Time to consider ovarian tissue cryopreservation for girls with Turner's syndrome: an opinion paper

Should Ovarian Tissue Cryopreservation in Pediatric Patients with Turner Syndrome Be Limited to the Research Setting?

Now that ovarian tissue cryopreservation (OTC) has become standard of care for patients receiving gonadotoxic therapies, discussion has turned toward offering OTC to pediatric patients with Turner syndrome outside of research. Although patients with Turner syndrome have unmet fertility needs and the authors support efforts for fertility preservation in these individuals, safety and efficacy data about OTC in this population are limited. Building on longstanding debates around offering experimental therapies as research or outside of research (as "innovative therapy"), we considered the suitability of offering OTC for patients with Turner syndrome as innovative therapy. On the basis of pathophysiology and preliminary research data, we argue that there is significant uncertainty about whether the risk-benefit profile of OTC for patients with Turner syndrome is favorable. This reduces the weight of arguments in favor of offering it as innovative therapy. Furthermore, as Turner syndrome is rare, widespread availability of OTC could make it difficult to develop generalizable knowledge. The benefits of innovative therapy for acquiring experience from use in humans and avoiding research-related procedures are of limited importance too, as OTC is already an established procedure, and current studies involve limited procedures that restrict access. OTC should therefore only be offered to patients with Turner syndrome in research settings until additional data suggest that the risk-benefit profile is likely favorable.

Should we perform oocyte accumulation to preserve fertility in women with Turner syndrome? A multicenter study and systematic review of the literature

STUDY QUESTION

Should we perform oocyte accumulation to preserve fertility in women with Turner syndrome (TS)?

SUMMARY ANSWER

The oocyte cryopreservation strategy is not well adapted for all TS women as their combination of high basal FSH with low basal AMH and low percentage of 46,XX cells in the karyotype significantly reduces the chances of freezing sufficient mature oocytes for fertility preservation.

WHAT IS KNOWN ALREADY

An oocyte cryopreservation strategy requiring numerous stimulation cycles is needed to preserve fertility in TS women, to compensate for the low ovarian response, the possible oocyte genetic alterations, the reduced endometrial receptivity, and the increased rate of miscarriage, observed in this specific population. The validation of reliable predictive biomarkers of ovarian response to hormonal stimulation in TS patients is necessary to help practitioners and patients choose the best-personalized fertility preservation strategy.

STUDY DESIGN, SIZE, DURATION

A retrospective bicentric study was performed from 1 January 2011 to 1 January 2023. Clinical and biological data from all TS women who have received from ovarian stimulation for fertility preservation were collected. A systematic review of the current literature on oocyte retrieval outcomes after ovarian stimulation in TS women was also performed (PROSPERO registration number: CRD42022362352).

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 14 TS women who had undergone ovarian stimulation for fertility preservation were included, representing the largest cohort of TS patients published to date (n = 14 patients, 24 cycles). The systematic review of the literature identified 34 additional TS patients with 47 oocyte retrieval outcomes after ovarian stimulation in 14 publications (n = 48 patients, n = 71 cycles in total).

MAIN RESULTS AND THE ROLE OF CHANCE

The number of cryopreserved mature oocytes on the first cycle for TS patients was low (4.0 ± 3.7). Oocyte accumulation was systematically proposed to increase fertility potential and was accepted by 50% (7/14) of patients (2.4 ± 0.5 cycles), leading to an improved total number of 10.9 ± 7.2 cryopreserved mature oocytes per patient. In the group who refused the oocyte accumulation strategy, only one patient exceeded the threshold of 10 mature cryopreserved oocytes. In contrast, 57.1% (4/7) and 42.9% (3/7) of patients who have underwent the oocyte accumulation strategy reached the threshold of 10 and 15 mature cryopreserved oocytes, respectively (OR = 8 (0.6; 107.0), P = 0.12; OR= 11 (0.5; 282.1), P = 0.13). By analyzing all the data published to date and combining it with our data (n = 48 patients, n = 71 cycles), low basal FSH and high AMH concentrations as well as a higher percentage of 46,XX cells in the karyotype were significantly associated with a higher number of cryopreserved oocytes after the first cycle. Moreover, the combination of low basal FSH concentration (<5.9 IU/l), high AMH concentration (>1.13 ng/ml), and the presence of 46,XX cells (>1%) was significantly predictive of obtaining at least six cryopreserved oocytes in the first cycle, representing objective criteria for identifying patients with real chances of preserving an adequate fertility potential by oocyte cryopreservation.

LIMITATIONS, REASONS FOR CAUTION

Our results should be analyzed with caution, as the optimal oocyte number needed for successful live birth in TS patients is still unknown due to the low number of reports their oocyte use in the literature to date.

WIDER IMPLICATIONS OF THE FINDINGS

TS patients should benefit from relevant clinical evaluation, genetic counseling and psychological support to make an informed choice regarding their fertility preservation technique, as numerous stimulation cycles would be necessary to preserve a high number of oocytes.

STUDY FUNDING/COMPETING INTEREST(S)

This research received no external funding. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Evaluation of ovarian reserve in young females with non-iatrogenic ovarian insufficiency to establish criteria for ovarian tissue cryopreservation

RESEARCH QUESTION

Can ovarian reserve parameters predict the outcome of ovarian tissue cryopreservation (OTCP) in patients ≤18 years with non-iatrogenic premature ovarian insufficiency (POI)?

DESIGN

Retrospective cohort analysis carried out in a single tertiary hospital between August 2010 and January 2020. Thirty-seven patients ≤18 years with non-iatrogenic POI (27 with Turner syndrome, six with POI of unknown aetiology, three with galactosemia and one with blepharophimosis, ptosis, epicanthus inversus syndrome) were included. Three parameters were used to evaluate ovarian reserve: anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH) and transabdominal antral follicle count. Fertility preservation (most commonly OTCP) was offered if ovarian reserve was diminished and one or more parameters was positive. Follicles were counted in ovarian samples obtained at the time of OTCP.

RESULTS

Ovarian reserve was diminished in 34 patients and 19 of them had one or more positive parameter. Fourteen (11 aged ≥12 years and 3 aged <12) underwent OTCP, one (14 years old) underwent ovarian stimulation and oocyte cryopreservation and four declined fertility preservation. Follicles were detected in 11 of 14 patients who underwent OTCP with one or more positive parameters (79%), and in all those (100%) who had two or three positive parameters. The median number of follicles was 27 (range 5-64) and 48 (range 21-75) in patients ≥12 years and those <12 years, respectively.

CONCLUSION

This study shows that if OTCP is performed in patients with one or more positive parameters of ovarian activity, a 79% positive predictive value is achieved for the detection of follicles. The incorporation of this criterion for OTCP will minimize the risk of harvesting ovarian tissue with a low number of follicles.

Trends and outcomes of fertility preservation for girls, adolescents and young adults with Turner syndrome: A prospective cohort study

BACKGROUND

In Scandinavian countries, programs for fertility preservation (FP) are offered free of charge at tertiary-care university hospitals to all patients facing infertility risks due to malignant diagnoses or benign conditions. In this prospective study we aimed to investigate trends and outcomes of FP indicated by a diagnosis of Turner syndrome.

METHODS

Prospective cohort study of patients with Turner karyotype receiving fertility preservation counselling at the Karolinska University Hospital between 1 January 1999 and 31 December 2021.

RESULTS

The cohort included 100 women and girls that received counselling, whereof 27% were prepubertal girls, 59% were adolescents and 14% of adult age. Before 2006 all patients were referred for fertility counselling at the time of Turner diagnosis. Based on updated guidelines, mainly patients who showed signs of puberty were referred after 2006. As a result, spontaneous menarche was more common in the later period. In total, 39% of the cohort had monosomal karyotype (45X), 20% had 45X/46XX or 45X/47XXX mosaicisms and 36% had an X-chromosomal structural anomaly. Ovarian tissue cryopreservation was planned for 73% of all patients, and oocyte cryopreservation following gonadotropin stimulation was planned for 10% of the patients. Follicles were present in 25% of all biopsies analyzed. Adolescents were more likely to have follicles present (30%) than prepubertal girls (16%) or adult women (17%). The ten patients that underwent gonadotropin stimulation for oocyte cryopreservation underwent a total of 15 cycles and eight patients successfully preserved oocytes. In total, 26% of the cohort has undergone fertility treatment or expressed further interest in fertility preservation. Six women have given birth using donated oocytes and three following spontaneous conception. Two women have undergone re-transplantation of cryopreserved ovarian tissue, without regaining ovarian function, and none of the women that have cryopreserved oocytes has returned to use them.

CONCLUSION

Fertility counselling for girls with Turner syndrome should ideally be offered at onset of spontaneous puberty to improve the chances of fertility preservation. Since the girls and women in this cohort are still young, the return rate and utilization of the preserved tissue and oocytes is expected to increase with time.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NTC04602962.

Ovarian Reserve Disorders, Can We Prevent Them? A Review

The ovarian reserve is finite and begins declining from its peak at mid-gestation until only residual follicles remain as women approach menopause. Reduced ovarian reserve, or its extreme form, premature ovarian insufficiency, stems from multiple factors, including developmental, genetic, environmental exposures, autoimmune disease, or medical/surgical treatment. In many cases, the cause remains unknown and resulting infertility is not ultimately addressed by assisted reproductive technologies. Deciphering the mechanisms that underlie disorders of ovarian reserve could improve the outcomes for patients struggling with infertility, but these disorders are diverse and can be categorized in multiple ways. In this review, we will explore the topic from a perspective that emphasizes the prevention or mitigation of ovarian damage. The most desirable mode of fertoprotection is primary prevention (intervening before ablative influence occurs), as identifying toxic influences and deciphering the mechanisms by which they exert their effect can reduce or eliminate exposure and damage. Secondary prevention in the form of screening is not recommended broadly. Nevertheless, in some instances where a known genetic background exists in discrete families, screening is advised. As part of prenatal care, screening panels include some genetic diseases that can lead to infertility or subfertility. In these patients, early diagnosis could enable fertility preservation or changes in family-building plans. Finally, Tertiary Prevention (managing disease post-diagnosis) is critical. Reduced ovarian reserve has a major influence on physiology beyond fertility, including delayed/absent puberty or premature menopause. In these instances, proper diagnosis and medical therapy can reduce adverse effects. Here, we elaborate on these modes of prevention as well as proposed mechanisms that underlie ovarian reserve disorders.

Parenthood among individuals with Turner syndrome: results of an online survey of attitudes towards pregnancy, adoption, and surrogacy

Choosing a route to parenthood can be a difficult decision for individuals with Turner syndrome, who must consider the unlikely possibility of spontaneous pregnancy, the potential need for assisted reproductive technology such as in vitro fertilization (IVF), and the risks of pregnancy-related complications. In addition, there are other options for parenthood, such as surrogacy and adoption. The perspectives of individuals with Turner syndrome regarding routes to parenthood have not been described in the literature, despite thorough investigation into the feasibility and safety of pregnancy in this population. We conducted a novel online survey of 226 individuals with Turner syndrome to assess their interest in parenthood, their perspectives on available routes to parenthood, and the factors that influence their decision-making. One-quarter of the respondents were already parents, including 54.5% who had achieved pregnancy and 45.5% who adopted. Of those who were not parents, 68.5% expressed a desire to become a parent. Overall, participants had the strongest interest in adoption as a route to parenthood. Interest in adoption was significantly associated with fear of pregnancy-related risks to their health and the health of a future child. Participants also reported interest in pregnancy and IVF. Interest in both pregnancy and IVF were significantly associated with a desire to experience pregnancy and to have a biological child. This study provides important insights into the perspective of individuals with Turner syndrome with respect to building a family and serves as a valuable counseling resource for clinicians facilitating patient decision-making about options for parenthood.

Ageing and chronic disease-related changes in the morphometric characteristics of ovarian follicles in cynomolgus monkeys (Macaca fascicularis)

STUDY QUESTION

How is the localisation of ovarian follicles affected by ageing and chronic diseases?

SUMMARY ANSWER

Ovarian follicles shift deeper towards the medulla, due to thickening of the tunica albuginea (TA), with ageing and some major common chronic diseases.

WHAT IS KNOWN ALREADY

The ovary undergoes morphological and functional changes with ageing. The follicular pool follows these changes with alterations in the amount and distribution of residual follicles. Diseases causing a chronic inflammatory process are associated with morphological changes and impaired ovarian function.

STUDY DESIGN, SIZE, DURATION

We conducted a cross-sectional study, examining 90 ovaries from 90 female monkeys. The samples were collected from April 2018 to March 2019 at Tsukuba Primate Research Center in National Institutes of Biomedical Innovation, Health and Nutrition, Japan.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovarian samples were obtained from cynomolgus monkeys that died from natural causes or were euthanised. Ovarian sections were stained with haematoxylin and eosin (H&E) for histological analyses. In ovarian sections from 64 female macaques aged 0-25 years, a total of 13 743 follicles at different developmental stages (primordial, intermediary, primary, early secondary and late secondary) were assessed to determine the depth of each follicle from the outer surface of the ovarian cortex to the far end of the follicle, by using a digital imaging software. TA thickness was measured as sum of basal membrane and tunica collagen layer for each ovary under H&E staining. To explore the possibility of age-related trends in ovarian morphometric characteristics, samples were divided into four different age groups (0-3 years (pre-menarche), 4-9 years, 10-14 years and 15-20 years). To evaluate the effect of common chronic diseases on ovarian morphometric characteristics, macaques with diabetes mellitus (DM) (n = 10), endometriosis (n = 8) or inflammatory bowel disease (IBD) (n = 8) were compared to age-matched controls without chronic diseases.

MAIN RESULTS AND THE ROLE OF CHANCE

Ovarian morphometric analysis revealed that the relative location of follicles became deeper in all age groups according to development of follicles (P < 0.05). Total follicle distance from the ovarian surface was increased with ageing (P < 0.05). In a sub-analysis according to developmental stage, only primordial and intermediary follicles were localised deeper with increasing age (P < 0.05). TA thickness was also increased with ageing (P < 0.05). The localisation of the total number of follicles became deeper in ovaries from monkeys with DM, endometriosis or IBD as compared to the control group (P < 0.05). With DM, analysis of follicles distance at almost each developmental stage was significantly deeper compared to controls (P < 0.05) with the exception of early secondary follicles. With endometriosis, follicles at primary and early and late secondary stages were significantly deeper compared to controls (P < 0.05). Also with IBD, follicles at primary and early and late secondary follicles were significantly deeper compared to controls (P < 0.001). The TA was thicker with DM and endometriosis compared to controls (P < 0.05), but not with IBD (P = 0.16).

LARGE SCALE DATA

NA.

LIMITATIONS, REASONS FOR CAUTION

Two-dimensional histology was used to assess follicle localisation. The possibility of minimal variations between the measured distance to the actual distance in a spherical structure cannot be excluded. Additionally, the severity of disease was not assessed.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first step towards enhancing our understanding of how ageing and chronic diseases affect the relative localisation of dormant and developing follicles. These observations, combined with possible future human studies, may have managerial implications in the field of fertility preservation and other conditions involving ovarian tissue cryopreservation.

STUDY FUNDING/COMPETING INTEREST(S)

The present work was supported by the Grant-in-Aid for Scientific Research B (19H03801) (to K.K.), Challenging Exploratory Research (18K19624), Japan Agency for Medical Research and Development, Mochida Memorial Foundation for Medical and Pharmaceutical Research, Takeda Science Foundation and Naito Foundation (to K.K.). All authors have no conflicts of interest directly relevant to the content of this article.

Can frozen-thawed human ovary withstand refreezing-rethawing in the form of cortical strips?

PURPOSE

The aim of this study was to elucidate whether ovarian tissue is able to withstand a double freezing-thawing procedure.

METHODS

Human ovarian cortical biopsies from 4 thawed whole ovaries were divided into 4 experimental subgroups: (a) frozen-thawed non-grafted group, (b) frozen-thawed xenografted group, (c) refrozen-rethawed non-grafted group, and (d) refrozen-rethawed xenografted group. Xenografting was performed using 8 severe combined immunodeficient mice for a total duration of 21 days. The following analyses were conducted: classic hematoxylin and eosin staining, Ki67 immunolabeling, transmission electron microscopy, Masson's green trichrome, and double CD34 immunostaining.

RESULTS

Morphologically normal preantral follicles were detected in all groups. We observed a dramatic decline of more than 65% in early preantral follicle survival rates after grafting of both frozen-thawed (p < 0.0001) and refrozen-rethawed (p < 0.0001) ovarian tissue. However, mean follicle densities remained comparable between the frozen-thawed and refrozen-rethawed non-grafted groups, as well as both grafted groups. Equivalent proportions of proliferating early preantral follicles were identified in frozen-thawed and refrozen-rethawed samples, whether the tissue was grafted or not. Furthermore, we did not observe any significant difference in atretic follicle rates between any of the four groups, and the ultrastructural quality of follicles appeared unaffected by the refreezing procedure. Similar proportions of fibrosis were noted in the frozen-thawed and refrozen-rethawed groups, irrespective of grafting. Finally, no significant differences were witnessed in terms of vascularization.

CONCLUSION

We were able to demonstrate, for the first time, that refrozen-rethawed ovarian tissue has the same functional characteristics as frozen-thawed ovarian tissue.

Human Ovarian Cortex biobanking: A Fascinating Resource for Fertility Preservation in Cancer

Novel anti-cancer treatments have improved the survival rates of female young patients, reopening pregnancy issues for female cancer survivors affected by the tumor treatment-related infertility. This condition occurs in approximately one third of women of fertile age and is mainly dependent on gonadotoxic protocols, including radiation treatments. Besides routine procedures such as the hormonal induction of follicular growth and subsequent cryopreservation of oocytes or embryos, the ovarian protection by gonadotropin-releasing hormone (GnRH) agonists during chemotherapy as well as even gonadal shielding during radiotherapy, other innovative techniques are available today and need to be optimized to support their introduction into the clinical practice. These novel methods are hormone stimulation-free and include the ovarian cortex cryopreservation before anti-cancer treatments and its subsequent autologous reimplantation and a regenerative medicine approach using oocytes derived in vitro from ovarian stem cells (OSCs). For both procedures, the major benefit is related to the prompt recruitment and processing of the ovarian cortex fragments before gonadotoxic treatments. However, while the functional competence of oocytes within the cryopreserved cortex is not assessable, the in vitro maturation of OSCs to oocytes, allows to select the most competent eggs to be cryopreserved for fertility restoration.

The safety and satisfaction of ovarian tissue cryopreservation in prepubertal and adolescent girls

RESEARCH QUESTION

Is ovarian tissue cryopreservation (OTC) for fertility preservation in prepubertal and adolescent girls safe, and who would benefit most from the procedure?

DESIGN

Survey and retrospective study including patients who had OTC under the age of 18 years in a single centre for fertility preservation. Serum anti-Müllerian hormone levels were measured as a marker for detection of diminished ovarian reserve.

RESULTS

Fifty-three from 102 women participated in the survey (12 deceased, 19 declined, 17 unreachable, 1 palliative). The average age at OTC was 14.8 ± 2.3 (range: 6-17) years and at survey 21.9 ± 4.3 (range: 16-33) years. Ovarian tissue retrieval (laparoscopy: n = 45, laparotomy: n = 8) was without complications in 52 cases. In 23 (53.5%) of the 43 women who were post-menarchal at OTC, transient amenorrhoea occurred. At survey, 15 women reported a regular menstrual cycle, 25 used oral contraceptives, 9 women reported hormone replacement therapy due to primary ovary insufficiency and 4 had amenorrhoea. Two patients reported the birth of a healthy child after IVF, while 51 patients are still childless, mostly due to their young age (mean: 21.2 years). To date, one patient has had transplantation of the ovarian tissue (17 years at cryopreservation). Forty-nine of the interviewees would again decide on OTC, while three argued against it on the basis of the previous financial cost; one woman was unsure.

CONCLUSIONS

Children with cancer may be at risk for gonadal insufficiency. OTC is practically the only technique that can be offered to young girls. The procedure is safe and well accepted.