Oocyte cryopreservation - current scenario and future perspectives: A narrative review

Navigating Uncharted Waters: A Mixed Studies Systematic Review of Elective Female Fertility Preservation for Women

AIM

This study aimed to review studies exploring the experiences and perceptions of healthcare students and providers regarding their personal choices for elective female fertility preservation and their recommendations of the same to patients.

DESIGN/METHODS

Employing Pluye and Hong's convergent qualitative synthesis approach, a mixed-studies review was conducted. The appraisal of studies was performed using the Mixed Methods Appraisal Tool and data analysis utilised Thomas and Harden's thematic synthesis approach.

DATA SOURCES

Six electronic databases (PubMed, Embase, CINAHL, PsycINFO, Scopus and Web of Science) were searched from their inception till November 2023.

RESULTS

About 24 studies were reviewed, uncovering four major themes: varied personal perspectives, knowledge gaps and role ambiguities, perceived temporal and financial constraints and apprehensions related to fear and stigma.

CONCLUSION/IMPLICATION

This review underscored the challenges faced by healthcare professionals and students in their personal pursuit of elective fertility preservation. Addressing these challenges demands the implementation of fertility navigators, culturally and religiously sensitive public health campaigns and staff training. Moreover, standardised guidelines, transparent cost and process reporting, evidence-based education, counselling on risks and success rates and governmental support in the form of subsidies can mitigate barriers, enhance cost-effectiveness and promote equitable access to care. Collaboration among stakeholders is imperative to ensure equitable access and maintain quality care in elective female fertility preservation.

REPORTING METHOD

This mixed studies review followed the reporting guidelines in the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement.

PATIENT OR PUBLIC CONTRIBUTION

No Patient or Public Contribution.

TRIAL REGISTRATION

This review has been registered on the Prospective Register of Systematic Reviews (PROSPERO) database (CRD42023395406).

[Profiles and motivations of women seeking oocyte preservation in France: A two-years' survey]

OBJECTIVES

The new bioethics law of August 2, 2021 allows French women to self-preserve.

METHODS

National observational survey over 2 years based on an online questionnaire conducted under the aegis of GEDO (Groupe d'études pour le don d'ovocytes).

RESULTS

The average age of the 282 women who answered the questionnaire, 34.5 years, is consistent with the benefit/risk balance described in the literature. The most educated women, also very vulnerable, remain the most affected. They are single and childless, but most of them see themselves as a couple and want to become mothers in the future. Their main motivation is to have the choice to postpone a pregnancy without fear of infertility until they have found a suitable partner. Careerist or selfish motivations are anecdotal. The projected fate of unused vitrified oocytes is above all donation to others.

CONCLUSION

This study shows that oocyte self-preservation is undeniably experienced as a societal victory and is perceived as a step towards gender equality. While oocyte self-preservation is not an absolute guarantee of having a future child, it is part of a primary preventive strategy for age-related fertility decline. Public authorities and health professionals will have to widely disseminate accurate and complete information to allow everyone to have access to an informed reproductive choice.

[Experiences of Unmarried Women Undergoing Planned Oocyte Cryopreservation]

PURPOSE

The present study investigated the experiences of unmarried women undergoing planned oocyte cryopreservation (OC).

METHODS

Data were collected from August 2022 to February 2023 through individual in-depth interviews with thirteen unmarried women undergoing planned OC. Data were analyzed using Colazzi's phenomenological method.

RESULTS

The findings revealed four distinct clusters. The first cluster, "Safeguards against Future Uncertainty," examined experiences associated with uncertainties in several aspects of reproductive health threats and decision-making regarding planned OC. The second cluster, "Indescribable Pain and Chaos," explored the psychological and physical pain, complications, concerns about repeat procedures, and uncertainties about the use of frozen oocytes experienced during the planned OC process and afterward. The third cluster, "Motivation to Rebuild Resilience," explored participants' resilience in overcoming difficulties and shocks during the planned OC process and regaining their inner strength through the support of family and friends. The fourth cluster, "Finally Freeing the Mind," focused on the sense of liberation from the pressure of marriage and childbirth, which enabled participants to engage in their present self and concentrate on self-stability and growth in preparation for the future.

CONCLUSION

The present study enhances our understanding of the emotional difficulties and distress experienced by women considering OC, thereby assisting in improving approaches for psychological support and clinical management. Furthermore, providing insights into these first-hand experiences to women considering planned OC, healthcare professionals, and policymakers could help establish systems to support the decision-making process.

Knowledge, Attitudes, and Perceptions of Women of Reproductive Age Regarding Fertility and Elective Oocyte Cryopreservation: A Study from the Al-Qassim Region

BACKGROUND

Oocyte cryopreservation is used for fertility preservation, medical reasons, and social reasons to overcome physiological decline in fertility with age. There was no research to find the knowledge, attitude, and perception of women regarding oocyte cryopreservation in our region. This study thus aimed to investigate the knowledge, attitudes, and perceptions of women of reproductive age in Al-Qassim, Saudi Arabia, regarding fertility and elective oocyte cryopreservation.

METHODS

An Arabic-language online survey was conducted over six months targeting women aged 18-45 years in the Al-Qassim region. A total of 612 participants completed the questionnaire, which covered topics such as reproductive aspirations, knowledge of fertility, knowledge of elective oocyte cryopreservation, and concerns regarding fertility preservation. Data analysis was performed using IBM SPSS Statistics for Windows, Version 21.0 (Released 2012; IBM Corp., Armonk, New York, United States).

RESULTS

The majority of participants (47.1%) were aged 18-25 years. Participants' perceptions towards fertility preservation and social egg freezing were mixed, indicating varying levels of awareness about fertility issues. A statistically significant relationship was found between education level and knowledge of oocyte cryopreservation (p-value=0.004). Women with higher education levels (bachelor's, master's, and PhD degrees) demonstrated significantly greater knowledge (p-value=0.004) about oocyte cryopreservation compared to those with lower education levels. The study highlights the influence of educational attainment on knowledge of oocyte cryopreservation.

CONCLUSION

These findings align with broader trends in health education, suggesting that higher educational attainment correlates with better fertility health literacy. Enhancing fertility health literacy through educational programs may lead to more proactive health behaviours and better awareness about available assisted reproductive technologies.

The Low Survivability of Transplanted Gonadal Grafts: The Impact of Cryopreservation and Transplantation Conditions on Mitochondrial Function

Advances in tissue preservation techniques have allowed reproductive medicine and assisted reproductive technologies (ARTs) to flourish in recent years. Because radio- and chemotherapy procedures are often gonadotoxic, irreversible damage can preclude future gamete production and endocrine support. Accordingly, in recent years, the freezing and storage of gonadal tissue fragments prior to the first oncological treatment appointment and autologous transplantation post-recovery have been considered improved solutions for fertility recovery in cancer survivors. Nevertheless, the cryopreservation and transplantation of thawed tissues is still very limited, and positive outcomes are relatively low. This review aims to discuss the limitations of oncofertility protocols with a focus on the impacts of mitochondrial dysfunction, oxidative stress, and the loss of antioxidant defense in graft integrity.

International attitudes towards medical and planned oocyte cryopreservation

PURPOSE

This study aims to better understand the knowledge and attitudes of men and women internationally towards oocyte cryopreservation (OC).

METHODS

An online 25-question survey was distributed internationally via email and social media. Knowledge and attitudes towards OC among different regions and genders were assessed. The study population consisted of adults from North America (NA, 15.7%), Southeastern and Eastern Europe (SE, 34.7%), Central and Western Europe (CWE, 12.7%), Asia (12.7%), and Middle East (ME, 8.9%).

RESULTS

A total of 496 respondents initiated the survey and the completion rate was 80.2%. The mean (SD) age was 35.2 (12.1) years. Over 70% were aware of OC, but only 4.8% had previously undergone the procedure. Most considered ages 26-31 as optimal for OC and correctly identified conditions that could impact the chance of spontaneous conception. Significant differences were observed regarding etiologies that would render OC acceptable. Only in NA and ME did solid majorities strongly agree that it is acceptable to proceed with OC to allow more time to find the right partner or for professional opportunities. More similar opinions were observed between genders. When medical conditions existed, large majorities across all nationalities and genders strongly agreed that OC is acceptable. In NA, SE, and ME most respondents would consider or recommend OC for any reason, whereas most respondents in CWE and Asia would do that only for certain social reasons or medical necessity.

CONCLUSION

A good understanding of OC was observed. Nationality appeared to impact opinions on appropriate indications for this procedure, though overall positive attitudes were documented.

New Approach to the Cryopreservation of GV Oocytes and Cumulus Cells through the Lens of Preserving the Intercellular Gap Junctions Based on the Bovine Model

Differences in structural and functional properties between oocytes and cumulus cells (CCs) may cause low vitrification efficiency for cumulus-oocyte complexes (COCs). We have suggested that the disconnection of CCs and oocytes in order to further cryopreservation in various ways will positively affect the viability after thawing, while further co-culture in vitro will contribute to the restoration of lost intercellular gap junctions. This study aimed to determine the optimal method of cryopreservation of the suspension of CCs to mature GV oocytes in vitro and to determine the level of mRNA expression of the genes (GJA1, GJA4; BCL2, BAX) and gene-specific epigenetic marks (DNMT3A) after cryopreservation and in vitro maturation (IVM) in various culture systems. We have shown that the slow freezing of CCs in microstraws preserved the largest number of viable cells with intact DNA compared with the methods of vitrification and slow freezing in microdroplets. Cryopreservation caused the upregulation of the genes Cx37 and Cx43 in the oocytes to restore gap junctions between cells. In conclusion, the presence of CCs in the co-culture system during IVM of oocytes played an important role in the regulation of the expression of the intercellular proteins Cx37 and Cx43, apoptotic changes, and oocyte methylation. Slow freezing in microstraws was considered to be an optimal method for cryopreservation of CCs.

Fertility preservation: knowledge, awareness, and attitude of university students and professors

BACKGROUND

Delayed pregnancy is a worldwide trend, especially in Western countries. University students and professors are at high risk of presenting age-related reproductive difficulties due to this new reproductive profile. Thus, through this study, we aimed at exploring the knowledge, awareness, and attitude of university students and professors related to fertility and fertility preservation (FP).

METHODS

We adopted a prospective cross-sectional study design and included students and professors from private university located in the Northeast of Brazil. Eligible participants (male and female) were invited through an online message. The participants accessed the online questionnaire through a link.

RESULTS

We performed 256 surveys (100 students and 156 professors). The overall mean age of participants was 35.8±13.1 years (from 18 to 67 years). Fertility was considered relevant by all participants, being very important among a greater number of students compared to professors, 61% versus 30.1%, P<0.001, respectively. The main reasons why participants could have postponed parenthood were reach financial stability (62.1%), career building (51.2%), health issues (37.9%), and not having a partner (33.9%). Students demonstrated a better understanding of FP and highlighted the importance of the age of females at the time of the oocyte cryopreservation. Very few students and professors already discussed reproductive planning with a health professional.

CONCLUSIONS

We observed a deficiency in the knowledge of Brazilian university students and professors about female fertility and FP options. Thus, exposing the population to information related to FP should be hyped in the university environment.

Exploring the Landscape of Social Egg Freezing: Navigating Medical Advancements, Ethical Dilemmas, and Societal Impacts

This narrative review article comprehensively explores the multifaceted landscape of social egg freezing, delving into its medical, ethical, societal, psychological, legal, and cultural dimensions. Oocyte cryopreservation, a developing procedure, gives women the chance to match their life goals with fertility goals. Informed decision-making, morally sound guidance, and open communication are all stressed by ethical considerations. Family planning practices, workplace cultures, and gender equality all have an impact on societal dynamics. The process's emotional toll and associated coping mechanisms are highlighted by psychological elements. Legal and policy frameworks need constant ethical reflection and understanding of the regulatory environment. Religious and cultural views highlight the variety of perspectives that influence attitudes toward this practice. For responsible practice to ensure individual liberty while navigating the evolving landscape of reproductive options, it is essential to comprehend how these aspects interact.

Perfusion and Ultrasonication Produce a Decellularized Porcine Whole-Ovary Scaffold with a Preserved Microarchitecture

The application of decellularized scaffolds for artificial tissue reconstruction has been an approach with great therapeutic potential in regenerative medicine. Recently, biomimetic ovarian tissue reconstruction was proposed to reestablish ovarian endocrine functions. Despite many decellularization methods proposed, there is no established protocol for whole ovaries by detergent perfusion that is able to preserve tissue macro and microstructure with higher efficiency. This generated biomaterial may have the potential to be applied for other purposes beyond reproduction and be translated to other areas in the tissue engineering field. Therefore, this study aimed to establish and standardize a protocol for porcine ovaries' decellularization based on detergent perfusion and ultrasonication to obtain functional whole-ovary scaffolds. For that, porcine ovaries (n = 5) were perfused with detergents (0.5% SDS and 1% Triton X-100) and submitted to an ultrasonication bath to produce acellular scaffolds. The decellularization efficiency was evaluated by DAPI staining and total genomic DNA quantification. ECM morphological evaluation was performed by histological, immunohistochemistry, and ultrastructural analyses. ECM physico-chemical composition was evaluated using FTIR and Raman spectroscopy. A cytocompatibility and cell adhesion assay using murine fibroblasts was performed. Results showed that the proposed method was able to remove cellular components efficiently. There was no significant ECM component loss in relation to native tissue, and the scaffolds were cytocompatible and allowed cell attachment. In conclusion, the proposed decellularization protocol produced whole-ovaries scaffolds with preserved ECM composition and great potential for application in tissue engineering.

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.

State of the art in assisted reproductive technologies for patients with advanced maternal age

According to the World Health Organization, the female reproductive age lasts up to 49 years, but problems with the realization of women's reproductive rights may arise much earlier. Significant numbers of factors affect the state of reproductive health: socioeconomic, ecological, lifestyle features, the level of medical literacy, and the state of the organization and medical care quality. Among the reasons for fertility decline in advanced reproductive age are the loss of cellular receptors for gonadotropins, an increase in the threshold of sensitivity of the hypothalamic-pituitary system to the action of hormones and their metabolites, and many others. Furthermore, negative changes accumulate in the oocyte genome, reducing the possibility of fertilization, normal development and implantation of the embryo and healthy offspring birth. Another theory of ageing causing changes in oocytes is the mitochondrial free radical theory of ageing. Taking into account all these age-related changes in gametogenesis, this review considers modern technologies aimed at the preservation and realization of female fertility. Among the existing approaches, two main ones can be distinguished: methods allowing the preservation of reproductive cells at a younger age using ART intervention and cryobanking, as well as methods aimed at improving the basic functional state of advanced-age women's oocytes and embryos.

Industrial Biotechnology Conservation Processes: Similarities with Natural Long-Term Preservation of Biological Organisms

Cryopreservation and lyophilization processes are widely used for conservation purposes in the pharmaceutical, biotechnological, and food industries or in medical transplantation. Such processes deal with extremely low temperatures (e.g., -196 °C) and multiple physical states of water, a universal and essential molecule for many biological lifeforms. This study firstly considers the controlled laboratory/industrial artificial conditions used to favor specific water phase transitions during cellular material cryopreservation and lyophilization under the Swiss progenitor cell transplantation program. Both biotechnological tools are successfully used for the long-term storage of biological samples and products, with reversible quasi-arrest of metabolic activities (e.g., cryogenic storage in liquid nitrogen). Secondly, similarities are outlined between such artificial localized environment modifications and some natural ecological niches known to favor metabolic rate modifications (e.g., cryptobiosis) in biological organisms. Specifically, examples of survival to extreme physical parameters by small multi-cellular animals (e.g., tardigrades) are discussed, opening further considerations about the possibility to reversibly slow or temporarily arrest the metabolic activity rates of defined complex organisms in controlled conditions. Key examples of biological organism adaptation capabilities to extreme environmental parameters finally enabled a discussion about the emergence of early primordial biological lifeforms, from natural biotechnology and evolutionary points of view. Overall, the provided examples/similarities confirm the interest in further transposing natural processes and phenomena to controlled laboratory settings with the ultimate goal of gaining better control and modulation capacities over the metabolic activities of complex biological organisms.

A Federated Blockchain Approach for Fertility Preservation and Assisted Reproduction in Smart Cities

Modern life is making people infertile. Giving birth later in life is wreaking havoc on our fertility and threatening human survival. Smart cities intend to optimize the quality of life of their citizens by utilizing technology for smarter living. This research first identifies the requirements and business opportunities of using advanced technology for smarter fertility preservation and assisted reproduction in smart cities. A federated blockchain approach is proposed for the alliance of integrated commercial egg banks (ICEBs). In particular, we designed a membership fee rebate (MFR) mechanism that offers incentives for blockchain creations in the egg banking alliance. We formulated the MFR problem into a leader–followers Stackelberg game whose objectives are (1) to maximize the benefits of forming the alliance (the leader) and (2) to maximize the benefits in each ICEB (the follower). We developed an iterative scheme that utilizes mathematical programming techniques to solve the two-level, Stackelberg game problem. With a given set of parameters of the alliance and membership fee function, and the average number of blocks generated for an oocyte, the iterative scheme achieves the optimal solution for the MFR rate per block created. A numerical example demonstrates the feasibility and applicability of the proposed iterative scheme. Numerical results show that it achieves good solutions in adding a small to medium-sized new ICEB to the existing alliance. The proposed federated approach lays the foundation for developing a blockchain-based egg banking platform.