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

Pregnancy outcomes following ovarian tissue cryopreservation: an Australian cohort study

BACKGROUND

Ovarian tissue cryopreservation is an increasingly utilized fertility preservation method in young women, with this technique being largely implemented across Europe and Australia. Australia is a pioneer of ovarian tissue cryopreservation, but the clinical perinatal outcomes are currently unknown for the Australian population. These outcomes are important as they contribute to the global understanding of which patients can benefit from this fertility preservation option.

OBJECTIVE

To examine the pregnancy and mortality outcomes of patients who have undergone ovarian tissue cryopreservation and/or ovarian tissue transplantation in Victoria, Australia, and investigate predictors of success.

STUDY DESIGN

A retrospective cohort study was conducted including patients who underwent ovarian tissue cryopreservation from July 1995-July 2022 at the largest ovarian tissue cryopreservation center in Victoria, Australia. Patients over the age of 18 at the time of the study were included in the study. Perinatal and mortality data were obtained through data linkage from the Victorian Perinatal Data Collection and Births Deaths and Marriages databases.

RESULTS

Overall, 593 patients had undergone ovarian tissue cryopreservation between July 1995 and July 2022 in Victoria, Australia. All 593 patients were successfully linked to the perinatal and mortality databases, of whom 6 (1.0%) had pregnancies lacking perinatal data, and 17 had mortality data not reflected in the linkage but next of kin reported their deaths to the ovarian tissue cryopreservation providing clinic. Of this cohort, 48 (8.1%) underwent ovarian tissue transplantation and 106 (17.9%) died from complications of their medical indication for tissue freezing. A total of 192 neonates from 114 women were reported from both transplant (n=12/48, 25.0%) and nontransplant (n=102/545, 18.7%) cohorts. Most women had reported pregnancies by 15 years after ovarian tissue cryopreservation, with transplant cases having a similar overall pregnancy rate as per the time-to-event analysis (adjusted subdistribution hazard ratio 1.378, 95% confidence interval 0.755-2.515, P=.296).

CONCLUSION

This is a large single-center cohort study within the southern hemisphere that investigates patients who have undergone ovarian tissue cryopreservation, with one in 5 women achieving a pregnancy, emphasizing the clinical feasibility of ovarian tissue cryopreservation as a fertility preservation option for future fertility counseling.

Standardization for ovarian tissue cryopreservation and transplantation in China

Ovarian tissue cryopreservation and transplantation is one of the most advanced and promising fertility preservation methods. Prior to any procedure that may lead to a toxic ovarian injury (such as chemotherapy or radiotherapy), a portion of the ovary is removed and cryopreserved. At an appropriate time, after toxic therapy is concluded, the cryopreserved ovarian tissue is then thawed and transplanted back to the patient when conditions permit. This technique can not only preserve female fertility but also restore ovarian endocrine function. However, there is no standardization for ovarian tissue cryopreservation and transplantation in China. In order to promote the standardized development of ovarian tissue cryopreservation technology in the whole country, it is urgent to establish the standard of this technology.

Premature ovarian insufficiency

Premature ovarian insufficiency (POI) is a cause of infertility and endocrine dysfunction in women, defined by loss of normal, predictable ovarian activity before the age of 40 years. POI is clinically characterized by amenorrhoea (primary or secondary) with raised circulating levels of follicle-stimulating hormone. This condition can occur due to medical interventions such as ovarian surgery or cytotoxic cancer therapy, metabolic and lysosomal storage diseases, infections, chromosomal anomalies and autoimmune diseases. At least 1 in 100 women is affected by POI, including 1 in 1,000 before the age of 30 years. Substantial evidence suggests a genetic basis to POI. However, the cause of idiopathic POI remains unknown in most patients, indicating that gene variants associated with this condition remain to be discovered. Over the past 10 years, tremendous progress has been made in our knowledge of genes involved in POI. Genetic approaches in diagnosis are important as they enable patients with familial POI to be identified, with the opportunity for oocyte preservation. Moreover, genetic approaches could provide a better understanding of disease mechanisms, which will ultimately aid the development of improved treatments.

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.

A 12-year overview of fertility preservation practice in Nordic pediatric oncology centers

PURPOSE

Fertility preservation is the only option to safeguard fertility following gonadotoxic treatments. This study aimed to provide an updated status on fertility preservation for pediatric cancer patients in the Nordic countries.

METHODS

A questionnaire consisting of 14 questions was sent to directors of 18 main pediatric oncology centers in the Nordic countries in 2010 and 2022. We received information regarding indications, guidelines, counseling, and available fertility preservation options.

RESULTS

The response rates were 89% in 2010 and 72% in 2022. The results reveal an increase in clinical practice guidelines on fertility preservation for cancer patients, from 25% in 2010 to 70% in 2022. Counseling on fertility preservation options in 2022 was more specific and offered to most patients who fulfilled indications for fertility preservation (from 19 to 77%). Sperm cryopreservation continues to be the predominant fertility preservation method for pubertal boys in the Nordic countries. However, there has been a notable increase in the availability of testicular tissue preservation for prepubertal boys (0 to 62%). A similar increase in the offer of ovarian tissue preservation for prepubertal girls (0 to 92%) was observed among pediatric cancer patients.

CONCLUSIONS

The past decade has shown commendable advancements in fertility preservation for pediatric cancer patients in the Nordic countries.

IMPLICATIONS FOR CANCER SURVIVORS

As fertility care evolves globally, continuous assessment of regional practices and challenges is imperative to enhance the quality of care and life for pediatric cancer survivors in the Nordic regions.

Ovarian tissue transplantation: 10 years of experience at the Bologna University

Objective

The efficiency of ovarian tissue transplantation (OTT) was established in terms of ovarian function recovery (95% of cases), number of live births (over 200 worldwide to date) and induction of puberty. Unfortunately, the lack of international registries and the fact that many centers have not yet reported their outcomes, lead to poor knowledge of the exact fertility data. The aim of the study is to describe our experience with OTT to restore ovarian function and fertility.

Methods

This study was designed as a single-center, observational, retrospective, cohort study that includes women who underwent OTT between December 2012 and June 2023 at our center. After approval by the oncologist/hematologist, a small fragment of ovarian tissue was thawed and analyzed to detect the presence of micrometastases before OTT. Thawed ovarian tissue was grafted laparoscopically at multiple sites, including the remaining ovary and pelvic side wall (orthotopic transplantation) and/or abdominal wall (heterotopic transplantation). After OTT, ovarian function was monitored by hormonal assay, ultrasound and color Doppler at approximately 4-week intervals.

Results

Between December 2012 and June 2023, 30 women performed OTT. Prior to OTT, immunohistochemical and molecular analyses revealed no micrometastases in all thawed ovarian tissue samples. In our series of 30 women, 20 of women were on premature ovarian insufficiency (POI), and the remaining ten cases still had oligomenorrhea and difficulty getting pregnant. Among the women with POI before OTT and at least 6 months follow-up, recovery of endocrine function was observed in all but one woman who underwent orthotopic transplantation (13 of 14 cases), in one out of two women who underwent both orthotopic and heterotopic transplantation (1 of 2 cases) and in all women who underwent heterotopic transplantation (4 of 4 cases). Women who underwent OTT to enhance fertility had no alterations in menstrual cycle and hormonal levels. In total, ten pregnancies were obtained in 25 women, resulting in four live births, two ongoing pregnancies and four spontaneous abortions.

Conclusion

Our data can help patients and physicians in their discussions and decisions about the need and possibilities of preserving fertility.