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.

Racial Disparities in Fertility Care: A Narrative Review of Challenges in the Utilization of Fertility Preservation and ART in Minority Populations

Significant ethnic and racial disparities exist in the utilization and outcomes of assisted reproductive technology (ART) in the United States. The popularity of fertility preservation (FP) procedures, a specific application of ART for those desiring to delay childbearing, has increased; however, many minority populations have seen a less rapid uptake of these services. Minority patients pursuing ART are more likely to have poorer in vitro fertilization (IVF) and pregnancy outcomes. These outcomes are used to predict success after FP and may lessen the appeal of such procedures in these populations. Suboptimal outcomes are further compounded by challenges with receiving referrals to, accessing, and paying for FP services. Resolving these disparities in minority populations will require culturally appropriate education surrounding the benefits of ART and FP, the demonstration of favorable outcomes in ART and FP through continued research engaging minority participants, and continued advocacy for expanded access to care for patients.

A 10-year follow-up of reproductive outcomes in women attempting motherhood after elective oocyte cryopreservation

STUDY QUESTION

Which reproductive treatment outcomes are observed in women who underwent elective oocyte cryopreservation (EOC) and who returned to the clinic with a desire for a child?

SUMMARY ANSWER

Whether to warm oocytes or to first use fresh own oocytes for ART depends on age upon returning, but both strategies result in favorable reproductive outcomes.

WHAT IS KNOWN ALREADY

Most affluent countries have observed a trend toward postponement of childbearing, and EOC is increasingly used based on the assumption that oocytes cryopreserved at a younger age may extend a woman's reproductive lifespan and mitigate her age-related fertility decline. Although most follow-up studies after EOC have focused on women who requested oocyte warming, a substantial proportion of women who do not conceive naturally will embark on fertility treatment without using their cryopreserved oocytes. Reports on reproductive outcomes in past EOC users are scarce, and the lack of reproductive treatment algorithms in this group of women hampers counseling toward the most efficient clinical strategy.

STUDY DESIGN, SIZE, DURATION

This retrospective observational single-center study encompasses 843 women who had elective oocyte vitrification between 2009 and 2019 at our fertility clinic. Women who underwent fertility preservation for medical or oncological reasons were excluded. This study describes the outcomes of the diverse reproductive treatment strategies performed until May 2022 in women returning to our clinic to attempt motherhood.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Using descriptive statistics, patient characteristics and data of ovarian stimulation (OS) of EOC cycles were analyzed, as well as data related to OS and laboratory data of ART in women who pursued fertility treatment with and/or without using their cryopreserved oocytes. The primary outcome was live birth rate (LBR) per patient after oocyte warming and after ART using fresh oocytes. Secondary outcomes were return rate, utilization rate of the cryopreserved oocytes, laboratory outcomes upon return, and LBR per embryo transfer. A multivariable regression model was developed to identify factors associated with the decision to thaw oocytes as the primary strategy and factors associated with ongoing pregnancy upon return to the clinic.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1353 EOC cycles (mean ± SD, 1.6 ± 0.9 per patient) were performed. At the time of EOC, the mean age was 36.5 ± 2.8 years, mean anti-Müllerian hormone (AMH) was 2.3 ± 2.0 ng/ml, and 174 (20.6%) women had a partner. On average, 13.9 ± 9.2 mature oocytes were cryopreserved. Two hundred thirty-one (27.4%) women returned to the clinic, an average of 39.9 ± 23.4 months after EOC. Upon returning, their mean age was 40.4 ± 3.1 years, mean AMH was 1.5 ± 1.5 ng/ml, and 158/231 (68.3%) patients had a partner. As a primary approach, 110/231 (47.6%) past EOC users embarked on oocyte warming, 50/231 (21.6%) had intrauterine insemination, and 71/231 (30.7%) had ART using fresh own oocytes. Cumulative LBR (CLBR) was 45.9% (106/231) notwithstanding a miscarriage rate (MR) of 30.7% (51/166) in the entire cohort. In total, 141 women performed oocyte warming at some stage in their treatment trajectory. A subset of 90/231 (39.0%) patients exclusively had oocyte warming (41.6 ± 3.0 years, with 10.0 ± 5.2 oocytes warmed per patient). 52/231 (22.5%) patients exclusively had ART using fresh own oocytes (mean age of 39.0 ± 2.8 years, with 9.9 ± 7.4 mature oocytes retrieved per patient). CLBR was 37/90 (41.1%) in the oocyte warming-only group and 25/52 (48.1%) in the OS-only group. MR/transfer was 25.0% and 29.3% in the oocyte warming-only group and the OS-only group, respectively.

LIMITATIONS, REASONS FOR CAUTION

Both sample size and the retrospective design are limitations of this study. The decision to embark on a specific reproductive treatment strategy was based on patient preference, after counseling on their treatment options. This precludes direct comparison of the efficiency of reproductive treatment options in past EOC users in this study.

WIDER IMPLICATIONS OF THE FINDINGS

Reporting on clinical outcomes of women who underwent EOC and returned to the clinic to embark on divergent reproductive treatment strategies is mandatory to establish guidelines for best clinical practice in this growing patient population.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

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.

Single women's access to egg freezing in mainland China: an ethicolegal analysis

In the name of safeguarding public interests and ethical principles, China's National Health Commission bans unmarried women from using assisted reproductive technology (ART), including egg freezing. Supported by local governments, the ban has restricted single women's reproductive rights nationwide. Although some courts bypassed the ban to allow widowed single women to use ART, they have not adopted a position in favour of single women's reproductive autonomy, but quite the contrary. Faced with calls to relax the ban and allow single women to freeze eggs electively, the National Health Commission refused to amend their policy, partly to protect women's well-being paternalistically and partly to implement the central government's policies to boost the birthrate and maintain traditional family structures. While the government's concerns about elective egg freezing are not entirely unfounded, they have failed to demonstrate that banning single women's egg freezing is a suitable, necessary and proportionate means to safeguard societal interests and ethical principles. The authority's assumptions that women cannot make rational decisions for their health even with adequate informed consent procedures, that banning egg freezing by single women promotes a culture of having children 'at a proper age', and that egg freezing by single women offends China's public moralities have not been substantiated.

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.

Review of human oocyte cryopreservation in ART programs: Current challenges and opportunities

Oocyte cryopreservation has notably increased in recent times, to become an essential part of clinical infertility treatment. Since the 1980s, many improvements in oocyte cryopreservation (OC) have been adopted, including the great advance with the application of vitrification. The commonly used vitrification protocol applies different cryoprotectants (Ethylene glycol and/or DMSO and/or PROH and sucrose and/or Trehalose) and two different steps: firstly, exposure in equilibration solution for 5-15 min, followed by a vitrification solution for 60-90 s at room temperature. The warming method includes a first step for 1 min at 37 °C and 3 subsequent steps at room temperature to remove the cryoprotectant for a total of 9-12 min. In addition, biosafety is a critical aspect to mention, and it is related to devices used during the vitrification, mainly in terms of whether the biological vitrified material comes in direct contact with liquid nitrogen (open vitrification) or not (closed vitrification), where LN2 may contain potentially contaminating viruses or pathogens. Furthermore, during early development major waves of epigenetic reprogramming take place. Recent literature suggests that epigenetic and transcriptomic profiles are sensitive to the stress induced by vitrification, including osmotic shock, temperature, rapid changes of pH and toxicity of cryoprotectants. It is, therefore, important to better understand the potential perturbations of epigenetic modifications that may be associated with the globally used vitrification methods. Therefore, we here discuss the benefits and efficiency of human oocyte vitrification; we also review the evidence surrounding oocyte cryopreservation-related epigenetic modifications and potential epigenetic dysregulations, together with long-term consequences for offspring health.

Embryological Characteristics and Preimplantation Genetic Testing for Aneuploidy of Embryos Derived from Cryopreserved Oocytes of Women of Different Reproductive Ages

Oocyte vitrification is widely used for female fertility preservation. However, the efficacy of this procedure may depend on the women's age. The aim of the study was to compare the morphology, viability of cryopreserved oocytes, and their fertilization outcomes (fertilization, blastulation rate, level of embryo chromosomal aneuploidy-preimplantation genetic testing for aneuploidy [PGT-A]) in women of different reproductive ages. The studied oocytes were divided into groups depending on the age of patients: up to 30 years (group 1), 30-35 years (group 2), 36-40 years (group 3), and older than 40 years (group 4). It has been shown that in women of older reproductive age, the number of oocytes with polymorphism of endo- and extracytoplasmic structures was higher compared with younger patients. This could reflect on their cryosurvival rate, which was the highest in group 1 (98.1%) and the lowest was in group 4 (47.4%). With increasing age, the fertilization rate of cryopreserved oocytes and subsequent blastulation was decreased. However, the number of embryos with an aneuploid chromosome set number was increased. The chromosome set number euploidy rate of the embryos obtained from cryopreserved oocytes of advanced age women (group 4) did not differ from the fresh group with the same age (31.2% vs. 24.4%, p > 0.05), but the number of euploid embryos per patient was less than one (0.8 ± 0.1). Therefore, the decision to cryopreserve the oocytes of a patient of older reproductive age should be made individually for each situation, taking into account the prospects of obtaining full-fledged embryos and the chances of pregnancy.

Outcomes of Social Egg Freezing: A Cohort Study and a Comprehensive Literature Review

The purpose of this study is to evaluate the live birth outcome following oocyte thaw in women who underwent social egg freezing at Guy's Hospital, alongside a detailed published literature review to compare published results with the current study. A retrospective cohort study was conducted between January 2016 and March 2022 for all women who underwent egg freezing during this period. Overall, 167 women had 184 social egg freezing cycles. The mean age at freeze was 37.1 years and an average of 9.5 eggs were frozen per retrieval. In total, 16% of the women returned to use their frozen eggs. The mean egg thaw survival rate post egg thaw was 74%. The mean egg fertilisation rate was 67%. The pregnancy rate achieved per embryo transfer was 48% and the live birth rate per embryo transfer was 35%. We also noted that irrespective of age at freezing, a significantly high live birth rate was achieved when the number of eggs frozen per patient was 15 or more. Despite the rapid increase in social egg freezing cycles, the utilisation rate remains low. Pregnancy and live birth rate post thaw are encouraging if eggs are frozen at a younger age and if 15 eggs or more were frozen per patient.

Elective egg freezers' disposition decisions: a qualitative study

OBJECTIVE

To explore the factors that influence elective egg freezers' disposition decisions toward their surplus-frozen oocytes.

DESIGN

Qualitative.

SETTING

Not applicable.

PATIENT(S)

Thirty-one participants: 7 past; 6 current; and 18 future oocyte disposition decision-makers.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Qualitative thematic analysis of interview transcripts.

RESULTS

Six inter-related themes were identified related to the decision-making process which are as follows: decisions are dynamic; triggers for the final decision; achieving motherhood; conceptualization of oocytes; the impacts of egg donation on others; and external factors affecting the final disposition outcome. All women reported a type of trigger event for making a final decision (e.g., completing their family). Women who achieved motherhood were more open to donating their oocytes to others but were concerned about the implications for their child and felt responsibility for potential donor children. Women who did not achieve motherhood were unlikely to donate to others due to the grief of not becoming a mother, often feeling alone, misunderstood, and unsupported. Reclaiming oocytes (e.g., taking them home) and closure ceremonies helped some women process their grief. Donating to research was viewed as an altruistic option as oocytes would not be wasted and did not have the "complication" of a genetically-linked child. There was a general lack of knowledge around disposition options at all stages of the process.

CONCLUSION(S)

Oocyte disposition decisions are dynamic and complex for women, exacerbated by a general lack of understanding of these options. The final decision is framed by: whether women achieved motherhood, dealing with grief if they did not achieve motherhood, and considering the complexities of donating to others. Additional decision support through counseling, decision aids, and early consideration of disposition when eggs are initially stored may help women make informed decisions.

Randomized control trial of a decision aid for women considering elective egg freezing: The Eggsurance study protocol

BACKGROUND

Uptake of elective egg freezing has increased globally. The decision to freeze eggs is complex, and detailed, unbiased information is needed. To address this, we developed an online Decision Aid for women considering elective egg freezing. Decision Aids are the standard of care to support complex health decisions.

OBJECTIVES

This study will measure the impact of the Decision Aid on decision-making (e.g. decisional conflict, engagement in decision-making, distress, and decision delay) and decision quality (e.g. knowledge, level of informed choice, and regret).

METHODS AND ANALYSIS

A single-blinded two-arm parallel-group randomized controlled trial. Women considering elective egg freezing will be recruited using social media, newsletters, and fertility clinics. Data will be collected at baseline (recruitment), 6-month, and 12-month post-randomization. The primary hypothesis is that the intervention (Decision Aid plus Victorian Assisted Reproductive Technology Authority website) will reduce decisional conflict (measured using the Decisional Conflict Scale) at 12 months more than control (Victorian Assisted Reproductive Technology Authority website only). Secondary outcomes include engagement in decision-making (Perceived Involvement in Care Scale), distress (Depression, Anxiety, and Stress Scale), decision delay, knowledge, informed choice (Multi-dimensional Measure of Informed Choice), and decisional regret (Decisional Regret Scale).

ETHICS

The study was approved by the University of Melbourne Human Research Ethics Committee (Ethics ID: 2056457). Informed consent will be obtained from all participants prior to enrolment.

DISCUSSION

This is the first international randomized controlled trial that aims to investigate the effect of an elective egg freezing Decision Aid on decision-related outcomes (e.g. decisional conflict, informed choice, and regret). It is anticipated that participants who receive the Decision Aid will have better decision and health outcomes.

REGISTRATION DETAILS

ACTRN12620001032943: Comparing different information resources on the process and quality of decision-making in women considering elective egg freezing.

Clinical outcome of planned oocyte cryopreservation at advanced age

PURPOSE

To report outcome of planned oocyte cryopreservation (POC) in the first 8 years of this treatment in our center.

METHODS

A retrospective study in a university-affiliated medical center.

RESULTS

A total of 446 women underwent POC during 2011-2018. Fifty-seven (13%) women presented to use these oocytes during the study period (until June 2021). POC was performed at a mean age of 37.9 ± 2.0 (range 33-41). Age at thawing was 43.3 ± 2.1 (range 38-49). A total of 34 (60%) women transferred their oocytes for thawing at other units. Oocyte survival after thawing was significantly higher at our center than following shipping to ancillary sites (78 vs. 63%, p = 0.047). Forty-nine women completed their treatment, either depleting their cryopreserved oocytes without conceiving (36) or attaining a live birth (13)-27% live birth rate per woman. Only one of eleven women who cryopreserved oocytes aged 40 and older had a live birth using thawed oocytes.

CONCLUSION

Women should be advised to complete planned oocyte cryopreservation before age 40, given low success rates in women who underwent cryopreservation at advanced reproductive age. In this study, oocyte shipping was associated with lower survival rate. These findings may be relevant for women considering POC and utilization of cryopreserved oocytes.

Reproductive outcomes from ten years of elective oocyte cryopreservation

RESEARCH QUESTION

To assess the relationship between the number of oocytes retrieved during elective oocyte cryopreservation (EOC) cycles with various clinical, biochemical, and radiological markers, including age, body mass index (BMI), baseline anti-Müllerian hormone (AMH), antral follicle count (AFC), Oestradiol level (E2) and total number of follicles ≥ 12 mm on the day of trigger. To also report the reproductive outcomes from women who underwent EOC.

METHODS

A retrospective cohort of 373 women embarking on EOC and autologous oocyte thaw cycles between 2008 and 2018 from a single London clinic in the United Kingdom.

RESULTS

483 stimulation cycles were undertaken amongst 373 women. The median (range) age at cryopreservation was 38 (26-47) years old. The median numbers of oocytes retrieved per cycle was 8 (0-37) and the median total oocytes cryopreserved per woman was 8 (0-45). BMI, E2 level and number of follicles ≥ 12 mm at trigger were all significant predictors of oocyte yield. Multivariate analysis confirmed there was no significant relationship between AFC or AMH, whilst on univariate analysis statistical significance was proven. Thirty six women returned to use their cryopreserved oocytes, of which there were 41 autologous oocyte thaw cycles undertaken. There were 12 successful livebirths achieved by 11 women. The overall livebirth rate was 26.8% per cycle. No livebirths were achieved in women who underwent EOC ≥ 40 years old, and 82% of all livebirths were achieved in women who had done so between 36 and 39 years old.

CONCLUSION

Clinical, biochemical and radiological markers can predict oocyte yield in EOC cycles. Reproductive outcomes are more favourable when cryopreservation is performed before the age of 36, with lower success rates of livebirth observed in women aged 40 years and above.

Usage and cost-effectiveness of elective oocyte freezing: a retrospective observational study

BACKGROUND

The previous model-based cost-effectiveness analyses regarding elective oocyte cryopreservation remained debatable, while the usage rate may influence the cost per live birth. The aim of this study is to disclose the usage and cost-effectiveness of the planned cryopreserved oocytes after oocyte thawing in real-world situations.

METHODS

This was a retrospective single-center observational study. Women who electively cryopreserved oocytes and returned to thaw the oocytes were categorized as thawed group. The oocytes were fertilized at our center and the sperm samples for each individual was retrieved from their respective husbands. Clinical outcomes were traced and the cumulative live birth rate per thawed case was calculated. The costs from oocyte freezing cycles to oocyte thawing, and embryo transfer cycles were accordingly estimated. The cumulative cost per live birth was defined by the cumulative cost divided by the live births per thawed case.

RESULTS

We recruited 645 women with 840 oocyte retrieval cycles for elective oocyte freezing from November 2002 to December 2020. The overall usage rate was 8.4% (54/645). After the storage duration exceeded ten years, the probabilities of thawing oocytes were 10.6%, 26.6%, and 12.7% from women who cryopreserved their oocytes at the age ≤ 35 years, 36-39 years, and ≥ 40 years, respectively (P = 0.304). Among women who thawed their oocytes, 31.5% (17/54) of women achieved at least one live birth. For the age groups of ≤ 35 years, 36-39 years, and ≥ 40 years, the cumulative live birth rates per thawed case were 63.6%, 42.3%, and 17.6%, respectively (P = 0.045), and the cumulative costs for one live birth were $11,704, $17,189, and $35,642, respectively (P < 0.001).

CONCLUSIONS

The overall usage rate was 8.4% in our cohort. The cumulative live birth rate was greatest in the youngest group and the cumulative cost per live birth was highest in the oldest group, which was threefold greater than that in the group aged ≤ 35 years. The findings added to the limited evidence of the usage rate in real-world situations, which could hopefully aid future analysis and decision-making in public health policy and for women willing to preserve fertility.

TRIAL REGISTRATION

None.

Planned oocyte cryopreservation for fertility preservation

Background: Oocyte cryopreservation opens up opportunities for women to preserve fertility when it is necessary to postpone pregnancy. After the advent of vitrification, the results of oocyte cryopreservation were significantly improved compared to conventional slow-freezing. Through these improvements, oocyte cryopreservation was introduced to overcome a decline in fecundity due to an increase in age, and this modality is defined as planned oocyte cryopreservation.Current Concepts: Oocytes cryopreserved through vitrification appear to result in similar clinical pregnancy rates and live birth rates compared to fresh oocytes, though the evidence is still limited. It has been reported that the live birth rate increases when the planned oocyte cryopreservation is performed at a younger age. Obstetrical and neonatal outcomes appear similar between vitrified and fresh oocytes.Discussion and Conclusion: Preliminary data supports planned oocyte cryopreservation as a feasible modality resulting in fertility preservation and subsequent live births. The fact that performing the procedure at a younger age can increase the oocyte yield, oocyte efficacy, and live birth rate can be discussed along with patient consultation. However, as there is still a lack of data on the standardized live birth rate, the number of oocytes to be collected, and the long-term effect on the children; more well-designed studies are needed to improve counseling and decision-making in patients seeking this treatment.

Fifteen years of autologous oocyte thaw outcomes from a large university-based fertility center

OBJECTIVE

To review the outcomes of patients who underwent autologous oocyte thaw after planned oocyte cryopreservation.

DESIGN

Retrospective cohort study.

SETTING

Large urban university-affiliated fertility center.

PATIENT(S)

All patients who underwent ≥1 autologous oocyte thaw before December 31, 2020.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was the final live birth rate (FLBR) per patient, and only patients who had a live birth (LB) or consumed all remaining inventory (cryopreserved oocytes and resultant euploid/untested/no result embryos) were included. The secondary outcomes were laboratory outcomes and LB rates per transfer.

RESULT(S)

A total of 543 patients underwent 800 oocyte cryopreservations, 605 thaws, and 436 transfers. The median age at the first cryopreservation was 38.3 years. The median time between the first cryopreservation and thaw was 4.2 years. The median numbers of oocytes and metaphase II oocytes (M2s) thawed per patient were 14 and 12, respectively. Overall survival of all thawed oocytes was 79%. Of all patients, 61% underwent ≥1 transfer. Among euploid (n = 262) and nonbiopsied (n = 158) transfers, the LB rates per transfer were 55% and 31%, respectively. The FLBR per patient was 39%. Age at cryopreservation and the number of M2s thawed were predictive of LB; the FLBR per patient was >50% for patients aged <38 years at cryopreservation or who thawed ≥20 M2s. A total of 173 patients (32%) have remaining inventory.

CONCLUSION(S)

Autologous oocyte thaw resulted in a 39% FLBR per patient, which is comparable with age-matched in vitro fertilization outcomes. Studies with larger cohorts are necessary.

Financing future fertility: Women's views on funding egg freezing

Like other assisted reproductive technology (ART) procedures, the cost of egg freezing (EF) is significant, presenting a potential barrier to access. Given recent technological advancements and rising demand for EF, it is timely to reassess how EF is funded. An online cross-sectional survey was conducted in Victoria, Australia and was completed by 656 female individuals. Participants were asked their views on funding for both medical and non-medical EF. The median age of participants was 28 years (interquartile range 23-37 years) and most participants were employed (44% full-time, 28% part-time, 33% students). There was very high support for public funding for medical EF (n = 574, 87%), with 302 (46%) participants indicating support for the complete funding of medical EF through the public system. Views about funding for non-medical EF were more divided; 43 (6%) participants supported full public funding, 235 (36%) supported partial public funding, 150 (23%) supported coverage through private health insurance, and 204 (31%) indicated that non-medical EF should be self-funded. If faced with the decision of what to do with surplus eggs, a high proportion of participants indicated that they would consider donation (71% to research, 59% to a known recipient, 52% to a donor programme), indicating that eggs surplus to requirements could be a potential source of donor eggs. This study provides insights that could inform policy review, and suggests revisiting whether the medical/non-medical distinction is a fair criterion to allocate funding to ART.

Oocyte cryopreservation review: outcomes of medical oocyte cryopreservation and planned oocyte cryopreservation

BACKGROUND

The utilization of oocyte cryopreservation (OC) has become popularized with increasing numbers of reproductive-aged patients desiring to maintain fertility for future family building. OC was initially used for fertility preservation in postmenarchal patients prior to gonadotoxic therapies; however, it is now available to patients to circumvent age-related infertility and other diagnoses associated with early loss of ovarian reserve. The primary aim of this paper is to provide a narrative review of the most recent and robust data on the utilization and outcomes of OC in both patient populations. OC results in similar oocyte yield in patients facing gonadotoxic therapies and patients undergoing planned OC. Available data are insufficient to predict the live birth rates or the number of oocytes needed to result in live birth. However, oocyte yield and live birth rates are best among patients < 37.5 years old or with anti-mullerian hormone levels > 1.995 ng/dL, at the time of oocyte retrieval. There is a high 'no use' rate (58.9%) in patients using planned OC with 62.5% returning to use frozen oocytes with a spouse. The utilization rate in medical OC patients is < 10%. There is currently no data on the effects of BMI, smoking, or ethnicity on planned OC outcomes.

CONCLUSION

It is too early to draw any final conclusions on outcomes of OC in medical OC and planned OC; however, preliminary data supports that utilization of OC in both groups result in preservation of fertility and subsequent live births in patients who return to use their cryopreserved eggs. Higher oocyte yield, with fewer ovarian stimulation cycles, and higher live birth rates are seen in patients who seek OC at younger ages, reinforcing the importance of age on fertility preservation. More studies are needed in medical OC and planned OC to help guide counseling and decision-making in patients seeking these services.

Why are they not coming back? A single-center follow-up study on oncological women oocyte's storing for fertility preservation

INTRODUCTION

Oocyte cryopreservation is a valid option for female cancer patients to preserve fertility. The number of patients undergoing fertility preservation (FP) cycles has increased over the past years. Nevertheless, the rates of patients returning to use their cryopreserved material have shown to be considerably low, ranging from 5-8%, but significant data regarding the reasons of such low return rates are scarce.

METHODS

This study is a single-center follow-up retrospective study evaluating the return rate of oncological women who underwent FP at a tertiary care Fertility Center and assessing the reasons influencing the patients who did not return. Data about patients who returned to attempt pregnancy were retrieved from internal registries. Non-returned patients were assessed with a standardized phone survey investigating health condition, marital status and family projects, spontaneous conceptions, and the reasons why they had not returned to use their gametes. A univariate analysis between returned and non-returned patients was performed.

RESULTS

Of the 397 patients who received counseling about FP, 171 (43.1%) underwent oocyte cryopreservation between 2001 and 2017. Nine (5%) died, and 17 (10%) were lost at follow-up. A total of 20 patients (11.7%) returned and 125 did not. In the non-returned group, 37 (29.6%) did not have a partner, 10 (8%) had a previous spontaneous conception, and 15 (12%) had recurrent malignancy at the time of follow-up. In the univariate analysis, younger age at freezing (31.8±6.2 vs. 35.2±4.7; p 0.018), lack of a partner (p 0.002), type of cancer (other than breast cancer; p 0.024) were the significant factors in the non-returned group. As for the personal reason for not coming back, patients mainly answered as follows: lack of a partner (29, 23.2%), the desire for spontaneous motherhood (24, 19.2%), previous spontaneous pregnancies after FP procedures (16, 12.8%), and still ongoing hormonal therapy for breast cancer (13, 10.4%). All patients confirmed their will to keep the storage of their oocytes.

DISCUSSION

The impact of a cancer diagnosis on a woman's maternal desire, sentimental status and life priorities should be studied more thoroughly. Studies investigating hormonal therapy suppression in breast cancer patients seeking pregnancy should be encouraged.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov, identifier NCT05223764.

Clinical outcomes and utilization from over a decade of planned oocyte cryopreservation

RESEARCH QUESTION

What is the clinical experience of patients who have undergone planned oocyte cryopreservation and oocyte thawing and warming?

DESIGN

Retrospective observational cohort study. All women who completed planned oocyte cryopreservation at a single large university-affiliated fertility centre between June 2006 and October 2020 were identified, including the subset who returned to use their oocytes. Patients who underwent oocyte cryopreservation for medical reasons were excluded. Baseline demographics, oocyte cryopreservation and thawing-warming cycle parameters, and clinical outcomes, were extracted from the electronic medical record. The primary outcome was cumulative live birth rate (LBR), and secondary outcomes were cumulative clinical pregnancy rate (CPR), and CPR and LBR per transfer. Results were stratified by age at time of cryopreservation (<38 and ≥38 years).

RESULTS

Of 921 patients who underwent planned oocyte cryopreservation, 68 (7.4%) returned to use their oocytes. Forty-six patients (67.6%) completed at least one embryo transfer. The CPR per transfer was 47.5% and LBR was 39.3%. The cumulative LBR per patient who initiated thawing-warming was 32.4%. Cycle outcomes were not significantly different in patients aged younger than 38 years and those aged 38 years or over. No patient aged 40 years or older (n = 6) was successful with their cryopreserved oocytes. Ten patients (14.7%) who were unsuccessful with their cryopreserved oocytes achieved a live birth using donor oocytes, with most (7/10) of these patients aged 38 years and older.

CONCLUSION

Only a small percentage of patients returned to use their oocytes, and 32% of those were able to achieve a live birth.

'Why have women not returned to use their frozen oocytes?': a 5-year follow-up of women after planned oocyte cryopreservation

RESEARCH QUESTION

What are the reproductive choices and retrospective reflections of women at least 4 years after planned oocyte cryopreservation (POC)?

DESIGN

This was an internet survey, using the REDCap application, of women who underwent POC, at a single-centre university-affiliated IVF unit, 4-8 years before the survey. The questionnaire addressed reproductive choices and outcomes following POC.

RESULTS

Seventy-nine women who underwent POC during 2011-2014 were invited to participate, and 70 (89%) responded. Mean age at cryopreservation was 37.1 ± 2.4 (range 30-41) years, mean age at study participation 42.6 ± 2.6 (range 35-48) years, and mean time from first cryopreservation cycle to study participation 5.5 ± 1.3 (range 4-8) years. The main retrospectively reported reason for POC was not wanting to become pregnant without a partner (59, 84%). During the follow-up period, 44 women (63%) attempted to conceive either naturally or by assisted reproductive technology using fresh or cryopreserved oocytes. Of those, 28 women achieved a live birth (64% of those who tried to conceive). Fourteen respondents (20% of all respondents) reported using their cryopreserved oocytes, and three (21%) achieved a birth using those oocytes. Fifteen women (34%) of those who tried to conceive used donor spermatozoa.

CONCLUSIONS

The most common reasons for not using frozen oocytes were achieving pregnancy without frozen oocytes or preferring not to have a child without a partner. A considerable proportion of women who had POC and were not interested in being a single parent by choice eventually try to conceive using donor spermatozoa several years later.

Disposition intentions of elective egg freezers toward their surplus frozen oocytes: a systematic review and meta-analysis

OBJECTIVE

To examine the disposition outcomes and disposition intentions of elective egg freezers (EEFs) toward their surplus frozen oocytes and the psychosocial determinants underlying these.

DESIGN

A systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Actual EEFs (women with oocytes in storage), potential EEFs (women investigating elective oocyte cryopreservation or about to freeze their oocytes), and women of reproductive age (women in the community aged ≥18 years).

INTERVENTION(S)

A systematic review was undertaken and electronically searched MEDLINE, Embase, and PsycINFO on the Ovid platform for conference abstracts and peer-reviewed articles, published in English after January 1, 2010. A search strategy combined synonyms for oocyte, cryopreservation, donation, disposition, elective, and attitude. Eligible studies assessed disposition outcomes (how an oocyte was disposed of) and disposition intentions (how women intend to dispose of an oocyte) and/or the psychosocial determinants underlying disposition outcomes and intentions. The Joanna Briggs Institute Prevalence Tool was used to assess the risk of bias. A meta-analysis using random effects was applied to pool proportions of women with similar disposition intentions toward their oocytes.

MAIN OUTCOME MEASURE(S)

Disposition outcomes and intentions toward surplus frozen oocytes: donate to research; donate to others; discard; unsure. Psychosocial determinants (beliefs, attitudes, barriers, and facilitators) of disposition outcomes and intentions.

RESULT(S)

A total of 3,560 records were identified, of which 22 (17 studies) met the inclusion criteria (8 studies from Europe, 7 from North America, and 2 from Asia). No studies reported on past oocyte disposition outcomes. Seventeen studies reported on the future disposition intentions of 5,446 women. Only 2 of the 17 studies reported on the psychosocial determinants of oocyte disposition intentions. There was substantial heterogeneity in the pooled results, which was likely a result of the significant variation in methodology. Actual EEFs were included in eight studies (n = 873), of whom 53% (95% confidence interval [CI], 44-63; I², 87%) would donate surplus oocytes to research, 31% (95% CI, 23-40; I², 72%) were unsure, 26% (95% CI, 17-38; I², 92%) would donate to others, and 12% (95% CI, 6-21; I², 88%) would discard their eggs. Psychosocial determinants: One study reported that 50% of these women were aware of friends and/or family having difficulty conceiving, which may have contributed to their willingness to donate to others. Potential EEFs were included in 4 studies (n = 645), of whom 38% (95% CI, 28-50; I², 84%) would donate to research, 32% (95% CI, 17-51; I², 91%) would donate to others, 29% (95% CI, 17-44; I², 89%) would discard, and 7% (95% CI, 1-27; I², 77%) were unsure. Psychosocial determinants: No studies. Women of reproductive age were included in 5 studies (n = 3,933), of whom 59% (95% CI, 48-70; I², 97%) would donate to research and 46% (95% CI, 35-57; I², 98%) would donate to others. "Unsure" and "discard" were not provided as response options. Psychosocial determinants: One study reported that the facilitators for donation to others included a family member or friend in need, to help others create a family, financial gain, to further science, and control or input over the selection of recipients. Barriers for donation included fear of having a biological child they do not know or who is raised by someone they know.

CONCLUSION(S)

No studies reported on the disposition outcomes of past EEFs. Disposition intentions varied across the three groups; however, "donating to research" was the most common disposition preference. Notably, the second disposition preference for one-third of actual EEFs was "unsure" and for one-third of potential EEFs was "donate to others." There were limited studies for actual and potential EEFs, and only two studies that explored the psychosocial determinants of oocyte disposition intentions. Additionally, these data suggest that disposition decisions change as women progress on their egg freezing journey, highlighting the importance of ongoing contact with the fertility team as intentions may change over time. More research is needed to understand the psychosocial determinants of oocyte disposition decisions so fertility clinics can provide EEFs with the support and information they need to make informed decisions about their stored eggs and reduce the level of uncertainty reported among EEFs and the potential risk of psychological distress and regret.

CLINICAL TRIAL REGISTRATION NUMBER

PROSPERO 2020: CRD42020202733.

Employer-Sponsored Egg Freezing: Carrot or Stick?

BACKGROUND

Since 2014, many companies have followed the lead of Apple and Facebook and now offer financial support to female employees to access egg freezing. Australian companies may soon make similar offers. Employer-sponsored egg freezing (ESEF) has raised concerns and there is academic debate about whether ESEF promotes reproductive autonomy or reinforces the 'career vs. family' dichotomy. Despite the growing availability of ESEF and significant academic debate, little is known about how ESEF is perceived by the public. The aim of this study was to explore women's attitudes toward ESEF.

METHODS

Women aged 18-60 years who resided in Victoria, Australia were invited to complete an online, cross-sectional survey investigating views toward egg freezing. Associations between participant demographics and their views about ESEF were assessed using multinominal logistic regression, adjusted for age and free text comments were analyzed using thematic analysis.

RESULTS

The survey was completed by 656 women, median age 28 years (range: 18-60 years). Opinions on the appropriateness of employers offering ESEF were divided (Appropriate: 278, 42%; Inappropriate: 177, 27%; Unsure: 201, 31%). There was significantly less support for ESEF among older participants and those employed part-time (p < 0.05). While some participants saw the potential for ESEF to increase women's reproductive and career options, others were concerned that ESEF could pressure women to delay childbearing and exacerbate existing inequities in access to ARTs.

CONCLUSIONS

Our analysis revealed that while some women identified risks with ESEF, for many women ESEF is not viewed as theoretically wrong, but rather it may be acceptable under certain conditions; such as with protections around reproductive freedoms and assurances that ESEF is offered alongside other benefits that promote career building and family. We suggest that there may be a role for the State in ensuring that these conditions are met.

A major increase in oocyte cryopreservation cycles in the USA, Australia and New Zealand since 2010 is highlighted by younger women but a need for standardized data collection

STUDY QUESTION

What are the cohort trends of women undergoing oocyte cryopreservation (OC)?

SUMMARY ANSWER

There has been a dramatic increase in OC cycles undertaken each year since 2010, and the demographics of women accessing OC has shifted to a younger age group, but so far very few women have returned to use their cryopreserved oocytes in treatments.

WHAT IS KNOWN ALREADY

Although OC, as a method of fertility preservation, is offered around the world, global data are lacking on who is accessing OC, who is returning to thaw oocytes and whether these trends are changing.

STUDY DESIGN, SIZE, DURATION

A trinational retrospective cohort study was performed of 31 191 OC cycles and 972 oocyte thaw (OT) cycles undertaken in the USA (2010-2016) and 3673 OC and 517 OT cycles undertaken in Australia/New Zealand (Aus/NZ; 2010-2015).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were obtained from the USA Society for Assisted Reproductive Technology (SART) national registry and the Australian and New Zealand Assisted Reproduction Database (ANZARD). De-identified data were requested on all autologous oocyte freeze-all cycles and all cycles where autologous oocytes were thawed to be used in a treatment cycle for the time periods of interest.

MAIN RESULTS AND THE ROLE OF CHANCE

In both the USA and Aus/NZ, there has been a dramatic rise in the number of OC cycles performed each year (+880% in the USA from 2010 to 2016 and +311% in Aus/NZ from 2010 to 2015). Across both regions, most women undergoing OC were aged in their late 30s, but the average age decreased over time (USA: 36.7 years vs 34.7 years in 2010 and 2016, respectively). The number of women returning for thaw cycles was low (USA: 413 in 2016, Aus/NZ: 141 in 2015) and most thaw cycles (47%) across both regions involved oocytes that were frozen for <6 months. In the USA, a higher proportion of cycles resulted in a live birth when only thawed oocytes were used, compared to cycles that combined thawed oocytes with fresh oocytes (25% vs 11%, respectively; P < 0.001). Age at retrieval influenced live birth rate in the USA; 38% of thaw cycles started in women who stored oocytes when aged ≤35 years resulted in a live birth, whereas only 16% resulted in a live birth for women who stored oocytes when aged ≥36 years. Similar data were unobtainable from Aus/NZ.

LIMITATIONS, REASONS FOR CAUTION

There were limitations associated with both the SART and ANZARD data outputs received. The format in which the ANZARD data were provided, and the inconsistencies seen amongst cycle reporting in the SART dataset, restricted data interpretation. For example, both datasets did not provide a clear indication as to why women were undergoing OC and it was not possible to accurately calculate duration of storage for thaw cycles in the USA. We also did not obtain details on embryo quality from either database and acknowledge that embryo quality and subsequent outcome (embryo freezing or discard) would be of interest, especially when considering the efficacy of OC.

WIDER IMPLICATIONS OF THE FINDINGS

The data show that there is widespread demand for OC, and it is increasingly undertaken by younger women; however, the limitations encountered in the dataset support the need for a shift to a more uniform approach to data collection and presentation by large databases, worldwide.

STUDY FUNDING/COMPETING INTEREST(S)

This study received funding from the Fertility Society of Australia to support the ANZARD data extraction. M.J. is supported by an Australian Government Research Training Program Scholarship stipend. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

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.

Planned oocyte cryopreservation (Planned OC): systematic review and meta-analysis of cost-efficiency and patients' perspective

BACKGROUND

Advances in vitrification techniques have enabled planned oocyte cryopreservation ('Planned OC').

OBJECTIVES

To explore the cost-efficiency and utilisation of planned OC, as well as patients' perspectives on the process.

SEARCH STRATEGY

A systematic search in PubMed/MEDLINE, Embase, Cochrane Database and PsychINFO, for all relevant studies published between January 2007 and December 2019.

SELECTION CRITERIA

The protocol followed PRISMA guidelines in PECO format, and was registered with PROSPERO.

DATA COLLECTION AND ANALYSIS

Two independent reviewers evaluated all manuscripts for inclusion eligibility. Authors were contacted for missing data. Included studies were assessed for risk of bias and for heterogeneity. Weighted effects were measured and plotted.

MAIN RESULTS

The search yielded 12 545 records, of which 43 were included. Planned OC is cost-efficient at 35, assuming 60% utilisation; and at 37 assuming utilising donor sperm when necessary. At 38 it is cost-efficient to defer planned OC in favour of undergoing 2 IVF cycles. Currently, utilisation of banked-oocytes within 22-58 months, is up to 15%. Nine percent of warmed banked oocytes result in life births. Online resources and treating physicians are equally important sources of information regarding planned OC. Most patients think planned OC is ideal before age 35 and are not fully aware of what the process entails and tend to overestimate the success rates. The main barrier to wider endorsement of planned OC is being wary of potential health implications or of limited success.

CONCLUSION

Planned OC is an adequate method for preserving fertility. However, knowledge gaps result in under-utilisation leading to reduced cost-efficiency.

TWEETABLE ABSTRACT

Identifying facilitators and barriers for wider adoption of banking oocytes can enhance the cost-efficiency of this modality.

Social freezing of oocytes: a means to take control of your fertility

In the last few decades, there have been tremendous developments of assisted reproductive technologies, but the outcome of in vitro fertilization is highly dependent on the age of the oocyte. The introduction of vitrification offers a possibility to freeze eggs proactively in younger years and use them at later ages, also called social egg freezing. Knowledge about age-related fertility decline is insufficient among many women, and there is an overoptimistic trust that in vitro fertilization can overcome this. The awareness of proactive egg freezing is limited, both among doctors and in the general population. This review aims at increasing the knowledge about proactive egg freezing and offers a means to advise women correctly. It deals with national guidelines, the best age and optimal number of eggs to freeze, and the chance to succeed. Creating more public awareness about age-linked fertility decline and elective egg freezing may help women reproduce at their own pace - to take control of their fertility.