNs were cryopreserved (n = 4). Vitrified MII were warmed with a post-warming vitality rate of 75.0% (n = 3/4) and used for ICSI with a fertilization rate of 33.3% (n = 1/3).

CONCLUSIONS

Immature oocytes can be successfully retrieved from ovarian tissue through minimal tissue preparation prior to shipment to a cryobank, matured in vitro, fertilized and cryopreserved for potential future fertility treatments. The total number of oocytes available for fertility preservation can be increased even without controlled ovarian stimulation in a situation where only ovarian biopsy for cryopreservation is performed.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS), DRKS00013170. Registered 11 December 2017, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00013170 .

Robot-assisted laparoscopic auto-graft of patchwork ovarian cortex in two steps

The main difficulty of ovarian tissue autograft (OTA) is to preserve as many follicles as possible because the ovarian tissue undergoes warm ischemia during grafting until revascularisation, resulting in significant follicular loss. We describe a two-stage grafting technique to stimulate new vascularisation in order to enhance the revascularization process to reduce the ischemic injuries. Furthermore we performed ovarian patchwork in the laboratory and then grafting with robotic laparoscopy to facilitate surgery and increase precision. This technique is used in the DATOR study with promising results, such as a 40% delivery rate.