Postponing Pregnancy Through Oocyte Cryopreservation for Social Reasons: Considerations Regarding Clinical Practice and the Socio-Psychological and Bioethical Issues Involved

Planned oocyte cryopreservation: a systematic review and meta-regression analysis

BACKGROUND

Awareness of the age-related decline in fertility potential has increased the popularity of planned oocyte cryopreservation (POC). However, data regarding outcomes of POC, including rates of women returning to thaw oocytes, as well as pregnancy and live birth rates, are scarce and based mostly on small case series.

OBJECTIVE AND RATIONALE

POC was defined as cryopreservation exclusively for prevention of future age-related fertility loss. The primary outcome was live birth rate per patient. The secondary outcomes included the return to thaw rate and laboratory outcomes. A meta-regression analysis examining the association between live birth and age above 40 or below 35 was conducted.

SEARCH METHODS

We conducted a systematic database search from inception to August 2022. The search included PubMed (MEDLINE) and EMBASE. Our search strategies employed a combination of index terms (Mesh) and free text words to compile relevant concepts. The systematic review and meta-regression were undertaken following registration of systematic review (PROSPERO registration number CRD42022361791) and were reported following guidelines of Preferred Reporting Items for Systematic Review and Meta-Analyses 2020 (PRISMA 2020).

OUTCOMES

The database search yielded 3847 records. After the selection process, 10 studies, conducted from 1999 to 2020, were included. Overall, 8750 women underwent POC, with a mean cryopreservation age of 37.2 (±0.8). Of those, 1517 women returned to use their oocytes with a return rate of 11.1% (± 4.7%). The mean age at the time of cryopreservation for women who returned to use their oocytes was 38.1 (±0.4), with an average of 12.6 (±3.6) cryopreserved oocytes per woman. In a meta-analysis, the oocyte survival rate was 78.5% with a 95% CI of 0.74-0.83 (I2 = 93%). The live birth rate per patient was 28% with a 95% CI of 0.24-0.33 (I2 = 92%). Overall, 447 live births were reported. In a sub-group analysis, women who underwent cryopreservation at age ≥40 achieved a live birth rate per patient of 19% (95% CI 0.13-0.29, I2 = 6%), while women aged ≤35 years old or younger had a higher live birth rate per patient of 52% (95% CI 0.41-0.63, I2 = 7%).

WIDER IMPLICATIONS

POC emerges as a feasible option for women aiming to improve their chances of conceiving at a later reproductive age. Nonetheless, it must be acknowledged that the overall success rates of POC are limited and that the likelihood of successful live birth declines as the age at cryopreservation rises. With increasing interest in POC, the collation of comprehensive and high-quality data is imperative to clearly define the outcomes for various age groups.

REGISTRATION NUMBER

CRD42022361791.

Oocyte freezing intention for non-medical reasons: the interplay with childbearing intention, age and self efficacy

In recent years, the possibility for healthy women to consider or undertake oocyte freezing for non-medical reasons (OFNMR) allows women who want to have biological children, to enable motherhood at a later time, while protecting against age-related fertility decline. The present study explored the intended OFNMR among healthy Israeli women by looking at the interplay of age, childbearing intention and general self-efficacy - a personal resource. Two hundred fifty-one Israeli women were recruited through social networks and online forums related to women's issues in general. Participants completed self-report questionnaires addressing socio-demographic data, childbearing intention, general self-efficacy, and OFNMR intention. The results revealed that the association between women's age and OFNMR intention was insignificant. However, childbearing intention moderated the association between women's age and OFNMR intention. Specifically, the association between age and OFNMR intention was positive and significant for women with childbearing intention while for women without childbearing intention, it was negative and significant. General self-efficacy was not found to be associated with OFNMR intention. The current study shed light on the role of childbearing intention in the context of fertility decisions, especially among women who verbalize their intention for OFNMR. Routine discussion between health-care professionals and women regarding childbearing intentions is recommended, especially with women nearing age-related decline in fertility.

Mapping ethical, legal, and social implications (ELSI) of fertility preservation

RESEARCH QUESTION

The study examines the ethical, legal, and social implications of fertility preservation, highlighting its importance across oncofertility, elective egg freezing, and posthumous assisted reproduction, as well as its impact on transgender individuals undergoing gender-affirming surgeries.

DESIGN

A comprehensive analysis of 600 articles, focusing on a diverse range of disciplines, including bioethics, psychology, and sociology, to explore public and healthcare professionals' knowledge, patient experiences, and regulatory constraints.

RESULTS

The body of literature is growing, indicating increasing recognition of FP's significance. Key themes included the centrality of counseling and informed decision-making, especially in oncofertility and EEF, and ethical debates surrounding informed consent and the autonomy of involved individuals. The analysis underscored a western-centric bias in current research, emphasizing the need for more inclusive and culturally sensitive studies.

CONCLUSIONS

The study calls for a nuanced understanding of FP, advocating for policies that consider ethical, cultural, and social dimensions. It suggests the necessity for interdisciplinary research to address identified gaps, particularly in understanding non-Western perspectives and ensuring equitable access to FP services globally. Moreover, the review emphasizes the importance of integrating patient-centric approaches and ethical frameworks to guide FP practices and policies, ensuring they respect diverse values and meet individuals' needs.

Knowledge and beliefs about oocyte cryopreservation for medical and social reasons in female students: a cross-sectional survey

BACKGROUND

With the increasing number of young women surviving cancer and a growing trend among highly educated women to postpone childbearing for educational or professional pursuits, there is a rising demand for egg freezing services to ensure a successful pregnancy. This study aims to assess the knowledge and beliefs surrounding oocyte cryopreservation, both for medical and social reasons, among female students in Tehran, Iran.

METHODS

An online cross-sectional survey was carried out from March to August of 2022, involving a total of 1279 childless students pursuing master's and doctoral degrees at universities in Tehran. The participants were between the ages of 18 and 38. Knowledge and beliefs about medical and social oocyte cryopreservation were assessed through Fertility Preservation Survey (FPS) instrument.

RESULTS

The mean age of the participants was 26.38 ± 4.9. The majority of students expected to be "30-34 years" when they become pregnant with their first child (41.1%, M: 30.3 ± 4.13 years) and "35-39 years" when they give birth to their last child (46.7%, M: 35.28 ± 4.18 years). The students agreed with preserving fertility with medical (93.3%) and social (86.9%) indications and believed the medical (95.1%) and social (87.4%) costs of cryopreservation should be covered by the healthcare system. Among the participants, 75.6% considered cost to be a definite or probable factor in their decision to pursue fertility preservation. The oncology team's recommendation was identified as the most important factor in deciding on medical egg freezing (92.6%, M: 3.46 ± 0.71). The overall correct response rate for the knowledge questions was 57.7%. The majority of participants (95.5%) agreed that physicians should routinely provide information about egg freezing to women of childbearing age during their regular healthcare visits.

CONCLUSIONS

The research results revealed that female students in Tehran universities have a positive attitude towards medical and social egg freezing, but lack sufficient knowledge about the ideal timing of childbearing. Health professionals could provide detailed information about fertility preservation and age-related infertility as part of routine healthcare visits or reproductive health planning. Additionally, expanding supportive policies and incentives for childbearing established by the government to cover the costs of fertility preservation would be beneficial.

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.

Antioxidant procyanidin B2 protects oocytes against cryoinjuries via mitochondria regulated cortical tension

BACKGROUND

Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation. Antioxidants were always used to antagonist the oxidative stress caused by vitrification. However, the comprehensive mechanism underlying the protective role of antioxidants has not been studied. Procyanidin B2 (PCB2) is a potent natural antioxidant and its functions in response to vitrification are still unknown. In this study, the effects of PCB2 on vitrified-thawed oocytes and subsequent embryo development were explored, and the mechanisms underlying the protective role of PCB2 were systematically elucidated.

RESULTS

Vitrification induced a marked decline in oocyte quality, while PCB2 could improve oocyte viability and further development after parthenogenetic activation. A subsequent study indicated that PCB2 effectively attenuated vitrification-induced oxidative stress, rescued mitochondrial dysfunction, and improved cell viability. Moreover, PCB2 also acts as a cortical tension regulator apart from strong antioxidant properties. Increased cortical tension caused by PCB2 would maintain normal spindle morphology and promote migration, ensure correct meiosis progression and finally reduce the aneuploidy rate in vitrified oocytes. Further study reveals that ATP biosynthesis plays a crucial role in cortical tension regulation, and PCB2 effectively increased the cortical tension through the electron transfer chain pathway. Additionally, PCB2 would elevate the cortical tension in embryo cells at morula and blastocyst stages and further improve blastocyst quality. What's more, targeted metabolomics shows that PCB2 has a beneficial effect on blastocyst formation by mediating saccharides and amino acids metabolism.

CONCLUSIONS

Antioxidant PCB2 exhibits multi-protective roles in response to vitrification stimuli through mitochondria-mediated cortical tension regulation.

Age-Specific Distribution of Serum Anti-Mullerian Hormone and Antral Follicle Count in Indian Infertile Women

BACKGROUND

Ovarian reserve declines with age. However, there are considerable ethnic differences in the decline of ovarian reserve between individuals.

AIM

This study aimed to make age-specific percentile charts of anti-Mullerian hormone (AMH) and antral follicle count (AFC) in Indian infertile women and to find the proportion of young women with low ovarian reserve.

SETTING AND DESIGN

This was a retrospective data analysis of AMH and AFC of 5525 infertile women from August 2015 to December 2018.

MATERIALS AND METHODS

Infertile women aged 20- 44 years, with body mass index 18-32 kg/m2 and having both ovaries were included in the study. Women with pituitary/adrenal disorders, malignancy, total AFC >40, tuberculosis, endometriosis, autoimmune disorders, smoking, chemotherapy, radiotherapy and recent ovarian surgery were excluded from the study.

STATISTICAL ANALYSIS

Comparison between groups was done by Chi-square test.

RESULTS

About 14.5% of women <35 years and 50.5% of women >35 years had low AMH values (<1.1 ng/ml). In addition, 5.6% of women <35 years and 23.6% of women >35 years had a low AFC of ≤5. In this study, 55.7% of women who had low AMH and 50.7% who had low AFC were <35 years of age. The median AMH values were 4.23 ng/mL in 20-25 years' age group, 3.48 ng/mL in women aged 26-30 years, 2.43 ng/mL in women aged 31-35 years, 1.28 ng/mL in women aged 36-40 years and0.52 ng/mL in 40-44 years' age group. The median AFCs were 20, 18, 14, 10 and 6 for each of the age groups, respectively.

CONCLUSION

This study suggests that approximately more than half of the infertile women who were tested to have low ovarian reserve were <35 years of age.

Current perspectives on social oocyte freezing

Demand for oocyte freezing in absence of a medical indication is growing as women delay childbirth and seek to extend the window of opportunity for parenthood. The optimum age for oocyte freezing is below 35 years, whereas currently the mean age of women undergoing oocyte freezing in the UK is 38 years. Nearly half of women undergoing oocyte freezing are not in a relationship. The treatment is not publicly funded and the average price for a complete oocyte freezing and thawing cycle, including annual storage fees, could reach over £7000. The live birth rate per oocyte thaw cycle is 18% and is influenced by age at the time of oocyte freezing. Women considering social oocyte freezing should be thoroughly counselled about the efficacy, limitations, cost implications and alternatives to oocyte freezing and provided with the appropriate support to enable a truly informed reproductive choice.

Highly successful production of viable mice derived from vitrified germinal vesicle oocytes

The vitrification of immature germinal vesicle (GV) oocytes is an important way to preserve genetic resources and female fertility. However, it is well known that cryopreserved GV oocytes have very poor developmental ability and that further improvement in this technique is needed. We previously reported the successful vitrification of matured mouse oocytes with enclosed cumulus cells using the calcium-free vitrification solution supplemented with ethylene glycol (EG) by the minimal volume cooling (MVC) method. In this study, we investigated whether our method is applicable to the vitrification of mouse oocytes at the GV stage (GV oocytes). Following maturation and fertilization in vitro, vitrified GV oocytes showed high survival (94.3 ± 2.0%) and maturation (94.3 ± 2.1%) rates. Although the fertilization and blastocyst rates of vitrified oocytes (fertilization: 46.6 ± 4.9% and blastocyst: 46.6 ± 3.0%) were significantly lower than those of fresh oocytes (fertilization: 73.0 ± 7.1% and blastocyst: 71.6 ± 8.0%) (P < 0.01), there were no differences in the ability to develop to term between fresh oocytes (50.0 ± 8.4%) and vitrified oocytes (37.5 ± 4.6%) (P > 0.05). In conclusion, we here show, for the first time, the efficient production of live mice derived from vitrified GV oocytes.

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.

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.

Safety of Ovaleap® (Follitropin Alfa) in Infertile Women Undergoing Superovulation for Assisted Reproductive Technologies: A Multinational Comparative, Prospective Cohort Study

BACKGROUND

Ovaleap^® (follitropin alfa), a recombinant human follicle stimulating hormone, is a biosimilar medicinal product to Gonal-f^® and is used for ovarian stimulation. The main objective of this study was to assess the safety and effectiveness of Ovaleap^® compared to Gonal-f^® in one treatment cycle in routine clinical practice.

METHODS

Safety of Ovaleap^® Follitropin alfa in Infertile women undergoing superovulation for Assisted reproductive technologies (SOFIA) was a prospective cohort study conducted in six European countries. Eligible patients were infertile women undergoing superovulation for assisted reproductive technology, who were administered Ovaleap^® or Gonal-f^® for ovarian stimulation and were naïve to follicle stimulating hormone treatment. The recruitment ratio was 1:1. The primary endpoint was incidence proportion of ovarian hyperstimulation syndrome (OHSS) and the secondary endpoint was OHSS severity (Grades I, II, III). The effect of risk factors or potential confounders on the odds ratio for OHSS incidence as well as treatment effect on OHSS incidence was explored using univariate logistic regression. Pregnancy and live birth rates were also assessed.

RESULTS

A total of 408 women who were administered Ovaleap^® and 409 women who were administered Gonal-f^® were eligible for analysis. The incidence proportion of OHSS was 5.1% (95% CI: 3.4, 7.7) in the Ovaleap^® cohort and 3.2% (95% CI: 1.9, 5.4) in the Gonal-f^® cohort. This difference in OHSS incidence proportion between the two cohorts was not statistically significant neither before (p = 0.159) nor after univariate adjustment for each potential confounder (p > 0.05). The incidence proportion of OHSS severity grades was similar in the two treatment groups (3.4% versus 2.0% for Grade I, 1.2% versus 1.0% for Grade II, and 0.5% versus 0.2% for Grade III, in the Ovaleap^® and Gonal-f^® cohorts, respectively), without a significant statistical difference (p = 0.865, for each grade). Among patients who had embryo transfer, clinical pregnancy rates were 33% and 31% and live birth rates were 27% and 26%, in the two cohorts, respectively.

CONCLUSIONS

Findings from the SOFIA study indicate that the incidence proportions of OHSS and OHSS severity, as well as pregnancy and live birth rates, are similar between Ovaleap^® and Gonal-f^® treatments and corroborate the safety and effectiveness of Ovaleap^® as a biosimilar to Gonal-f^®.

The Conundrum of Poor Ovarian Response: From Diagnosis to Treatment

Despite recent striking advances in assisted reproductive technology (ART), poor ovarian response (POR) diagnosis and treatment is still considered challenging. Poor responders constitute a heterogeneous cohort with the common denominator of under-responding to controlled ovarian stimulation. Inevitably, respective success rates are significantly compromised. As POR pathophysiology entails the elusive factor of compromised ovarian function, both diagnosis and management fuel an ongoing heated debate depicted in the literature. From the criteria employed for diagnosis to the plethora of strategies and adjuvant therapies proposed, the conundrum of POR still puzzles the practitioner. What is more, novel treatment approaches from stem cell therapy and platelet-rich plasma intra-ovarian infusion to mitochondrial replacement therapy have emerged, albeit not claiming clinical routine status yet. The complex and time sensitive nature of this subgroup of infertile patients indicates the demand for a consensus on a horizontally accepted definition, diagnosis and subsequent effective treating strategy. This critical review analyzes the standing criteria employed in order to diagnose and aptly categorize POR patients, while it proceeds to critically evaluate current and novel strategies regarding their management. Discrepancies in diagnosis and respective implications are discussed, while the existing diversity in management options highlights the need for individualized management.

The Effect of Human Chorionic Gonadotropin on the In vitro Development of Immature to Mature Human Oocytes: A Randomized Controlled Study

Context

In controlled ovarian hyperstimulation cycles, 15% of oocytes have been proven to be immature. Key factors include failure in signal transmission from the cumulus cell to the oocyte, insufficient level of luteinizing hormone, and internal conditions of the oocyte itself.

Aims

The aim of the present study was to investigate the effect of human chorionic gonadotropin (hCG) on the in vitro maturity of partially cumulus-denuded immature oocytes collected after controlled ovarian stimulation for in vitro fertilization (IVF).

Settings and Design

This was a prospective, randomized controlled design at the department of obstetrics and gynaecology, university hospital.

Subjects and Methods

Infertile women underwent gonadotropin-releasing hormone antagonist stimulated protocol for IVF with final maturation triggered by hCG, partially cumulus-denuded immature human oocytes were allocated to two groups: the first was treated with fertilization medium and the second was treated with fertilization medium and hCG. They were cultured for 24 h. Outcomes measured were the oocyte maturation rates to metaphase II (MII) and glucose-6-phosphate dehydrogenase (G6PD) activity of in vitro maturation (IVM) mature oocytes which represent the oocyte quality.

Statistical Analysis Used

The Mann-Whitney U-test and One-way ANOVA were used to compare continuous variables, and Chi-square was used for categorical data.

Results

In all, 250 immature stimulated oocytes were allocated (125 per group). The maturation rate was higher in the hCG supplement group (48% vs. 39.2%) without significance. The positive brilliant cresyl blue results among the MII oocytes developed from the metaphase I (MI) were significantly higher in the hCG group (P = 0.001).

Conclusions

Rescue IVM in fertilization culture medium plus hCG was slightly better than that in the only fertilization culture. MII oocytes developed from MI in hCG supplemented medium had a higher quality based on the measured G6PD activity.