Ovarian follicles of young patients with Turner's syndrome contain normal oocytes but monosomic 45,X granulosa cells

Turner syndrome: the promise of fertility via stem cell technology

Turner syndrome (TS) is the most common female sex chromosome disorder, occurring in one out of every 2500 to 3000 live female births. It is caused by the partial or complete loss of one X chromosome. TS is associated with certain physical and medical features, including short stature, estrogen deficiency, delayed puberty, hypothyroidism, and congenital heart defects. The majority of women with TS are infertile as a result of gonadal dysgenesis and primary ovarian insufficiency causing hypergonadotropic hypogonadism. Several reproductive options are available for TS patients. The recent use of stem cells (SCs) was found to constitute a promising new alternative in cases of infertility treatment in this group. SCs are undifferentiated cells that exist in embryos, fetuses, and adults and that produce differentiated cells. They can be used in infertility treatment for ovarian regeneration and oocyte generation. However, additional studies scrutinizing their efficiency and safety are needed. In our review, we present reproductive options that are currently available for women with TS.

Gene expression analysis of ovarian follicles and stromal cells in girls with Turner syndrome

In patients with mosaic Turner syndrome, the ovarian somatic cells (granulosa and stromal cells) display a high level of aneuploidy with a 45,X karyotype, which may affect gene expression in the ovary and contribute to their reduced fertility. The aim of the current research is to study the effect of aneuploidy of somatic ovarian cells on gene expression in ovarian cortex stromal cells and small ovarian follicles from mosaic (45,X/46,XX) Turner syndrome patients. To this end, ovarian cortical tissue was obtained by laparoscopic surgery from eight mosaic Turner syndrome patients (aged 5-19 years) and eight controls (aged 6-18 years). The tissue was fractionated to obtain purified follicles and stromal cells. Part of the purified fractions was used to determine the X chromosomal content of ovarian cells of Turner syndrome patients by interphase FISH, while the remaining part was used to compare the gene expression profile of these cells to controls. The results demonstrated that high level 45,X haploidy in cortical stromal cells of Turner syndrome patients had no effect on gene expression, gross morphology of the ovary, or histological appearance of the cortex compared to controls. Gene expression analysis of purified small follicles of Turner syndrome patients with mainly 45,X granulosa cells revealed aberrant expression of 11 genes. Of these, six were upregulated (CD24, TLR1, EPHA2, PLXND1, ST6GALNAC5, and NOX4) while five genes (CRYAB, DLX1, PCYT2, TNFRSF8, and CA12) were downregulated compared to follicles of controls. Interestingly, the overexpressed genes in these small follicles were all associated with more advanced stages of follicular development. The consequences of this abnormal gene expression in follicles for Turner syndrome patients remain to be investigated, but they are likely to affect fertility.

Searching for the 'X' factor: investigating the genetics of primary ovarian insufficiency

Primary ovarian insufficiency (POI) is the cessation of ovarian function before the age of 40. The causes of POI are heterogeneous, but substantial evidence exists to support a genetic basis of POI, particularly in the critical involvement of genes on the X chromosome. Recent studies have revealed novel candidate genes through the identification of copy number variations associated with POI. This review summarizes the genes located on the X chromosome with variants shown to be associated with POI in humans and/or in mice. Additionally, we present evidence to support the potential involvement of these candidate genes in the etiology of POI. We conducted a literature search in PubMed to identify case studies and screenings for the genetic causes of POI. We then performed systematic searches for the proposed candidate genes to investigate their potential reproductive roles. Of the X-linked candidate genes investigated, 10 were found to have variants associated with cases of POI in humans. An additional 10 genes were found to play a supportive role in POI. Other genes were not implicated in any cases of POI but were associated with various roles in reproduction. In the majority of cases where variants were identified through whole-exome sequencing, rather than targeted screening of candidate genes, more than one genetic variant was identified. Overall, this review supports past findings that the X chromosome plays a critical role in ovarian function, as demonstrated by a link between POI and various disruptions to genes on the X chromosome. Current genetic screening for POI, which includes only FMR1, is inadequate to capture the majority of cases with a genetic origin. An expanded genetic testing may improve health outcomes for individuals with POI as it could lead to better early interventions and education about these health risks.

Identification of apelin/APJ signaling dysregulation in a human iPSC-derived granulosa cell model of Turner syndrome

The interaction between germ cells and somatic cells in the ovaries plays a crucial role in establishing the follicle reserve in mammals. Turner syndrome (TS) predominantly affects females who have a partial or complete loss of one X chromosome. Our understanding of the role that granulosa cells (GCs) play in TS disease progression and pathogenesis remains limited. In this study, we achieved GC differentiation efficiency of up to 80% from iPSCs. When attempting to replicate the differentiation process of embryonic granulosa cells, we observed the downregulation of specific genes-GATA4, FOXL2, AMHR2, CYP19A1, and FSH-in Turner syndrome-derived granulosa cells (TS-GCs). Additionally, we identified dysregulation of the cell cycle in TS-GCs. To uncover the endogenous defects in TS-GCs, we compared global transcriptome patterns between iPSC-derived granulosa cells from healthy individuals and those with Turner syndrome. The apelin/APJ pathway exhibited differential signaling between the healthy and TS groups. Supplementation with apelin ligands and activation of apelin/APJ downstream signaling via Akt/PKB restored cell cycle progression and marker gene expression. We hypothesize that during early embryonic development, failures in apelin/APJ signaling in GCs of Turner syndrome patients lead to abnormalities in ovarian development, ultimately resulting in early oocyte loss and infertility.

Puberty progression in girls with Turner syndrome after ovarian tissue cryopreservation

OBJECTIVE

To study the impact of unilateral ovariectomy for ovarian tissue cryopreservation (OTC) on the function of the remaining ovary in girls with Turner syndrome.

DESIGN

A prospective cohort study as a follow-up of OTC in a research setting (the TurnerFertility trial, NCT03381300).

SETTING

University Hospital.

PATIENT(S)

A total of 28 girls with Turner syndrome with follicles in their cryopreserved ovarian cortex tissue, aged 5-19 years. Of the 28 girls, 21 had a 45,X/46,XX mosaic karyotype; 5 had structural aberrations of the X chromosome; 1 had a 45,X monosomy; and 1 had a 45,X/47,XXX karyotype.

INTERVENTION(S)

Girls were monitored annually after OTC for pubertal development and levels of antimüllerian hormone (AMH), follicle-stimulating hormone, luteinizing hormone, estradiol, and inhibin B.

MAIN OUTCOME MEASURE(S)

Thelarche, menarche, and onset of premature ovarian insufficiency.

RESULT(S)

The girls were monitored for a median duration of 3.4 years (maximum 6.6 years). The pubertal development of five prepubertal girls is still unknown; all were aged <10 years and had low gonadotropin and estradiol levels at the end of the follow-up. Seven of the eight girls of approximately pubertal age (10-12 years) experienced spontaneous thelarche, although one received medication to induce puberty. Eleven of the 14 girls between the ages of 14-17 years experienced spontaneous menarche; three other girls with thelarche still had ongoing puberty at the end of follow-up with normal gonadotropins and AMH levels above the detection limit. Approximately 6-12 months after OTC, a decline in AMH concentration was observed in 57% (16/28) of girls, followed by an increase in AMH concentration in the following years. Six of the total 28 girls started hormone replacement therapy because of symptoms of premature ovarian insufficiency, and all had AMH levels <0.50 μg/L before OTC.

CONCLUSION(S)

Pubertal development progressed after unilateral ovariectomy for OTC in most girls with Turner syndrome. Hormone replacement therapy was required within a few years for girls with unfavorable parameters before OTC, such as AMH levels <0.50 μg/L. Decisions regarding OTC should be personalized, considering the girl's preferences and specific characteristics.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03381300-Preservation of ovarian cortex tissue in girls with Turner syndrome-Full Text View-ClinicalTrials.gov. Registered on: December 21, 2017. The first patient was recruited on January 1, 2018.

Navigating fertility dilemmas across the lifespan in girls with Turner syndrome-a scoping review

BACKGROUND

Girls with Turner syndrome (TS) lack a partial or complete sex chromosome, which causes an accelerated decline of their ovarian reserve. Girls have to deal with several dilemmas related to their fertility, while only a limited number of them are referred to a fertility specialist and counselled about options of family planning on time.

OBJECTIVE AND RATIONALE

This scoping review provides an update of the literature on fertility in girls with TS throughout their lifespan and aims to propose a clinical practice guideline on fertility in TS.

SEARCH METHODS

Databases of PubMed, Embase, and Web of science were searched using the following key terms: Turner syndrome, fertility, puberty, pregnancy, sex-hormones, karyotype, fertility preservation, assisted reproductive techniques, and counselling, alongside relevant subject headings and synonymous terms. English language articles published since 2007 were critically reviewed. Pregnancies after using donated oocytes and data about girls with TS with Y-chromosomal content were excluded.

OUTCOMES

This search identified 1269 studies of which 120 were extracted for the review. The prevalence of natural conception ranged from 15% to 48% in women with 45,X/46,XX, 1% to 3% in women with 45,X, and 4% to 9% in women with other TS karyotypes. When assessing a girl's fertility potential, it was crucial to determine the karyotype in two cell lines, because hidden mosaicism may exist. In addition to karyotype, assessment of anti-Müllerian hormone (AMH) played a significant role in estimating ovarian function. Girls with AMH above the detection limit were most likely to experience spontaneous thelarche, menarche, and ongoing ovarian function during the reproductive lifespan. Fertility preservation became more routine practice: vitrification of oocytes was reported in 58 girls with TS and a median of five oocytes were preserved per stimulation. Ovarian tissue cryopreservation has demonstrated the presence of follicles in approximately 30% of girls with TS, mostly in girls with mosaic-TS, spontaneous puberty, and AMH above the detection limit. Although girls and their parents appreciated receiving counselling on fertility in TS, only one in ten girls with TS received specialized counselling. Unfamiliarity with fertility preservation techniques or uncertainties regarding the eligibility of a girl for fertility preservation constituted barriers for healthcare professionals when discussing fertility with girls with TS.

WIDER IMPLICATIONS

There currently is a high demand for fertility preservation techniques in girls with TS. A reliable prognostic model to determine which girls with TS might benefit from fertility preservation is lacking. Only a minority of these girls received comprehensive fertility counselling on the full spectrum of fertility, including uncertainties of fertility preservation, pregnancy risks, and alternatives, such as adoption. Fertility preservation could be a viable option for girls with TS. However, the question remains whether enough oocytes can be obtained for a realistic prospect of a live birth. It is important that girls and parents are empowered with the necessary information to make a well-informed decision.

Clinical practice guidelines for the care of girls and women with Turner syndrome

Turner syndrome (TS) affects 50 per 100 000 females. TS affects multiple organs through all stages of life, necessitating multidisciplinary care. This guideline extends previous ones and includes important new advances, within diagnostics and genetics, estrogen treatment, fertility, co-morbidities, and neurocognition and neuropsychology. Exploratory meetings were held in 2021 in Europe and United States culminating with a consensus meeting in Aarhus, Denmark in June 2023. Prior to this, eight groups addressed important areas in TS care: (1) diagnosis and genetics, (2) growth, (3) puberty and estrogen treatment, (4) cardiovascular health, (5) transition, (6) fertility assessment, monitoring, and counselling, (7) health surveillance for comorbidities throughout the lifespan, and (8) neurocognition and its implications for mental health and well-being. Each group produced proposals for the present guidelines, which were meticulously discussed by the entire group. Four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with systematic review of the literature. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with members from the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology, the European Reference Network on Rare Endocrine Conditions, the Society for Endocrinology, and the European Society of Cardiology, Japanese Society for Pediatric Endocrinology, Australia and New Zealand Society for Pediatric Endocrinology and Diabetes, Latin American Society for Pediatric Endocrinology, Arab Society for Pediatric Endocrinology and Diabetes, and the Asia Pacific Pediatric Endocrine Society. Advocacy groups appointed representatives for pre-meeting discussions and the consensus meeting.

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

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

Live birth after single euploid frozen embryo transfer in a 39-year-old woman with high-grade mosaic Turner syndrome

OBJECTIVE

To describe the reproductive and obstetric outcomes of an intracytoplasmic sperm injection cycle with preimplantation genetic testing for aneuploidy in an advanced reproductive-age woman with high-grade mosaic Turner syndrome.

METHODS

Case report of a 39-year-old woman diagnosed with mosaic Turner Syndrome 45,X[90]/46,XX[10] karyotype who underwent in vitro fertilization treatment with blastocyst trophectoderm biopsy for preimplantation genetic testing using next-generation sequencing.

RESULT(S)

Two of the four blastocysts biopsied were euploid. The patient achieved ongoing pregnancy after the first single euploid frozen embryo transfer, followed by the birth of a healthy child.

CONCLUSION

Autologous intracytoplasmic sperm injection cycles can be considered in a select group of advanced reproductive-age women diagnosed with high-grade mosaic Turner syndrome.

TurnerFertility trial: fertility preservation in young girls with Turner syndrome by freezing ovarian cortex tissue-a prospective intervention study

OBJECTIVE

To evaluate which girls with Turner syndrome (TS) could benefit from fertility preservation by ovarian tissue cryopreservation on the basis of karyotype, puberty status, and hormonal data.

DESIGN

Prospective intervention study; participants were included between 2018 and 2020.

SETTING

Tertiary hospital in the Netherlands.

PATIENTS

In total, 106 girls with TS aged between 2 and 18 years were included. Girls with minor X chromosome deletions, Y chromosomal content, active infections, or contraindications for surgery were excluded.

INTERVENTION

A laparoscopic unilateral ovariectomy was performed to obtain ovarian cortical tissue for cryopreservation. One tissue fragment per participant was used to determine the number of follicles per ovary by serial sectioning and staining. Chromosome analysis was performed on lymphocytes and buccal cells. A blood sample was taken before the ovariectomy for hormonal analysis.

MAIN OUTCOME MEASURES

The presence of follicles in ovarian cortex tissue from girls with TS in relation to karyotype, puberty status, and hormonal data.

RESULTS

A unilateral ovariectomy was performed on 93 girls with TS. Complications after surgery occurred in 5 girls, including luxation of psychological symptoms in 2 girls. In 13 (14%) girls, a 46,XX cell line was found in buccal cells that was absent in lymphocytes. Follicles were observed in 30 (32%) of the 93 girls and were found mainly in girls with a 46,XX cell line in lymphocytes or buccal cells (Phi coefficient = 0.55). Spontaneous onset of puberty (Phi coefficient = 0.59), antimüllerian hormone (AMH; point-biserial correlation [r] = 0.82), inhibin B (r = 0.67), and follicle-stimulating hormone (r = -0.46) levels were also correlated strongly with the presence of follicles. Furthermore, AMH levels had a significant correlation with the number of follicles per ovary (r = 0.66).

CONCLUSION

Favorable predictive markers for the presence of follicles included either a 46,XX cell line, spontaneous onset of puberty, or a combination of measurable AMH and normal follicle-stimulating hormone levels. Karyotyping of two peripheral cell lines in girls with TS is recommended to reveal hidden mosaicisms. Ovarian tissue cryopreservation should be offered with caution in a research setting to those with a sufficient ovarian reserve, considering the significant loss of follicles after ovarian tissue cryopreservation and autotransplantation. Physicians should pay attention to the mental health of the girls during the whole process.

CLINICAL TRIAL REGISTRATION NUMBER

Trial registration number: NCT03381300- Preservation of Ovarian Cortex Tissue in Girls With Turner Syndrome - Full Text View - ClinicalTrials.gov. Registered on: December 21, 2017. First patient recruited on January 1, 2018.

Reproductive Outcomes of Women with Turner Syndrome Undergoing Oocyte Vitrification: A Retrospective Multicenter Cohort Study

BACKGROUND

Turner syndrome (TS) is accompanied with premature ovarian insufficiency. Oocyte vitrification is an established method to preserve fertility. However, data on the oocyte yield in women with TS who vitrify their oocytes and the return rate to utilize the oocytes are scarce.

METHODS

Retrospective multicenter cohort study. Data was collected from medical records of women with TS who started oocyte vitrification between 2010 and 2021.

RESULTS

Thirty-three women were included. The median cumulative number of vitrified oocytes was 20 per woman. Complications occurred in 4% of the cycles. Significant correlations were found between the cumulative number of vitrified oocytes and AMH (r = 0.54 and p < 0.01), AFC (r = 0.49 and p < 0.01), percentage of 46,XX cells (r = 0.49 and p < 0.01), and FSH (r = -0.65 and p < 0.01). Spontaneous (n = 8) and IVF (n = 2) pregnancies occurred in 10 women ± three years after vitrification. So far, none of the women have returned to utilize their vitrified oocytes.

CONCLUSIONS

Oocyte vitrification is a feasible fertility preservation option for women with TS, particularly in those with 46,XX cell lines or sufficient ovarian reserve. Multiple stimulation cycles are recommended to reach an adequate number of vitrified oocytes for pregnancy. It is too early to draw conclusions about the utilization of vitrified oocytes in women with TS.

Clinical pregnancy in Turner syndrome following re-implantation of cryopreserved ovarian cortex

Turner syndrome (TS) leads to a characteristic phenotype, including premature ovarian insufficiency and infertility. Ovarian tissue cryopreservation (OTC) is becoming an established fertility preservation strategy for both pre- and post-pubertal females and may offer the chance of having a biological family to selected patients with TS. To date, women with TS have had ovarian tissue cryopreserved but there are few reports of autologous re-implantation and none of pregnancy. We herein report, to our knowledge, the first clinical pregnancy in a patient with TS, conceived naturally following re-implantation of cryopreserved ovarian tissue which had been removed soon after spontaneous puberty. This provides proof of concept for OTC as a means of fertility preservation in TS.

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.

AMH and other markers of ovarian function in patients with Turner syndrome - a single center experience of transition from pediatric to gynecological follow up

Turner syndrome (TS) is a chromosomal disorder that affects about 1 in 2500 female births and is characterized by the partial or complete absence of the second X chromosome. Depending on karyotype, TS is associated with primary ovarian insufficiency (POI). Approximately 50% of girls with a mosaic 45, X/46, XX karyotype may enter puberty spontaneously, but only 5-10% of women with TS achieve pregnancy without egg donation. In this review, we will evaluate the clinical use of markers of ovarian function in TS patients. Based on longitudinal studies of serum concentrations of reproductive hormones as well as ovarian morphology in healthy females and patients with TS, we will evaluate how they can be applied in a clinical setting. This is important when counseling patients and their families about future ovarian function essential for pubertal development and fertility. Furthermore, we will report on 20 years of experience of transition from pediatric to gynecological and adult endocrinological care in our center at Rigshospitalet, Copenhagen, Denmark.

Individuals with numerical and structural variations of sex chromosomes: interdisciplinary management with focus on fertility potential

Diagnosis and management of individuals who have differences of sex development (DSD) due to numerical or structural variations of sex chromosomes (NSVSC) remains challenging. Girls who have Turner syndrome (45X) may present with varying phenotypic features, from classical/severe to minor, and some remain undiagnosed. Boys and girls who have 45,X/46,XY chromosomal mosaicism may have Turner syndrome-like features and short stature; therefore, unexplained short stature during childhood requires karyotype analysis in both sexes, particularly if characteristic features or atypical genitalia are present. Many individuals with Klinefelter syndrome (47XXY) remain undiagnosed or are only diagnosed as adults due to fertility problems. Newborn screening by heel prick tests could potentially identify sex chromosome variations but would have ethical and financial implications, and in-depth cost-benefit analyses are needed before nationwide screening can be introduced. Most individuals who have NSVSC have lifelong co-morbidities and healthcare should be holistic, personalized and centralized, with a focus on information, psychosocial support and shared decision-making. Fertility potential should be assessed individually and discussed at an appropriate age. Oocyte or ovarian tissue cryopreservation is possible in some women who have Turner syndrome and live births have been reported following assisted reproductive technology (ART). Testicular sperm cell extraction (TESE) is possible in some men who have 45,X/46,XY mosaicism, but there is no established protocol and no reported fathering of children. Some men with Klinefelter syndrome can now father a child following TESE and ART, with multiple reports of healthy live births. Children who have NSVSC, their parents and DSD team members need to address possibilities and ethical questions relating to potential fertility preservation, with guidelines and international studies still needed.

Summary of the ISFP congress, Brussels, 10-12 November, 2022

The 7th International Congress of the ISFP was held in Brussels in November 2022. Hundreds of attendees from all over the world had the rare opportunity to hear the most distinguished leaders discuss and debate the latest advances in the field. Participants were also able to attend workshops under the guidance of skilled practitioners. Numerous topics were considered, including a recap on fertility preservation approaches in cancer and benign pathologies and a section on male factor infertility. Other aspects covered were in vitro maturation and poor responders, the impact of chemotherapy on the ovary, and future perspectives. Participants had the chance to listen to a symposium on fertility preservation techniques, and finally, a keynote lecture on fertility preservation in gynecological cancers brought this prominent and highly influential event to a close.

The Changing Face of Turner Syndrome

Turner syndrome (TS) is a condition in females missing the second sex chromosome (45,X) or parts thereof. It is considered a rare genetic condition and is associated with a wide range of clinical stigmata, such as short stature, ovarian dysgenesis, delayed puberty and infertility, congenital malformations, endocrine disorders, including a range of autoimmune conditions and type 2 diabetes, and neurocognitive deficits. Morbidity and mortality are clearly increased compared with the general population and the average age at diagnosis is quite delayed. During recent years it has become clear that a multidisciplinary approach is necessary toward the patient with TS. A number of clinical advances has been implemented, and these are reviewed. Our understanding of the genomic architecture of TS is advancing rapidly, and these latest developments are reviewed and discussed. Several candidate genes, genomic pathways and mechanisms, including an altered transcriptome and epigenome, are also presented.

Ovarian dysfunction in women with Turner syndrome

Ovarian dysfunction is one of the most common features of women with Turner syndrome. In these women, oocyte apoptosis is markedly accelerated from the early stage of fetal life. Reduction in the number of germ cells disturbs primordial follicle development and thereby leads to the formation of streak gonads. There are three possible causes of accelerated germ cell loss in 45,X ovaries. First, chromosomal pairing failure due to X chromosomal aneuploidy is believed to induce meiotic arrest. Indeed, it has been suggested that the dosage of the X chromosome is more critical for the survival of the oocytes than for other cells in the ovary. Second, impaired coupling between oocytes and granulosa cells may also contribute to germ cell apoptosis. Previous studies have shown that 45,X ovaries may tend to lose tight junctions which are essential for intercellular interactions. Lastly, ovarian dysfunction in women with Turner syndrome is partly attributable to the reduced dosage of several genes on the X chromosome. Specifically, BMP15, PGRMC1, and some other genes on the X chromosome have been implicated in ovarian function. Further studies on the mechanisms of ovarian dysfunction are necessary to improve the reproductive outcomes of women with Turner syndrome.

The Decision-Making Process regarding Ovarian Tissue Cryopreservation in Girls with Turner Syndrome by Patients, Parents, and Healthcare Providers: A Mixed-Methods Study

INTRODUCTION

Ovarian tissue cryopreservation (OTC) has proven to be effective in other patient groups, but the effectiveness in girls with Turner syndrome (TS) is still unclear. Guidelines for counselling about OTC in TS are lacking. The aim of this study was to gain insight into the experiences of patients, parents, and healthcare providers with the decision-making process regarding OTC in girls with TS.

METHODS

Within a year after counselling, a survey was sent to 132 girls with TS and their parents. Furthermore, focus groups were conducted with (1) gynaecologists with subspeciality reproductive medicine, (2) paediatric endocrinologists, (3) parents of girls aged 2-12, and (4) parents of girls aged 13-18. Transcripts were analysed using a thematic analysis approach.

RESULTS

The response rate of the survey was 45%. Of the survey respondents, 90% appreciated counselling regarding their future parenting options and considered it an addition to existing healthcare. Girls with TS and their parents indicated that the option of OTC raised hope for future genetic offspring and instantly made them feel that their only option was to seize this opportunity. Gynaecologists and paediatricians found it challenging to truly make families grasp a realistic perspective of OTC in girls with TS.

DISCUSSION AND CONCLUSION

Offering young girls with TS the possibility of fertility preservation in an experimental setting raised high hopes and led to challenges for healthcare providers in ensuring a considered decision. The appropriate moment for counselling should be tailored to the individual and discussed with patient, parents, and paediatrician.

Why Turner patients with 45, X monosomy should not be excluded from fertility preservation services

In this case report, we highlight the practical dilemma, i.e. to perform ovarian tissue cryopreservation surgery in a 45, X Turner Syndrome patient or not, by reporting on the presence of follicles in a 13-year-old female diagnosed with 45, X monosomy and an unmeasurable anti-müllerian hormone serum level. We compare our results with previous research, highlight the challenges we faced in this case and provide recommendations for daily practice. Hereby, we demonstrate that excluding certain subgroups of Turner Syndrome patients (e.g. monosomy patients, and/or girls with an anti-müllerian hormone level below 2.0 ng/l) may be premature, especially based on the current state of published research data. This practical example of a challenging dilemma in the counselling of Turner Syndrome patients for fertility preservation is of interest for clinicians involved in fertility counselling and Turner Syndrome care.

Turner Syndrome and Fertility

Turner syndrome (TS) is tightly associated with hypergonadotropic hypogonadism and ovarian dysgenesis, typically resulting in infertility in the great majority of patients. Therefore females with TS are usually treated with female sex steroids from 11-12 years of age until the normal age of natural menopause of around 53-54 years of age. Infertility is rated among females with TS as a distressing concern and a detractor from a good quality of life. Options for motherhood for females with TS has expanded during recent years. Originally, only adoption was an option, unless of course for the small minority of TS females that still has ovarian function and are capable of achieving pregnancy through normal means. Oocyte donation has become the mainstream option in many countries and seems to work well, especially if patients have been treated with optimal estrogen and gestagen for a prolonged time before the intervention. It comes with an increased risk of cardiovascular complications and TS oocyte donation pregnancies are viewed as high risk pregnancies necessitating increased vigilance. Oocyte cryopreservation of own oocytes is also becoming an option in a select group of TS and has special challenges. Ovarian tissue cryopreservation is a promising new techniques that has been applied successfully in children with cancer. Currently, several trials are running around the world evaluating this techniques in TS. The genetics and genomics behind the ovarian dysgenesis seen in TS is not understood, but new studies have elucidated global changes in DNA methylation and RNA expression in blood from persons with TS and it is likely that similar changes are present in the ovaries. We still, however, need more thorough research to fully uncover the genetic background of ovarian failure in TS. Gene expression studies and methylation analysis from ovarian TS tissues still needs to be performed.

The Hypothesis of the Prolonged Cell Cycle in Turner Syndrome

Turner syndrome (TS) is a chromosomal disorder that is caused by a missing or structurally abnormal second sex chromosome. Subjects with TS are at an increased risk of developing intrauterine growth retardation, low birth weight, short stature, congenital heart diseases, infertility, obesity, dyslipidemia, hypertension, insulin resistance, type 2 diabetes mellitus, metabolic syndrome, and cardiovascular diseases (stroke and myocardial infarction). The underlying pathogenetic mechanism of TS is unknown. The assumption that X chromosome-linked gene haploinsufficiency is associated with the TS phenotype is questioned since such genes have not been identified. Thus, other pathogenic mechanisms have been suggested to explain this phenotype. Morphogenesis encompasses a series of events that includes cell division, the production of migratory precursors and their progeny, differentiation, programmed cell death, and integration into organs and systems. The precise control of the growth and differentiation of cells is essential for normal development. The cell cycle frequency and the number of proliferating cells are essential in cell growth. 45,X cells have a failure to proliferate at a normal rate, leading to a decreased cell number in a given tissue during organogenesis. A convergence of data indicates an association between a prolonged cell cycle and the phenotypical features in Turner syndrome. This review aims to examine old and new findings concerning the relationship between a prolonged cell cycle and TS phenotype. These studies reveal a diversity of phenotypic features in TS that could be explained by reduced cell proliferation. The implications of this hypothesis for our understanding of the TS phenotype and its pathogenesis are discussed. It is not surprising that 45,X monosomy leads to cellular growth pathway dysregulation with profound deleterious effects on both embryonic and later stages of development. The prolonged cell cycle could represent the beginning of the pathogenesis of TS, leading to a series of phenotypic consequences in embryonic/fetal, neonatal, pediatric, adolescence, and adulthood life.

First live birth after fertility preservation using vitrification of oocytes in a woman with mosaic Turner syndrome

PURPOSE

To report the case of a young woman diagnosed with Turner syndrome (TS) who achieved a live birth using her own oocytes that had been vitrified for fertility preservation.

METHODS

A 25-year-old woman with mosaic (45,X/46,XX) TS was referred for fertility preservation (FP) counseling. Serum anti-Müllerian hormone (AMH) level was normal (6.4 µg/L). In view of the unpredictable rate of follicle loss in TS individuals, she requested FP and underwent two cycles of ovarian stimulation (OS) for oocyte cryopreservation (OoC) using a GnRH antagonist protocol and recombinant follicle stimulating hormone (rFSH), 200-250 IU daily for 8 resp. 12 days.

RESULTS

In total, 29 metaphase II oocytes (MII) were vitrified after OS. After conceiving spontaneously and achieving a live birth, she returned to the clinic five years after OoC with a desire for pregnancy using in vitro fertilization (IVF) of her cryopreserved oocytes and preimplantation genetic testing (PGT-A). All 29 MII oocytes were thawed; 23 oocytes survived (79.3%) and were inseminated with partner sperm using intracytoplasmic sperm injection (ICSI). Thirteen oocytes were fertilized resulting in three good quality blastocysts which were vitrified after trophectoderm biopsy for PGT-A using array-CGH. Two blastocysts were found to be euploid. One was thawed and transferred to the uterus using a HRT priming protocol. An uneventful pregnancy occurred. The patient delivered a healthy baby girl weighing 3490 g at 40 weeks of gestation.

CONCLUSIONS

We report the first live birth achieved using cryopreserved oocytes in a woman diagnosed with mosaic TS. Cryopreservation of oocytes after ovarian stimulation is a realistic option for FP in selected post menarche individuals with mosaic TS. Whether PGT-A may reduce the risk of pregnancy loss in TS has to be confirmed by further studies.

Clinical Utility of Anti-Mullerian Hormone in Pediatrics

CONTEXT

Anti-Mullerian hormone (AMH) was originally described in the context of sexual differentiation in the male fetus but has gained prominence now as a marker of ovarian reserve and fertility in females. In this mini-review, we offer an updated synopsis on AMH and its clinical utility in pediatric patients.

DESIGN AND RESULTS

A systematic search was undertaken for studies related to the physiology of AMH, normative data, and clinical role in pediatrics. In males, AMH, secreted by Sertoli cells, is found at high levels prenatally and throughout childhood and declines with progression through puberty to overlap with levels in females. Thus, serum AMH has clinical utility as a marker of testicular tissue in males with differences in sexual development and cryptorchidism and in the evaluation of persistent Mullerian duct syndrome. In females, serum AMH has been used as a predictive marker of ovarian reserve and fertility, but prepubertal and adolescent AMH assessments need to be interpreted cautiously. AMH is also a marker of tumor burden, progression, and recurrence in germ cell tumors of the ovary.

CONCLUSIONS

AMH has widespread clinical diagnostic utility in pediatrics but interpretation is often challenging and should be undertaken in the context of not only age and sex but also developmental and pubertal stage of the child. Nonstandardized assays necessitate the need for assay-specific normative data. The recognition of the role of AMH beyond gonadal development and maturation may usher in novel diagnostic and therapeutic applications that would further expand its utility in pediatric care.

Ovarian tissue cryopreservation for a 3-year-old girl with Mosaic Turner syndrome in China: First case report and literature review

BACKGROUND

Although it cannot be predicted accurately which young females will develop premature ovarian insufficiency (POI) following chemotherapy or irradiation, patients at high risk of POI should be offered ovarian tissue cryopreservation (OTC). Our ovarian tissue cryobank is the first center in China. OTC was firstly performed on a 3-year-old girl with mosaic Turner syndrome (TS) in China. We report this case and present a literature review about TS girls' fertility preservation (FP).

CASE PRESENTATION

Karyotype analysis of umbilical cord blood showed that the girl was diagnosed with TS, 45,X [19]/46,XX [81]. The girl was a 3-year-old girl when her parents would like OTC to preserve fertility. No abnormality was found in the reproductive system, abdominal and cardiac ultrasound, spinal X-ray, and bone age. She was treated with growth hormone (GH) one year ago because of her short stature. GH has been discontinued now. Because of the high risk of POI, OTC was planned. The hormone level before OTC was FSH 4.27 IU/L, LH 0.00 IU/L, E2 < 11.80 pg/ml, AMH 1.06 ng/ml. Pelvic ultrasound showed that the size of the bilateral ovaries was 1.6 cm×0.7-0.8 cm, no enlarged follicles were found, and the maximum diameter of follicles was 0.2-0.37 cm. Ovarian tissue for OTC was taken from the whole right ovary by laparoscopic surgery, and the antral follicles could be seen in ovarian tissue preparation. Sixteen ovarian cortical slices were cryopreserved by slow freezing, with an average of 1380 follicles in round cortical tissue with a diameter of 2 mm, and the follicular density was about 440/mm³. The ovarian tissue from 10 children with non-TS was cryopreserved in our center, the median age was 5 (range 2-8) years old, and the median number of follicles was 766 (range 163-2250) per 2 mm biopsy. The follicles number in this girl were within normal range.

CONCLUSION

TS patients should be evaluated early in childhood to benefit from FP. For highly selected young females with mosaic TS, if the endocrine evaluation does not indicate POI and other health problems do not rule out future pregnancy, it seems reasonable to consider OTC as an FP option.

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].

Fertility Preservation: How to Preserve Ovarian Function in Children, Adolescents and Adults

Chemotherapy, pelvic radiotherapy and ovarian surgery have known gonadotoxic effects that can lead to endocrine dysfunction, cessation of ovarian endocrine activity and early depletion of the ovarian reserve, causing a risk for future fertility problems, even in children. Important determinants of this risk are the patient’s age and ovarian reserve, type of treatment and dose. When the risk of premature ovarian insufficiency is high, fertility preservation strategies must be offered to the patient. Furthermore, fertility preservation may sometimes be needed in conditions other than cancer, such as in non-malignant diseases or in patients seeking fertility preservation for personal reasons. Oocyte and/or embryo vitrification and ovarian tissue cryopreservation are the two methods currently endorsed by the American Society for Reproductive Medicine, yielding encouraging results in terms of pregnancy and live birth rates. The choice of one technique above the other depends mostly on the age and pubertal status of the patient, and personal and medical circumstances. This review focuses on the available fertility preservation techniques, their appropriateness according to patient age and their efficacy in terms of pregnancy and live birth rates.

Adolescent Fertility Preservation: Where Do We Stand Now

Adolescence is a period of flux for many body systems. While fertility potential typically increases after menarche, there are diseases where the opposite occurs and fertility preservation options need to be considered early. In cases of cancer, options vary by pubertal status and can include ovarian tissue cryopreservation, oocyte cryopreservation, sperm cryopreservation, and testicular tissue cryopreservation. Much remains to be learned about fertility and preservation options in those with differences in sexual development (DSDs); however, depending on the form of DSD, fertility preservation may not be necessary. Similarly, traditional fertility counseling in children with galactosemia may need to be changed, as data suggest that fertility rates attributed to other causes of premature ovarian insufficiency may not be as applicable to this disease. Adolescents with Turner's syndrome are at high risk for premature ovarian failure; therefore, it is important to consider options as early as possible since ovarian reserves are depleted quickly. On the other hand, transgender and gender diverse adolescents may even be able to undergo fertility preservation after starting hormone therapy. In all cases, there are additional ethical components including technical/surgical risks in childhood, offering experimental therapies without creating false hope and evaluating children's consent and assent capabilities that must be considered.

Accelerated loss of oogonia and impaired folliculogenesis in females with Turner syndrome start during early fetal development

STUDY QUESTION

How are germ cell numbers and initiation of folliculogenesis affected in fetal Turner syndrome (TS) ovaries?

SUMMARY ANSWER

Germ cell development was severely affected already in early second trimester pregnancies, including accelerated oogonia loss and impaired initiation of primordial follicle formation in TS ovaries, while the phenotype in TS mosaic ovaries was less severe.

WHAT IS KNOWN ALREADY

Females with TS are characterized by premature ovarian insufficiency (POI). This phenotype is proposed to be a consequence of germ cell loss during development, but the timing and mechanisms behind this are not characterized in detail. Only few studies have evaluated germ cell development in fetal TS and TS mosaic ovaries, and with a sparse number of specimens included per study.

STUDY DESIGN, SIZE, DURATION

This study included a total of 102 formalin-fixed and paraffin-embedded fetal ovarian tissue specimens. Specimens included were from fetuses with 45,X (N = 42 aged gestational week (GW) 12-20, except one GW 40 sample), 45,X/46,XX (N = 7, aged GW 12-20), and from controls (N = 53, aged GW 12-42) from a biobank (ethics approval # H-2-2014-103).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The number of OCT4 positive germ cells/mm2, follicles (primordial and primary)/mm2 and cPARP positive cells/mm2 were quantified in fetal ovarian tissue from TS, TS mosaic and controls following morphological and immunohistochemical analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjusting for gestational age, the number of OCT4+ oogonia was significantly higher in control ovaries (N = 53) versus 45,X ovaries (N = 40, P < 0.001), as well as in control ovaries versus 45,X/46,XX mosaic ovaries (N = 7, P < 0.043). Accordingly, the numbers of follicles were significantly higher in control ovaries versus 45,X and 45,X/46,XX ovaries from GW 16-20 with a median range of 154 (N = 11) versus 0 (N = 24) versus 3 (N = 5) (P < 0.001 and P < 0.015, respectively). The number of follicles was also significantly higher in 45,X/46,XX mosaic ovaries from GW 16-20 compared with 45,X ovaries (P < 0.005). Additionally, the numbers of apoptotic cells determined as cPARP+ cells/mm2 were significantly higher in ovaries 45,X (n = 39) versus controls (n = 15, P = 0.001) from GW 12-20 after adjusting for GW.

LIMITATIONS, REASONS FOR CAUTION

The analysis of OCT4+ cells/mm2, cPARP+ cells/mm2 and follicles (primordial and primary)/mm2 should be considered semi-quantitative as it was not possible to use quantification by stereology. The heterogeneous distribution of follicles in the ovarian cortex warrants a cautious interpretation of the exact quantitative numbers reported. Moreover, only one 45,X specimen and no 45,X/46,XX specimens aged above GW 20 were available for this study, which unfortunately made it impossible to assess whether the ovarian folliculogenesis was delayed or absent in the TS and TS mosaic specimens.

WIDER IMPLICATIONS OF THE FINDINGS

This human study provides insights about the timing of accelerated fetal germ cell loss in TS. Knowledge about the biological mechanism of POI in girls with TS is clinically useful when counseling patients about expected ovarian function and fertility preservation strategies.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC).

TRIAL REGISTRATION NUMBER

N/A.

Added value of buccal cell FISH analysis in the diagnosis and management of Turner syndrome

STUDY QUESTION

Is there an added diagnosis value of buccal cell FISH analysis compared with blood lymphocyte chromosomal investigations in patients with Turner syndrome (TS)?

SUMMARY ANSWER

Buccal cell FISH analysis, a non-invasive technique, modified the chromosomal results obtained with the blood karyotype in 17 patients (12%) of our cohort.

WHAT IS KNOWN ALREADY

Few studies have evaluated buccal cell FISH analysis and compared them with blood karyotype in patients with TS.

STUDY DESIGN, SIZE, DURATION

A prospective, monocentric cohort study was conducted in a rare diseases centre (CMERC) between July 2017 and August 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In total, 142 adult patients with TS, and at least 5% 45,X cells in a previous blood karyotype, were recruited. All the patients' files were included in the CEMARA database. This national database has been declared to the French data protection agency (CNIL approval number 1187326). In compliance with French law, consent regarding non-opposition to collect and use the data was obtained from each patient. A FISH analysis on a buccal smear was performed.

MAIN RESULTS AND THE ROLE OF CHANCE

The percentage of 45,X cells was identical between the two tissues in only 32.4% of cases. The discrepancy was higher than 41% for 12% of the cohort. The percentage of 45,X cells was higher in blood in 53 (37.3%) patients, and higher in buccal cells in 43 (30.3%) of cases. In 17 (12%) cases, the blood karyotype had to be reconsidered in regard to the buccal cell analysis.

LIMITATIONS, REASONS FOR CAUTION

It would have been interesting to evaluate karyotypes in cells from other tissues such as cells from skin biopsy or from the urinary tract and even from blood vessels or gonads in case of surgery and to compare them with each patient's phenotype. However, most of the time, these tissues are not available.

WIDER IMPLICATIONS OF THE FINDINGS

Although blood lymphocyte karyotype remains the gold standard for the diagnosis of TS, buccal cell FISH analysis is an efficient tool to evaluate the global chromosomal constitution in these patients, thus allowing them to have better care and follow-up. For instance, identifying a Y chromosome can prevent the occurrence of a gonadoblastoma, as gonadectomy should be discussed. On the other hand, finding normal XX cells in a patient with a previous diagnosis of homogenous 45,X TS, may be psychologically helpful and relevant for gynaecological care.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was sought for the study. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Ovarian tissue freezing and activation after thawing: an update

Background

With the growth of women’s age, ovarian failure can be caused by various factors. For the women who need chemotherapy because of cancer factors, the preservation of fertility is more urgent. The treatment of cancer is also a process in which all tissues and organs of the body are severely damaged, especially in the reproductive system.

Main body

As a new fertility preservation technology, autologous ovarian tissue cryopreservation and transplantation is developing rapidly and showing great potentiality in preserving ovarian endocrine function of young cervical cancer patients. Vitrification and slow freezing are two common techniques applied for ovarian tissue cryopreservation. Thus, cryopreserved/thawed ovarian tissue and transplantation act as an important method to preserve ovarian function during radiotherapy and chemotherapy, and ovarian cryopreservation by vitrification is a very effective and extensively used method to cryopreserve ovaries. The morphology of oocytes and granulosa cells and the structure of organelles were observed under the microscope of histology; the hormone content in the stratified culture medium of granulosa cells with the diameter of follicle was used to evaluate the development potential of ovarian tissue, and finally the ovarian tissue stimulation was determined by the technique of ovarian tissue transplantation.

Conclusions

Although there are some limitations, the team members still carry out this review to provide some references and suggestions for clinical decision-making and further clinical research.

Karyotype is associated with timing of ovarian failure in women with Turner syndrome

OBJECTIVE

To characterize the age of ovarian failure in Turner Syndrome (TS) patients by karyotype.

METHODS

Retrospective cohort study of individuals with TS at an academic university hospital. Subjects were seen in TS Clinic at UNC Hospital between 2014 and 2018. Individuals were analyzed by karyotype category (45X, 45X/46XX mosaicism, miscellaneous) and percentage of 45X cells. Age at follicle-stimulating hormone> 30 was defined as the age at loss of ovarian function.

RESULTS

A total of 79 patients were identified after excluding individuals with unknown ovarian function and those with Y chromosome material. Thirty-eight percent were 45X monosomic, 62% were 45X/46XX mosaic or miscellaneous karyotypes. Fifty-five of 79 (70%) patients had evidence of ovarian failure, median age of failure 11 years (IQR: 4,12). Ovarian failure was more prevalent among individuals with 45X karyotype (100%). The median age of ovarian failure for 45X patients (n=30) was 10 years old, which is significantly younger than other karyotypes (n=49), with a median of 15 years, p<0.01. Linear regression analysis found that 1 percentage point increase in 45X cells in the peripheral karyotype is associated with a 0.09 year decrease in age of ovarian failure (p value=0.01). Only 9% of individuals were referred for fertility counseling.

CONCLUSIONS

There is a lower prevalence of ovarian failure among individuals with mosaic TS karyotypes, and referral rate for fertility counseling of patients with TS is low. These findings are in line with published literature. The finding that percentage of 45X cells in peripheral karyotype is associated with earlier age of ovarian failure is novel and warrants further investigation in a larger prospective cohort.

Chromosomal Analysis of Cumulus Cells as a Future Predictor for Oocyte Aneuploidy: A Case Report

Background:

Within the ovary, the optimal growth of the follicle, oocyte maturation and ovulation are highly conditioned by the two-way cross talk and interactions between the oocyte and the immediate somatic cells, known as cumulus cells (CCs). This biological communication between cell lines triggered the interest in the study of CCs as a biomarker of oocyte competence.

Case Presentation:

The findings of a 45,X mosaic pattern on CCs from a female patient with unremarkable medical history are reported in this study. The patient came to the Centre for Reproductive and Genetic Health, London on 14th August 2019 for her first visit and the follow up procedures were done for her to determine underlying genetic status. For this purpose, four sources of DNA including CCs, blood lymphocytes, buccal cells and immature oocytes were analyzed in the present report.

Conclusion:

In the present case study, the hypothesis of the female patient being mosaic 45,X was confirmed although the degree of mosaicism and whether this was affecting the germinal line could not be determined. In the event of the discovery of a cell line with an apparently abnormal genetic makeup, genetic counselling is important in order to understand the implications from somatic to germinal cells for patients exploring fertility journeys.

Reproductive outcomes after preimplantation genetic testing in mosaic Turner syndrome: a retrospective cohort study of 100 cycles

PURPOSE

The purpose of this study is to explore the reproductive outcomes of women with Turner syndrome (TS) in preimplantation genetic testing (PGT) cycles.

METHODS

A retrospective study of 100 controlled ovarian stimulating cycles, 68 TS (sixty-four mosaic Turner syndrome (MTS) and four pure Turner syndrome (PTS)) women underwent PGT was conducted from 2013 to 2018.

RESULTS

Embryo X chromosome abnormal rates of TS women were significantly higher than women with normal karyotype (7.04 vs 1.61%, P<0.01). Cumulative live birth rates (CLBR) after PGT-NGS treatment were lower in TS than control (31.15 vs 45.59%, P<0.05). Clinical pregnancy rates per transfer (CPR), miscarriage rates (MR) and live birth rates per transfer (LBR) remained comparable between TS and control group. Reproductive outcomes (X chromosome abnormal rates, CPR, MR, LBR and CLBR) among low (<10%), medium (10-50%) and high (>50%) level 45,X mosaicism groups were not statistically different.

CONCLUSIONS

To avoid high risk of embryo X chromosome abnormalities, prenatal or preimplantation genetic testing should be recommended to mosaic or pure TS patients.

Why are some patients with 45,X Turner syndrome fertile? A young girl with classical 45,X Turner syndrome and a cryptic mosaicism in the ovary

OBJECTIVE

To report a case of a young girl initially diagnosed with exclusively 45,X Turner syndrome (TS), but with a cryptic mosaicism in the ovary.

DESIGN

Case report.

SETTING

Radboud University Medical Center in the Netherlands.

PATIENT(S)

A 14-year-old girl with TS showing an exclusively 45,X cell line in lymphocytes, buccal cells, and urine cells in the presence of ovarian follicles.

INTERVENTION(S)

Laparoscopic unilateral oophorectomy was performed to obtain ovarian cortex tissue for fertility preservation purposes. One cortex fragment was used to determine the number of follicles by serial sectioning and staining, to perform fluorescence in situ hybridization (FISH) analysis and an in vitro growth (IVG) assay.

MAIN OUTCOME MEASURE(S)

FISH analysis of ovarian cells and the capacity of unilaminar follicles to develop to secondary follicles.

RESULT(S)

FISH analysis revealed that most oocytes had a normal tetraploid X chromosomal content, the stromal cell compartment had both 45,X and 47,XXX cell lines, and all follicular granulosa cells had a 45,X karyotype. IVG assay showed that unilaminar follicles were capable of maturing to secondary follicles, but that the granulosa layers and membrana granulosa were distorted.

CONCLUSION(S)

We report a case where follicles were found in a girl with monosomic TS, in the presence of a cryptic mosaicism. Karyotyping of extraovarian cells was not predictive of the karyotype of ovarian cells in the same patient. Despite the presence of normal oocytes, our observation that all analyzed follicles contained exclusively 45,X granulosa cells embedded in mosaic 45,X/47,XXX stromal tissue may have functional consequences for follicular development.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03381300.

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.

The indication for fertility preservation in women with Turner syndrome should not only be based on the ovarian reserve but also on the genotype and expected future health status

Fertility preservation in women with Turner syndrome is highly controversial. Some strongly recommend freezing of ovarian tissue at a young age, others do not. The controversy is partly due to different perspectives and professions. Biologists prefer to freeze young ovaries with high follicle density, reproductive physicians want to avoid risky operations and iatrogenic infertility by removing one ovary, and cardiologists and obstetricians warn against the risks of later pregnancies. Accordingly, fertility preservation in young women with Turner syndrome is more than just the freezing of ovarian tissue or oocytes. Fertility preservation requires a balanced decision considering the conservation of fertility, the protection of reproductive health, and future health consequences. Therefore, fertility preservation strategies should be based not only on the individual ovarian reserve but also on the genotype and the expected cardiac health status to decide what is the best option: to freeze tissue or alternatively to wait and see.

Premature ovarian insufficiency in the XO female mouse on the C57BL/6J genetic background

In humans, all but 1% of monosomy 45.X embryos die in utero and those who reach term suffer from congenital abnormalities and infertility termed Turner's syndrome (TS). By contrast, XO female mice on various genetic backgrounds show much milder physical defects and normal fertility, diminishing their value as an animal model for studying the infertility of TS patients. In this article, we report that XO mice on the C57BL/6J (B6) genetic background showed early oocyte loss, infertility or subfertility and high embryonic lethality, suggesting that the effect of monosomy X in the female germline may be shared between mice and humans. First, we generated XO mice on either a mixed N2(C3H.B6) or B6 genetic background and compared the number of oocytes in neonatal ovaries; N2.XO females retained 45% of the number of oocytes in N2.XX females, whereas B6.XO females retained only 15% of that in B6.XX females. Second, while N2.XO females were as fertile as N2.XX females, both the frequency of delivery and the total number of pups delivered by B6.XO females were significantly lower than those by B6.XX females. Third, after mating with B6 males, both N2.XO and B6.XO females rarely produced XO pups carrying paternal X chromosomes, although a larger percentage of embryos was found to be XO before implantation. Furthermore, B6.XO females delivered 20% XO pups among female progeny after mating with C3H males. We conclude that the impact of monosomy X on female mouse fertility depends on the genetic background.

TurnerFertility trial: PROTOCOL for an observational cohort study to describe the efficacy of ovarian tissue cryopreservation for fertility preservation in females with Turner syndrome

OBJECTIVE

To investigate the occurrence of live birth in women with Turner syndrome (TS) after ovarian tissue cryopreservation in childhood followed by auto transplantation in adulthood and to find reliable prognostic markers for estimating the ovarian reserve in girls with TS in the future.

SETTING

An observational cohort study with long-term follow-up in a tertiary fertility clinic in the Netherlands. Patients recruitment between January 2018 and December 2021.

PARTICIPANTS

100 females aged 2 through 18 years with classical Turner (ie, 45,X0) or Turner variants (ie, 45,X mosaicism or structural anomalies). Girls with Y chromosomal content, minor X deletions with marginal impact on fertility, active HIV, hepatitis B or hepatitis C infection, and/or an absolute contra indication for surgery, anaesthesia or future pregnancy will be excluded.

INTERVENTIONS

Ovarian cortical tissue will be harvested by performing a unilateral oophorectomy via laparoscopic approach. Ovarian cortex fragments will be prepared and cryopreserved. One fragment per patient will be used to determine follicular density by conventional histology, and to perform fluorescence in situ hybridisation analysis of ovarian cells. Routine chromosome analysis will be performed on both lymphocytes and buccal cells. A blood sample will be taken for hormonal analysis and all subjects will undergo a transabdominal ultrasound to determine the uterine and ovarian size. Patient characteristics, pregnancy rates and pregnancy outcomes will be collected from the patient's medical record.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Central Committee on Research Involving Human Subjects in November 2017 (CCMO NL57738.000.16).

TRIAL REGISTRATION NUMBER

NCT03381300.