Oocyte vitrification for elective fertility preservation: the past, present, and future

Oocytes on ice: Exploring the advancements in elective egg freezing for women

Introduction

Female fecundity decreases significantly after the age of 32, and rapidly so after age 37. There is no treatment to prevent this decline. Furthermore, globally, women are getting married later and the age at which they have their first child is increasing. As of July 2023, elective egg freezing (EEF) or oocyte cryopreservation (OC) for age-related fertility decline, commenced in Singapore. With medical advancements in OC, EEF is no longer considered experimental. The aim of this review is to examine the existing literature around EEF with regard to reproductive outcomes and its safety, to better guide clinicians in counselling young single women.

Method

Published studies were examined to increase understanding on optimal age for EEF, ideal number of oocytes for a live birth, recommended OC protocols, cryopreservation techniques affecting thaw survival or fertilisation, oocyte storage and pregnancy risks.

Results

Models predict that EEF should be performed at age <37 years and to achieve a 70% chance of live birth, women would need 14, 15 and 26 mature oocytes at ages 30-34, 35-37 and >38 years, respec-tively. An antagonist stimulation protocol with an agonist trigger would minimise ovarian hyper-stimulation syndrome and duration of stimulation without affecting outcomes. Oocyte vitrification in comparison to slow freezing increases thaw survival, fertilisation and clinical pregnancy rates. No increased risks exist for the woman, future pregnancy or child when compared with conventional IVF.

Conclusion

EEF is a viable option for single women desiring fertility preservation. Financial costs are significant, but returns are worthwhile if oocytes are utilised.

Planned Oocyte Cryopreservation: A Review of Current Evidence on Outcomes, Safety and Risks

Although oocyte cryopreservation was initially used as a fertility preservation strategy for medical indications, it is now is increasingly used to circumvent age-related infertility. Outcomes following planned oocyte vitrification, also known as elective egg freezing, are limited. Current studies show higher success rates for individuals undergoing fertility preservation treatment under age 35. Additionally, while freezing 20 oocytes is optimal to achieve pregnancy, freezing at least 8-10 oocytes is recommended. While fertility is not guaranteed, current evidence demonstrates that planned oocyte vitrification is an overall safe, low risk method of fertility preservation to reduce the risk for age-related infertility.

Oocyte vitrification for oncological and social reasons

The aim of this review is to present information related to oocyte cryopreservation, and particularly oocyte vitrification, performed to preserve fertility in oncologic and social indications. The success rates of oocyte cryopreservation have increased with the widespread use of the vitrification technique and are currently similar to those of in vitro fertilization performed with fresh oocytes. Vitrification is the most successful technique for oocyte cryopreservation. The most important factors that influence the success rate are the patient's age at the time of vitrification and the number of mature oocytes frozen. Thus, live birth rates differ for each age depending on the number of oocytes thawed and the freezing method. The American Society of Reproductive Medicine and the American Society of Clinical Oncology recommend presenting the option of oocyte cryopreservation for fertility preservation in cancer patients. Besides cancer patients, use of oocyte vitrification is increasing in women who wish to postpone pregnancy age and to have reproductive freedom with the development of the cryopreservation technique and the achievement of pregnancy rates similar to the use of fresh oocytes. Patients are provided consultancy service in terms of indication, the success rates by age, and the total number of oocytes frozen. It should be emphasized that this procedure is not a type of insurance policy for fertility, especially in elective oocyte cryopreservation.

Effect of male age on reproductive function: A comparison of young and middle-aged men

PURPOSE

There have been concerns regarding potential effects of older paternal age on male reproductive function. However, currently available data on this topic are insufficient and controversy exists. We analyzed semen characteristics and reproductive hormones in young men and middle-aged men to investigate the effect of age on male reproductive function.

MATERIALS AND METHODS

This study examined healthy males of reproductive age who visited a single infertility center from January 2016 to July 2021. The young group consisted of men who were less than 35 years-old, and the middle-age group consisted of men who were more than 45 years-old.

RESULTS

The two groups had no significant differences in sperm concentration ([89.9±59.4]×10⁶/mL vs. [104.4±82.1]×10⁶/mL, p=0.108) or sperm morphology (normal forms: 3.6%±1.5% vs. 3.4%±1.6%, p=0.131). However, the middle-age group had a smaller semen volume (3.2±1.5 mL vs. 2.5±1.4 mL, p<0.001), lower sperm motility (42.3%±9.8% vs. 31.2%±12.4%, p<0.001), lower progressive sperm motility (39.2%±10.3% vs. 28.4%±12.6%, p<0.001), and a higher serum follicle-stimulating hormone level.

CONCLUSIONS

Our results suggest that advanced male age might have a negative effect on fertility potential, as in women. This finding has important clinical implications because more couples are choosing to have children when they are older. Further studies on this issue, especially those that examine reproductive outcome, are warranted.

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.

Social Freezing: Pressing Pause on Fertility

Increasing numbers of women are undergoing oocyte or tissue cryopreservation for medical or social reasons to increase their chances of having genetic children. Social egg freezing (SEF) allows women to preserve their fertility in anticipation of age-related fertility decline and ineffective fertility treatments at older ages. The purpose of this study was to summarize recent findings focusing on the challenges of elective egg freezing. We performed a systematic literature review on social egg freezing published during the last ten years. From the systematically screened literature, we identified and analyzed five main topics of interest during the last decade: (a) different fertility preservation techniques, (b) safety of freezing, (c) usage rate of frozen oocytes, (d) ethical considerations, and (e) cost-effectiveness of SEF. Fertility can be preserved for non-medical reasons through oocyte, embryos, or ovarian tissue cryopreservation, with oocyte vitrification being a new and optimal approach. Elective oocyte cryopreservation is better accepted, supports social gender equality, and enhances women's reproductive autonomy. Despite controversies, planned oocyte cryopreservation appears as a chosen strategy against age-related infertility and may allow women to feel that they are more socially, psychologically, and financially stable before motherhood.

Oocyte Biobanks: Old Assumptions and New Challenges

The preservation of fertility is a clinical issue that has been emerging considerably in recent decades, as the number of patients of childbearing age who risk becoming infertile for many reasons is increasing. The cryopreservation technique of oocytes has been developed for many years and nowadays constitutes a method of safe storage with impressive efficacy and high rates of successful thawing. The storage and use for research of oocytes taken for medical or non-medical can be carried out by both public and private structures, through egg sharing, voluntary egg donation and so-called “social freezing” for autologous use. This paper focuses on the oocyte bank as an emerging cryopreservation facility, in which a collaboration between public and private and the creation of a network of these biobanks can be useful in enhancing both their implementation and their functions. Good oocyte biobank practice would require that they be collected, stored, and used according to appropriate bioethical and bio-law criteria, collected and stored according to procedures that guarantee the best preservation of their structural components and a high level of safety, connected with appropriate procedures to protect the rights and privacy of the parties involved and associated with the results of the bio-molecular investigations that will be carried out gradually.

Fertility education: what's trending on Instagram

Objective

To determine the prevalence, authorship, and types of fertility-related information shared on Instagram targeted toward a new patient interested in fertility options using hashtag and content analysis. Secondary outcomes included comparison of post content stratified by author type (physicians versus patients).

Methods

A list of ten hashtags consisting of fertility terms for the new patient was derived. Content analysis was performed in April 2019 on the top 50 and most recent 50 posts for each hashtag to determine authorship and content type. The distribution of fertility terms in posts made by physicians was compared to that of patients and differences in use of terms were analyzed.

Results

Our search yielded 3,393,636 posts. The two most popular hashtags were IVF (N = 912,049), and Infertility (N = 852,939). Authorship of the top posts for each hashtag (N = 1000) were as follows: patients (67 %), physicians (10 %), for-profit commercial groups (6.0 %), allied health professional (4.5 %), professional societies (1 %), and other (11 %). Of these posts, 60 % related to patient experiences, 10 % advertisements, 10 % outreach, and 8 % educational. Physicians were more likely to author posts related to oocyte cryopreservation compared to IVF, while patients were more likely to author posts about IVF (p < 0.0001).

Conclusions

Over 3 million posts related to fertility were authored on Instagram. A majority of fertility posts are being mobilized by patients to publicly display and share their personal experiences. Concurrent with the rising utilization of planned oocyte cryopreservation, there is a trend toward physicians educating their patients about the process using social media as a platform. Physician participation on social media may offer a low-cost platform for networking and connecting with patients. Future studies examining the educational quality of posts by author type should be explored.

Social egg freezing and donation: waste not, want not

The trend towards postponement of childbearing has seen increasing numbers of women turning towards oocyte banking for anticipated gamete exhaustion (AGE banking), which offers a realistic chance of achieving genetically connected offspring. However, there are concerns around the use of this technology, including social/ethical implications, low rate of utilisation and its cost-effectiveness. The same societal trends have also resulted in an increased demand and unmet need for donor oocytes, with many women choosing to travel overseas for treatment. This has its own inherent social, medical, financial and psychological sequelae. We propose a possible pathway to address these dual realities. The donation of oocytes originally stored in the context of AGE banking, with appropriate compensatory mechanisms, would ameliorate AGE banking concerns, while simultaneously improving the supply of donor oocytes. This proposed arrangement will result in tangible benefits for prospective donors, recipients and society at large.

Expert consensus for primary management of reproductive health: a Delphi study

BACKGROUND

The main barrier for an appropriate primary management of the reproductive health was lack of knowledge about the risk factors and prevention measures for infertility and the main recommendations was to involve primary care physicians in reproductive health.

AIMS

To reach a consensus around barriers and enablers for appropriate primary management of the reproductive health.

METHODS

An observational study was performed using the modified Delphi technique, from October 2017 to April 2018 in private and public assisted reproduction clinics in Spain. A questionnaire consisted of 58 items, divided into four blocks to explore consensus among a group of experts by synthesizing opinions.

RESULTS

In the first Delphi round, the response rate was 50% and panelists reached a 72.4% of consensus. In second round, the response rate was 55% and panelists reached a 25% of consensus. To minimize limitations related to the use of a structured questionnaire, a space for free text responses was provided. The following items yielded unanimous agreement: "It is necessary to promote reproductive planning-not just contraception-from secondary school," "The media should not trivialize pregnancies in women aged over 50," "Postponing family formation is the main cause of the increase in assisted reproduction treatments in Spain," and "Postponing motherhood implies an inherently decreased probability of having children."

CONCLUSIONS

These recommendations could set the basis for a public health action plan for primary management of reproductive health. The findings may be applicable to any country whose health services system provides primary healthcare.

Is there a correlation between paternal age and aneuploidy rate? An analysis of 3,118 embryos derived from young egg donors

OBJECTIVE

To investigate a possible correlation between chromosomal aberrations and paternal age, analyzing embryos derived from young oocyte donors, with available preimplantation genetic testing for aneuploidy results from day 5/6 trophectoderm biopsy obtained by next-generation sequencing for all 24 chromosomes.

DESIGN

Retrospective cohort study.

SETTING

Canadian fertility centre.

PATIENT(S)

A total of 3,118 embryos from 407 male patients, allocated into three paternal age groups: group A, ≤39 years (n = 203); group B, 40-49 years (n = 161); group C, ≥50 years (n = 43).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcomes were aneuploidy, euploidy, mosaicism, and blastocyst formation rates. Secondary endpoints were comparison of specific chromosome aneuploidy, segmental and complex (involving two chromosomes + mosaicism >50%) aneuploidy, and analysis of overall percentage of chromosomal gains and losses within each group.

RESULT(S)

The study included 437 in vitro fertilization (IVF) antagonist cycles using 302 oocyte donors in which preimplantation genetic testing for aneuploidy was performed. Overall, 70.04% of embryos were euploid, 13.9% were aneuploid, and 16.06% were mosaic. No significant differences among paternal age groups A, B, and C were found in euploidy rates (69.2%, 70.6%, 71.4%, respectively), aneuploidy rates (14.7%, 12.8%, 13.9%, respectively) or mosaicism rates (16.1%, 16.6%, 13.6%; respectively). The fertilization rate was lower in group C compared with group B (76.35% vs. 80.09%). No difference was found in blastocyst formation rate between the study groups (median 52% [interquartile range, 41%, 67%] vs. 53% [42%, 65%] vs. 52% [42%, 64%], respectively). A generalized linear mixed model regression analysis for embryo ploidy rates found older oocyte donor age to be independently associated with embryo aneuploidy (odds ratio = 1.041; 95% CI, 1.009-1.074). The rate of segmental aneuploidies was significantly higher in the older versus younger paternal age group (36.6% vs. 19.4%).

CONCLUSION(S)

No association was found between paternal age and aneuploidy rates in embryos derived from IVF cycles using young oocyte donors, after adjusting for donor, sperm, and IVF cycle characteristics. Advanced paternal age ≥ 50, compared with younger paternal ages, was associated with a lower fertilization rate and increased rate of segmental aberrations.

Blastocyst mitochondrial DNA (mtDNA) is not affected by oocyte vitrification: a sibling oocyte study

PURPOSE

To evaluate whether mtDNA content at the blastocyst stage differs between embryos derived from fresh or vitrified sibling oocytes.

MATERIAL AND METHODS

A retrospective analysis was performed between March 2017 and September 2018, including 504 blastocysts from 94 couples undergoing preimplantation genetic testing for aneuploidies (PGT-A), using fresh oocytes together with previously vitrified oocytes. Trophectoderm biopsies were performed and subjected to next generation sequencing.

RESULTS

On average, 1.8 ± 1.0 oocyte vitrification cycles were performed per patient. Between fresh and vitrified cycles, no difference was observed between the number of fertilized oocytes (5.3 ± 4.2 versus 5.5 ± 3.0). Blastulation rate on day 5 per fertilized oocyte was significantly higher in the fresh group (62% ± 29% versus 44% ± 31%; p < 0.001). For the 504 biopsied blastocysts, 294 fresh versus 210 vitrified, no significant differences were found in the euploid rate, 40.5% versus 38.6% (p = 0.667), and mtDNA content, 30.1 (± 10.6) versus 30.0 (± 12.5) (p = 0.871), respectively. Regardless of the origin of the oocytes, aneuploid blastocysts contained significantly higher mtDNA values compared with the euploid ones (31.4 versus 28.0; p = 0.001). Furthermore, top-quality blastocysts had a significantly lower mtDNA content compared with moderate and poor-quality blastocysts (p < 0.001) and blastocysts biopsied on day 5 showed significantly lower mtDNA content compared with day 6 or day 7 blastocysts (p < 0.001). However, when analyzing the blastocyst mtDNA content according to the ploidy state, no differences were found for blastocyst quality or day of biopsy between blastocysts originating from fresh or vitrified oocytes.

CONCLUSION

Oocyte vitrification does not affect the mtDNA content of trophectoderm biopsies.

Anti-Müllerian hormone is an independent marker for oocyte survival after vitrification

RESEARCH QUESTION

This study explored the relationship between anti-Müllerian hormone (AMH) and oocyte survival after vitrification. The association between AMH and blastocyst formation after oocyte vitrification was also assessed.

DESIGN

A retrospective observational analysis was performed in a private IVF centre. A total of 4507 metaphase-II warmed oocytes were included from 450 couples, predominantly of Arab ethnicity. Between August 2015 and August 2018, couples underwent 484 intracytoplasmic sperm injection (ICSI) treatments using vitrified-warmed oocytes.

RESULTS

Patients' median age ± SD was 36.2 ± 6.1 years, AMH concentration 2.6 ± 3.4 ng/ml and body mass index (BMI) 26.5 ± 4.6 kg/m². The oocyte survival rate after vitrification was 87.37 ± 20.42%. AMH concentration showed a significant correlation (Kendall's tau 0.087, P = 0.0079) with oocyte survival rate independent of oocyte yield. Correlation was significant (odds ratio 1.041, 95% confidence interval 1.007-1.077, P = 0.018) when a multivariant model was applied that included AMH, age and BMI. The receiver operating characteristic curve showed an AMH cut-off value of 1.09 ng/ml that could obtain at least a 70% survival rate, with an area under the curve of 0.669. Regarding embryo development in ICSI cycles including fresh and warmed oocytes for the same patient, blastocyst formation rate was higher in fresh compared with warmed oocytes (P < 0.001). In this subgroup no significant correlation was seen between fertilization or blastocyst rate and AMH concentration.

CONCLUSIONS

AMH concentration showed a significant correlation with oocyte survival. Blastocyst formation was significantly lower after oocyte vitrification, but no correlation was found with AMH. Clinicians should carefully evaluate oocyte vitrification for patients with AMH below 1.09 ng/ml and consider embryo accumulation for these patients in preference to oocyte accumulation.

Abrahamic traditions and egg freezing: Religious Women's experiences in local moral worlds

In this article, we elucidate how elective egg freezing (EEF) has been received within the three Abrahamic traditions-Judaism, Christianity, and Islam-and how these religion-specific standpoints have affected the EEF experiences of women who self-identify as religiously observant. Through an analysis of religious women's narratives, the study explores the "local moral worlds" of religious women who chose to freeze their eggs for non-medical reasons. It draws on ethnographic interviews with 14 women in the United States and Israel who had completed at least one EEF cycle, and who were part of a large, binational study that interviewed, between 2014 and 2016, 150 women who pursued EEF. These religious women, who were all highly educated, faced a particular challenge in finding appropriate marriage partners. Feeling pressured but still hopeful to marry and create large families, the women used EEF to extend their reproductive timelines and reduce their anxieties. As the study showed, the women reinterpreted or reconciled religious restrictions on the use of EEF in various ways, believing that their ultimate pursuit of religiously sanctioned reproduction justified the means. This study, which is the first to compare Jewish, Christian, and Muslim women's experiences of EEF, illustrates how this novel technology is now shaping the local moral worlds of religious women.

Evaluation of the effect of the elective blastocyst-stage embryo transfer and freezing strategy on the abandonment of frozen embryos under the Taiwan National Assisted Reproduction Act

Purpose

To evaluate the relationship between elective blastocyst transfer, freezing strategy, and the abandonment of frozen embryos with a storage time limit of 10 years as specified in the National Assisted Reproduction Act of Taiwan.

Methods

This two-phase retrospective cohort study was conducted at a single tertiary center, Kaohsiung Chang Gung Memorial Hospital (KCGMH), in 2019. Participants were selected from a data registry containing 4167 fresh IVF cycles, including phase 1 cycles from 1999 to 2009 and phase 2 cycles from 2010 to 2014, at KCGMH.

Results

In phase 1, embryo abandonment was associated with the production of more mature oocytes and embryos, the freezing of more embryos, young female age, blastocyst transfer, and positive pregnancy results. After adjustment for confounding factors, only positive pregnancy results (adjusted odds ratio [aOR] 4.38, 95% confidence interval [CI] 3.17, 6.04), the freezing of ≥ 2 embryos (aOR 3.68, 95% CI 3.10, 4.38), the production of ≥ 6 embryos (aOR 1.68, 95% CI 1.03, 2.73), and the use blastocyst transfer (aOR 2.46, 95% CI 1.64, 3.69) remained significantly associated with embryo abandonment. The factors associated with embryo abandonment or possible abandonment were similar in phase 2.

Conclusion

For elective blastocyst stage transfer and a freezing strategy performed according to the Taiwan National Assisted Reproduction Act, a young female age ≤ 35 with positive pregnancy status due to the original IVF treatment, the production of ≥ 6 embryos, and the cryopreservation of ≥ 2 blastocysts may increase the likelihood of abandoning embryos in the future.

Elective egg freezing and male support: a qualitative study of men's roles in women's fertility preservation

How do men participate in women's fertility preservation decisions and procedures? This binational, qualitative study assessed whether men play supportive roles either before, during or after women's elective egg freezing (EEF) cycles. From June 2014 to August 2016, 150 women (114 in the USA and 36 in Israel) who had completed at least one cycle of EEF were interviewed by two medical anthropologists, one in each country. The majority (85%) of women in the study identified the lack of a male partner as their main reason for pursuing EEF. However, nearly two-thirds (63%) of women relied on some form of male support during their EEF decision making processes and procedures. Five categories of men, in order of support, included: (i) fathers (or other male father figures), (ii) male partners (past or present), (iii) male friends, (iv) brothers and (v) male judges (some of whom supported EEF in divorce settlements). More than a dozen different forms of assistance were offered by men in four major categories: (i) instrumental, (ii) financial, (iii) physical and (iv) psychological. Although one-third (37%) of women went through EEF alone or with only female support, this study reveals the 'hidden' roles men play in supporting the reproductive aspirations of women.

Preserving fertility in female patients with hematological malignancies: a multidisciplinary oncofertility approach

Oncofertility is a new interdisciplinary field at the intersection of oncology and reproductive medicine that expands fertility options for young cancer patients. The most common forms of hematological malignancies that occur in girls and young women and therefore necessitate oncofertility care are acute lymphocytic leukemia, acute myeloid leukemia, non-Hodgkin's lymphoma, and Hodgkin's lymphoma. Aggressive gonadotoxic anticancer regimens including alkylating chemotherapy and total body irradiation are used often in treating girls and young women with hematological malignancies. The risks of gonadotoxicity and subsequent iatrogenic premature ovarian insufficiency and fertility loss depend mainly on the type and stage of the disease, dose of anticancer therapy as well as the age of the patient at the beginning of treatment. To avoid or at least mitigate the devastating complications of anticancer therapy-induced gonadotoxicity, effective and comprehensive strategies that integrate different options for preserving and restoring fertility ranging from established to experimental strategies should be offered before, during, and after chemotherapy or radiotherapy. A multidisciplinary approach that involves strong coordination and collaboration between hemato-oncologists, gynecologists, reproductive biologists, research scientists, and patient navigators is essential to guarantee high standard of care.

Dynactin pathway-related gene expression is altered by aging, but not by vitrification

The storage of surplus oocytes by cryopreservation (OC) is a widely used tool in assisted reproductive technology, but there is a great debate about the effects of cryopreservation on oocyte competence. It is known that OC may affect meiotic spindles but remains unclear if OC may increase the risk of aneuploidy. The aim of this study was to test the effects of OC and women aging on the expression of cytokinesis-related genes playing an important role in the segregation of chromosomes (DCTN1, DCTN2, DCTN3, DCTN6 and PLK1). Results highlighted that OC do not modify the expression of the selected genes, whereas women aging modulate the expression of all transcripts, confirming that aging is the crucial factor affecting meiosis and aneuploidy risk. A new role for Dynactin and PLK1 was shed in light, providing information on the ageing process in the oocyte which may be associated to reduced fertility.

Patient-centered elective egg freezing: a binational qualitative study of best practices for women's quality of care

PURPOSE

How can elective egg freezing (EEF) be made patient centered? This study asked women to reflect on their experiences of EEF, which included their insights and recommendations on the optimal delivery of patient-centered care.

METHODS

In this binational, qualitative study, 150 women (114 in the USA, 36 in Israel) who had completed at least one cycle of EEF were recruited from four American IVF clinics (two academic, two private) and three in Israel (one academic, two private) over a two-year period (June 2014-August 2016). Women who volunteered for the study were interviewed by two medical anthropologists. Interviews were audio recorded, transcribed, and entered into a qualitative data management program (Dedoose) for analysis.

RESULTS

The majority (85%) of women were without partners at the time of EEF, and thus were undertaking EEF alone in mostly couples-oriented IVF clinics. Following the conceptual framework known as "patient-centered infertility care," we identified two broad categories and eleven specific dimensions of patient-centered EEF care, including (1) system factors: information, competence of clinic and staff, coordination and integration, accessibility, physical comfort, continuity and transition, and cost and (2) human factors: attitude and relationship with staff, communication, patient involvement and privacy, and emotional support. Cost was a unique factor of importance in both countries, despite their different healthcare delivery systems.

CONCLUSIONS

Single women who are pursuing EEF alone in the mostly couples-oriented world of IVF have distinct and multifaceted needs. IVF clinics should strive to make best practices for patient-centered EEF care a high priority.

Knowledge and decision making about future fertility and oocyte cryopreservation among young women

The objective was to examine what young graduate student women know about preserving fertility/oocyte cryopreservation, and which reproductive resources they use. A prospective, cross-sectional design was used and the study was conducted at a University on the East Coast of the United States. The participants were 278 female graduate students. Participants completed a survey with questions about demographics, fertility knowledge, oocyte cryopreservation, and sources of fertility information. Descriptive statistics were calculated for all variables. Participants had average knowledge about fertility (64% items correct). The most used fertility information source was formal education (87.1%), information to help make fertility decisions was gynaecologists (85.3%), and oocyte cryopreservation was media (63.4%). Only 26.6% reported being well informed about fertility. Although 93.9% had heard of oocyte cryopreservation, only 7.2% had considered its use. Most (74.9%) ranked fertility as important, though 83% would consider postponing family until career (85.2%) and relationship (85.2%) were established. Half felt that there was a social stigma surrounding oocyte cryopreservation, and 70.1% believed that the media gives the impression that motherhood is viable after 40 years old. Professionally motivated women receive the most information about fertility from formal, accuracy-driven sources (i.e. education, healthcare providers), but information about fertility preservation from media. They lack knowledge about fertility planning.

Advanced Maternal Age in IVF: Still a Challenge? The Present and the Future of Its Treatment

Advanced maternal age (AMA; >35 year) is associated with a decline in both ovarian reserve and oocyte competence. At present, no remedies are available to counteract the aging-related fertility decay, however different therapeutic approaches can be offered to women older than 35 year undergoing IVF. This review summarizes the main current strategies proposed for the treatment of AMA: (i) oocyte cryopreservation to conduct fertility preservation for medical reasons or "social freezing" for non-medical reasons, (ii) personalized controlled ovarian stimulation to maximize the exploitation of the ovarian reserve in each patient, (iii) enhancement of embryo selection via blastocyst-stage preimplantation genetic testing for aneuploidies and frozen single embryo transfer, or (iv) oocyte donation in case of minimal/null residual chance of pregnancy. Future strategies and tools are in the pipeline that might minimize the risks of AMA through non-invasive approaches for embryo selection (e.g., molecular analyses of leftover products of IVF, such as spent culture media). These are yet challenging but potentially ground-breaking perspectives promising a lower clinical workload with a higher cost-effectiveness. We also reviewed emerging experimental therapeutic approaches to attempt at restoring maternal reproductive potential, e.g., spindle-chromosomal complex, pronuclear or mitochondrial transfer, and chromosome therapy. In vitro generation of gametes is also an intriguing challenge for the future. Lastly, since infertility is a social issue, social campaigns, and education among future generations are desirable to promote the awareness of the impact of age and lifestyle habits upon fertility. This should be a duty of the clinical operators in this field.

Ten pathways to elective egg freezing: a binational analysis

PURPOSE

What are the specific pathways that lead women to freeze their eggs? In this binational study, women were asked directly about the life circumstances that led them on the path to elective egg freezing (EEF).

METHODS

From June 2014 to August 2016, 150 women (114 in the USA, 36 in Israel) who had completed at least 1 cycle of EEF were interviewed by two medical anthropologists. Study participants were recruited through four American IVF clinics (two academic, two private) and three in Israel (one academic, two private). Interviews were audio-recorded, transcribed verbatim, and entered into a qualitative data management program (Dedoose) for analysis.

RESULTS

The majority (85%) of women in the study were without partners, while 15% had partners at the time of EEF. Six pathways to EEF were found among women without partners (being single, divorced, broken up, deployed overseas, single mother, career planner), with career planning being the least common pathway to EEF. Among women with partners, four pathways to EEF were found (relationship too new or uncertain, partner not ready to have children, partner refusing to have children, or partner having multiple partners). With only one exception, the pathways and their frequencies were similar in both countries.

CONCLUSIONS

Partnership problems, not career planning, lead most women on pathways to EEF. These pathways should be studied in a variety of national settings, and fertility clinics should offer patient-centered care for single women pursuing EEF in the couples-oriented world of IVF.

Elective egg freezing and its underlying socio-demography: a binational analysis with global implications

BACKGROUND

What are the underlying socio-demographic factors that lead healthy women to preserve their fertility through elective egg freezing (EEF)? Many recent reviews suggest that women are intentionally postponing fertility through EEF to pursue careers and achieve reproductive autonomy. However, emerging empirical evidence suggests that women may be resorting to EEF for other reasons, primarily the lack of a partner with whom to pursue childbearing. The aim of this study is thus to understand what socio-demographic factors may underlie women's use of EEF.

METHODS

A binational qualitative study was conducted from June 2014 to August 2016 to assess the socio-demographic characteristics and life circumstances of 150 healthy women who had undertaken at least one cycle of elective egg freezing (EEF) in the United States and Israel, two countries where EEF has been offered in IVF clinics over the past 7-8 years. One hundred fourteen American women who completed EEF were recruited from 4 IVF clinics in the US (2 academic, 2 private) and 36 women from 3 IVF clinics in Israel (1 academic, 2 private). In-depth, audio-recorded interviews lasting from 0.5 to 2 h were undertaken and later transcribed verbatim for qualitative data analysis.

RESULTS

Women in both countries were educated professionals (100%), and 85% undertook EEF because they lacked a partner. This "lack of a partner" problem was reflected in women's own assessments of why they were single in their late 30s, despite their desires for marriage and childbearing. Women themselves assessed partnership problems from four perspectives: 1) women's higher expectations; 2) men's lower commitments; 3) skewed gender demography; and 4) self-blame.

DISCUSSION

The "lack of a partner" problem reflects growing, but little discussed international socio-demographic disparities in educational achievement. University-educated women now significantly outnumber university-educated men in the US, Israel, and nearly 75 other societies around the globe, according to World Bank data. Thus, educated women increasingly face a deficit of educated men with whom to pursue childbearing.

CONCLUSION

Among healthy women, EEF is a technological concession to gender-based socio-demographic disparities, which leave many highly educated women without partners during their prime childbearing years. This information is important for reproductive specialists who counsel single EEF patients, and for future research on EEF in diverse national settings.

Is egg freezing a good response to socioeconomic and cultural factors that lead women to postpone motherhood?

In western societies, a growing number of women are currently turning to social egg freezing, a technique that makes it possible to freeze oocytes and thus preserve female reproductive possibilities. The current ethical debate has focused on normative aspects concerning the question of whether social egg freezing empowers women's reproductive autonomy. Due to this narrow focus on autonomy, deeper questions concerning the socio-economic conditions and cultural factors that lead women to delay reproduction, to feel pressured by their biological clock, and thus to consider social egg freezing have not yet received sufficient attention and analysis. The aim of this study was to broaden the ethical debate by focusing on whether social egg freezing is a good response to the socioeconomic and cultural constraints that lead women to postpone motherhood, and therefore whether it can be seen as a means of achieving what in virtue ethics is known as a 'good life'. I will argue that while social egg freezing can be seen as a means to empower women to adapt to current socioeconomic constraints, it is not an adequate response to cultural factors, as these cannot be solved by simply extending a woman's fertility.

Oocyte Cryopreservation for Fertility Preservation in Healthy Women

Advancements in methods of fertility preservation have resulted in more options available to women seeking to postpone reproduction. Preservation of unfertilized oocytes provides women with the possibility for reproduction even after age-related declines in fertility might make conceiving a child difficult to impossible. As oocyte cryopreservation rises in popularity among women, it is crucial for nurses and other clinicians to understand the background, process, ethical issues, and risks involved to help women make informed medical decisions.

Calcium ion regulation by BAPTA-AM and ruthenium red improved the fertilisation capacity and developmental ability of vitrified bovine oocytes

Vitrification reduces the fertilisation capacity and developmental ability of mammalian oocytes; this effect is closely associated with an abnormal increase of cytoplasmic free calcium ions ([Ca²⁺]i). However, little information about the mechanism by which vitrification increases [Ca²⁺]i levels or a procedure to regulate [Ca²⁺]i levels in these oocytes is available. Vitrified bovine oocytes were used to analyse the effect of vitrification on [Ca²⁺]i, endoplasmic reticulum Ca²⁺ (ER Ca²⁺), and mitochondrial Ca²⁺ (mCa²⁺) levels. Our results showed that vitrification, especially with dimethyl sulfoxide (DMSO), can induce ER Ca²⁺ release into the cytoplasm, consequently increasing the [Ca²⁺]i and mCa²⁺ levels. Supplementing the cells with 10 μM 1,2-bis (o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM or BAPTA) significantly decreased the [Ca²⁺]i level and maintained the normal distribution of cortical granules in the vitrified bovine oocytes, increasing their fertilisation ability and cleavage rate after in vitro fertilisation (IVF). Treating vitrified bovine oocytes with 1 μM ruthenium red (RR) significantly inhibited the Ca²⁺ flux from the cytoplasm into mitochondria; maintained normal mCa²⁺ levels, mitochondrial membrane potential, and ATP content; and inhibited apoptosis. Treating vitrified oocytes with a combination of BAPTA and RR significantly improved embryo development and quality after IVF.

Maintaining viability and characteristics of cholangiocarcinoma tissue by vitrification-based cryopreservation

Tumor tissue has great clinical and scientific value which relies highly on the proper preservation of primary materials. Conventional tumor tissue cryopreservation using slow-freezing method has yielded limited success, leading to significant cell loss and morphological damage. Here we report a standardized vitrification-based cryopreservation method, by which we have successfully vitrified and warmed 35 intrahepatic cholangiocarcinoma (ICC) tissues with up to 80% viability of the fresh tumor tissues. Cryopreserved ICC tissue could generate patient-derived xenografts (PDXs) with take rates of 68.2% compared to 72.7% using fresh tumor tissues. Histological and genetic analyses showed that no significant alterations in morphology and gene expression were introduced by this cryopreservation method. Our procedure may facilitate collection, long-time storage and propagation of cholangiocarcinoma or other tumor specimens for (pre)clinical studies of novel therapies or for basic research.