Challenges of fertility preservation in non-oncological diseases

Exploring stem cell technology: Pioneering new pathways for female fertility preservation and restoration

The fertility of women is crucial for the well-being of individuals and families. However, various factors such as chemotherapy, lifestyle changes, among others, may lead to a decline in female fertility, thus emphasizing the significance of preserving and restoring fertility. Stem cells, with their unique capacity for self-renewal and pluripotent differentiation, have made significant strides in areas such as ovarian tissue cryopreservation, in vitro culture of frozen-thawed ovarian tissue, and construction of ovarian-like organs. This review aims to summarize the latest findings in these fields, highlighting the pivotal role, mechanisms, and future prospects of stem cell technology in preserving and restoring female fertility. Additionally, the importance of interdisciplinary collaboration is underscored, as personalized stem cell therapy regimens tailored through interdisciplinary cooperation between reproductive medicine and stem cell fields hold promise in providing reliable solutions for the preservation and restoration of female fertility.

Bioengineered 3D ovarian model for long-term multiple development of preantral follicle: bridging the gap for poly(ε-caprolactone) (PCL)-based scaffold reproductive applications

BACKGROUND

Assisted Reproductive Technologies (ARTs) have been validated in human and animal to solve reproductive problems such as infertility, aging, genetic selection/amplification and diseases. The persistent gap in ART biomedical applications lies in recapitulating the early stage of ovarian folliculogenesis, thus providing protocols to drive the large reserve of immature follicles towards the gonadotropin-dependent phase. Tissue engineering is becoming a concrete solution to potentially recapitulate ovarian structure, mostly relying on the use of autologous early follicles on natural or synthetic scaffolds. Based on these premises, the present study has been designed to validate the use of the ovarian bioinspired patterned electrospun fibrous scaffolds fabricated with poly(ε-caprolactone) (PCL) for multiple preantral (PA) follicle development.

METHODS

PA follicles isolated from lamb ovaries were cultured on PCL scaffold adopting a validated single-follicle protocol (Ctrl) or simulating a multiple-follicle condition by reproducing an artificial ovary engrafted with 5 or 10 PA (AO5PA and AO10PA). The incubations were protracted for 14 and 18 days before assessing scaffold-based microenvironment suitability to assist in vitro folliculogenesis (ivF) and oogenesis at morphological and functional level.

RESULTS

The ivF outcomes demonstrated that PCL-scaffolds generate an appropriate biomimetic ovarian microenvironment supporting the transition of multiple PA follicles towards early antral (EA) stage by supporting follicle growth and steroidogenic activation. PCL-multiple bioengineering ivF (AO10PA) performed in long term generated, in addition, the greatest percentage of highly specialized gametes by enhancing meiotic competence, large chromatin remodeling and parthenogenetic developmental competence.

CONCLUSIONS

The study showcased the proof of concept for a next-generation ART use of PCL-patterned scaffold aimed to generate transplantable artificial ovary engrafted with autologous early-stage follicles or to advance ivF technologies holding a 3D bioinspired matrix promoting a physiological long-term multiple PA follicle protocol.

Oocyte vitrification for fertility preservation is an evolving practice requiring a new mindset: societal, technical, clinical, and basic science-driven evolutions

Infertility is a condition with profound social implications. Indeed, it is not surprising that evolutions in both medicine and society affect the way in vitro fertilization is practiced. The keywords in modern medicine are the four principles, which implicitly involve a constant update of our knowledge and our technologies to fulfill the "prediction" and "personalization" tasks, and a continuous reshaping of our mindset in view of all relevant societal changes to fulfill the "prevention" and "participation" tasks. A worldwide aging population whose life priorities are changing requires that we invest in fertility education, spreading actionable information to allow women and men to make meaningful reproductive choices. Fertility preservation for both medical and nonmedical reasons is still very much overlooked in many countries worldwide, demanding a comprehensive update of our approach, starting from academia and in vitro fertilization laboratories, passing through medical offices, and reaching out to social media. Reproduction medicine should evolve from being a clinical practice to treat a condition to being a holistic approach to guarantee patients' reproductive health and well-being. Oocyte vitrification for fertility preservation is the perfect use case for this transition. This tool is acquiring a new identity to comply with novel indications and social needs, persisting technical challenges, brand-new clinical technologies, and novel revolutions coming from academia. This "views and reviews" piece aims at outlining the advancement of oocyte vitrification from all these tightly connected perspectives.

Preservation of fertility in female patients with hematologic diseases

Recent developments of assisted reproduction techniques turned possible to avoid the infertility consequences of oncologic treatments, but fertility preservation (FP) has been somewhat neglected in women with hematologic diseases undergoing gonadotoxic treatments. For these specific cases, the current options for FP include the cryopreservation of embryos, mature oocytes and ovarian tissue, and oocyte in-vitro maturation. We intend to make patients and clinicians aware of this important and relevant issue, and provide hematologists, assisted reproduction physicians and patients, with updated tools to guide decisions for FP. The physicians of the units responsible for female FP should always be available to decide on the best-individualized FP option in strict collaboration with hematologists. With a wide range of options for FP tailored to each case, a greater level of training and information is needed among clinicians, so that patients proposed to gonadotoxic treatments can be previously advised for FP techniques in hematological conditions. ABBREVIATED ABSTRACT: Recent developments of assisted reproduction techniques turned possible to preserve the fertility of women with hematologic diseases undergoing gonadotoxic treatments. Current options for fertility preservation in women with hematologic diseases are presented. It is imperative to offer fertility preservation to all women before starting any gonadotoxic treatment and in some cases after treatment. Fertility preservation methods enable to later achieve the desired pregnancy.

Fertility Preservation as an Option for Women with Genetic Disorders: Insights from a SWOT Analysis on Elective Oocyte Freezing and Preimplantation Genetic Testing

This paper uses a SWOT (strengths, weaknesses, opportunities, and threats) analysis to overview the option of fertility preservation in women with genetic diseases, who would later use preimplantation genetic testing for monogenic disorders, in order to not transmit their condition. Strengths associated with elective oocyte freezing are ethical considerations, overall maternal and fetal safety, and effectiveness, if performed at <35 years of age. Weaknesses are related to costs and rare but present (<1-3%) risks of maternal complications. Counselling on fertility management aimed at preventing infertility offers a valuable opportunity, the same as it has been in oncological patients' care. The potentially high percentage of women with genetic conditions who would return to use their frozen oocytes also represents an opportunity together with the minimization of the need for egg donation, which has higher obstetrical risks compared to the use of autologous oocytes. Finally, a threat is represented by the potential psychological distress to young women who could never attempt to become pregnant through preimplantation genetic testing, or do it before any decline in their fertility. Potential unknown future long-term health risks for children conceived after egg vitrification/thawing are also a threat, but current knowledge is reassuring. Altogether, early counselling on the option of fertility preservation should thus be incorporated into standard care of all patients with any genetic condition.

Effects of meiotic stage-specific oocyte vitrification on mouse oocyte quality and developmental competence

Introduction

Acquisition of germinal vesicle (GV) stage oocytes for fertility preservation (FP) offers several benefits over in vivo matured oocyte cryopreservation following ovarian stimulation, particularly for cancer patients necessitating immediate treatment. Two FP approaches for GV oocytes are available: vitrification before in vitro maturation (IVM) at the GV stage (GV-VI) or post-IVM at the metaphase II (MII) stage (MII-VI). The optimal method remains to be determined.

Methods

In this study, mouse oocytes were collected without hormonal stimulation and vitrified either at the GV stage or the MII stage following IVM; non-vitrified in vitro matured MII oocytes served as the control (CON). The oocyte quality and developmental competence were assessed to obtain a better method for immediate FP.

Results

No significant differences in IVM and survival rates were observed among the three groups. Nevertheless, GV-VI oocytes exhibited inferior quality, including abnormal spindle arrangement, mitochondrial dysfunction, and early apoptosis, compared to MII-VI and CON oocytes. Oocyte vitrification at the GV stage impacted maternal mRNA degradation during IVM. In addition, the GV-VI group demonstrated significantly lower embryonic developmental competence relative to the MII-VI group. RNA sequencing of 2-cell stage embryos revealed abnormal minor zygotic genome activation in the GV-VI group.

Conclusion

Vitrification at the GV stage compromised oocyte quality and reduced developmental competence. Consequently, compared to the GV stage, oocyte vitrification at the MII stage after IVM is more suitable for patients who require immediate FP.

A comprehensive review and update on human fertility cryopreservation methods and tools

The broad conceptualization of fertility preservation and restoration has become already a major concern in the modern western world since a large number of individuals often face it in the everyday life. Driven by different health conditions and/or social reasons, a variety of patients currently rely on routinely and non-routinely applied assisted reproductive technologies, and mostly on the possibility to cryopreserve gametes and/or gonadal tissues for expanding their reproductive lifespan. This review embraces the data present in human-focused literature regarding the up-to-date methodologies and tools contemporarily applied in IVF laboratories' clinical setting of the oocyte, sperm, and embryo cryopreservation and explores the latest news and issues related to the optimization of methods used in ovarian and testicular tissue cryopreservation.

Fertility preservation in women with benign gynaecological conditions

Although a wealth of data has been published regarding fertility preservation (FP) in women with malignant diseases who receive gonadotoxic treatment, the role of FP in non-malignant conditions has been studied to a much lesser extent. These include benign haematological, autoimmune, and genetic disorders, as well as a multitude of benign gynaecological conditions (BGCs) that may compromise ovarian reserve and/or reproductive potential due to pathogenic mechanisms or as a result of medical or surgical treatments. Alongside accumulating data that document the reproductive potential of cryopreserved oocytes and ovarian tissue, there is potential interest in FP for women with BGCs at risk of infertility; however, there are currently insufficient data about FP in women with BGCs to develop guidelines for clinical practice. The purpose of this article is to appraise the available evidence regarding FP for BGC and discuss potential strategies for FP based on estimated ovarian impairment and on short-term and long-term reproductive goals of patients. Cost-effectiveness considerations and patients' perspectives will also be discussed.

Fertility Preservation for Prepubertal Patients at Risk of Infertility: Present Status and Future Perspectives

The increasing cure rate of cancer has led to a vast population of survivors having to face the late adverse effects of oncological treatments, with fertility impairment being one of the most sensitive issues for patients. Different options to preserve the fertility of adult patients are routinely used in clinical practice. However, fertility preservation strategies for prepubertal patients at risk of infertility are limited to the cryopreservation of immature gonadal tissue. In recent decades, many research efforts have been focused on the future use of cryopreserved gonadal tissue. This review discusses the common status of fertility preservation measures for pediatric patients undergoing gonadotoxic treatment, focusing especially on the challenges that remain to be solved in order to implement this fundamental service.

Indications for fertility preservation not included in the 2017 Japan Society of Clinical Oncology Guideline for Fertility Preservation in Pediatric, Adolescent, and Young Adult Patients treated with gonadal toxicity, including benign diseases

In recent years, local governments in Japan have established a public financial support system for fertility preservation in pediatric, adolescent, and young adult cancer patients. Fertility preservation has become popular for patients with cancers included in the gonadal toxicity risk classification of the 2017 edition of the Guideline for Fertility Preservation in Children, Adolescents and Young Adult Cancer Patients from the Japan Society of Clinical Oncology. However, patients with cancer and non-cancer diseases that are not included in the Guideline's gonadal toxicity risk classification also often receive treatment that may affect fertility, but they are often denied the opportunity of fertility preservation because no public financial support is available for diseases not listed in the Guideline. The national research project proposes including these diseases in the indications and treatment for fertility preservation. Therefore, we cooperated with the Japan Society for Fertility Preservation and the Ministry of Health, Labour and Welfare research group to solicit opinions from experts in each therapeutic area and reviewed the literature and overseas guidelines. This paper summarizes the findings of the project. We believe that it will be an important source of information for clinicians treating patients who need fertility preservation but note that the appropriateness of fertility preservation for the disorders listed in this report needs to be continuously reviewed as medical care advances.

Pregnancy in patients with systemic lupus erythematosus after cyclophosphamide therapy

Systemic lupus erythematosus (SLE) often affects females of reproductive age and Cyclophosphamide, an alkylating agent leading to premature ovarian insufficiency (POF) and labelled category D for pregnancy is used as induction therapy for severe manifestations of lupus. There have been multiple case series reflecting variable outcomes of pregnancies after cyclophosphamide use for cancers and autoimmune diseases. With increasing maternal age, we have an increasing population of lupus patients who may wish to conceive after having received cyclophosphamide therapy. The objective of our study was to improve our understanding of the impact of cyclophosphamide exposure on fertility and pregnancy outcomes in patients with SLE.We retrospectively reviewed the charts of all patients who had received intravenous cyclophosphamide at our academic institute in the time period from 2000-2018 and identified 440 patients which included 157 female patients of reproductive age. There were 37 documented pregnancies after the cyclophosphamide infusion, of which 23 patients had successful outcomes; 4 elective abortion and 10 miscarriages. There were 17 patients who developed POF, of which 7 also had end stage renal disease. The average cumulative dose of cyclophosphamide in the patients who had successful pregnancy was 4080.37 mg compared to 2806.25 mg in those who had a miscarriage (p 0.164) and 5526.47 mg in those who developed POF (p 0.046). Using multiple regressions to evaluate risk factors impacting pregnancy outcomes, when taken as a set, the predictors including race, serological profile, exposure to steroids and Mycophenolate mofetil, age at cyclophosphamide infusion, age at pregnancy, and cumulative cyclophosphamide dose accounted for 46.29% of the variance in outcome of pregnancy (p 0.23) and 39.58% of the variance in development of premature ovarian failure (p 0.008). We noted statistical significance in the impact of maternal age at time of pregnancy (p 0.04) and duration of time between the last infusions to subsequent pregnancy (p 0.02) to pregnancy outcome.Our findings suggest that a longer time interval between the last cyclophosphamide infusion and subsequent pregnancy was favorable for a successful outcome and higher cumulative cyclophosphamide dose is more likely to be associated with premature ovarian failure.

Hot Topics on Fertility Preservation for Women and Girls-Current Research, Knowledge Gaps, and Future Possibilities

Fertility preservation is a novel clinical discipline aiming to protect the fertility potential of young adults and children at risk of infertility. The field is evolving quickly, enriched by advances in assisted reproductive technologies and cryopreservation methods, in addition to surgical developments. The best-characterized target group for fertility preservation is the patient population diagnosed with cancer at a young age since the bulk of the data indicates that the gonadotoxicity inherent to most cancer treatments induces iatrogenic infertility. Since improvements in cancer therapy have resulted in increasing numbers of long-term survivors, survivorship issues and the negative impact of infertility on the quality of life have come to the front line. These facts are reflected in an increasing number of scientific publications referring to clinical medicine and research in the field of fertility preservation. Cryopreservation of gametes, embryos, and gonadal tissue has achieved quality standards for clinical use, with the retrieval of gonadal tissue for cryopreservation being currently the only method feasible in prepubertal children. Additionally, the indications for fertility preservation beyond cancer are also increasing since a number of benign diseases and chronic conditions either require gonadotoxic treatments or are associated with premature follicle depletion. There are many remaining challenges, and current research encompasses clinical health care and caring sciences, ethics, societal, epidemiological, experimental studies, etc.

Winter is coming: the future of cryopreservation

The preservative effects of low temperature on biological materials have been long recognised, and cryopreservation is now widely used in biomedicine, including in organ transplantation, regenerative medicine and drug discovery. The lack of organs for transplantation constitutes a major medical challenge, stemming largely from the inability to preserve donated organs until a suitable recipient is found. Here, we review the latest cryopreservation methods and applications. We describe the main challenges-scaling up to large volumes and complex tissues, preventing ice formation and mitigating cryoprotectant toxicity-discuss advantages and disadvantages of current methods and outline prospects for the future of the field.

Does open ovarian biopsy in prepubertal age affect ovarian reserve in a rat model?

BACKGROUND

Partial resection of the ovary carries a possible risk of fertility reduction. We studied the influence of open ovarian biopsy on ovarian reserve, including anti-Müllerian hormone and follicle-stimulating hormone serum level evaluation, in a prepubertal rat model.

METHODS

Interventions - the initial surgery was unilateral ovarian biopsy (38 rats, group B1, B2) or unilateral ovarian biopsy and ovarian resection of the contralateral gonad (38 rats, group BR1, BR2). The second operation was bilateral ovarian resection and total resection of the remaining ovary. All rats had hormone serum levels evaluated. The control group had only a blood test taken and bilateral ovarian resection done at the second intervention (30 rats, group C1, C2). The collected tissue was examined estimating follicle count and anti-Müllerian hormone immunoexpression.

RESULTS

Anti-Müllerian hormone levels were significantly lower at the second intervention in the group BR2 but significantly higher in the group C2. Follicle-stimulating hormone levels were significantly higher in all but one group (BR2).

CONCLUSIONS

Biopsy itself might not reduce ovarian reserve if done properly but we should know its possible negative effects in the case of a single remaining ovary.

Ovarian stimulation outcomes among transgender men compared with fertile cisgender women

PURPOSE

To compare assisted reproductive technology (ART) outcomes among transgender men with those of fertile cisgender women.

METHODS

This retrospective cohort study included 12 transgender men, six with no testosterone exposure and six after testosterone treatment, and 12 cisgender women (oocyte donors) who underwent ART in our institution between June 2017 and December 2019. Statistical analyses compared ART data and outcomes between three groups: cisgender women, transgender men without testosterone exposure, and transgender men after testosterone exposure. Comparisons were also made between transgender men with and without testosterone exposure.

RESULTS

The transgender men with no testosterone exposure (23.3 ± 4 years) were significantly younger than the transgender men who had undergone testosterone treatment (30.3 ± 3.8 years; P = 0.012) and the cisgender women (29.1 ± 3.1 years; P = 0.004). The amount of FSH used for ovulation induction (1999 ± 683 mIU/mL) was significantly lower among transgender men without prior testosterone exposure compared with that among cisgender women (3150 ± 487 mIU/mL; P = 0.007). There were no differences in the peak estradiol levels, the number of oocytes retrieved, the number of MII oocytes, and the oocyte maturity rates between the three groups. Five out of six testosterone-treated transgender men underwent embryo cryopreservation, and they all achieved good-quality embryos.

CONCLUSIONS

Transgender men have an excellent response to ovulation stimulation even after long-term exposure to testosterone. Oocyte/embryo cryopreservation is, therefore, a feasible and effective way for them to preserve their fertility for future biological parenting.

Non-oncologic Indications for Male Fertility Preservation

PURPOSE OF REVIEW

To explore non-oncologic indications for male fertility preservation.

RECENT FINDINGS

Common scenarios in which male fertility could be irreversibly compromised include autoimmune conditions requiring treatment with cyclophosphamide, gender dysphoria prior to starting hormone therapy, military deployment, and critical illness. Fertility preservation should be considered with particular attention to the timing and logistics specific to each scenario. Recognition and familiarity with such situations will help physicians provide better counseling to patients and their families, improve the quality of decision-making, and ultimately reduce missed opportunities and regret.