Why all women should freeze their eggs

Women's reproductive choice and (elective) egg freezing: is an extension of the storage limit missing a bigger issue?

Egg freezing can allow women to preserve their eggs to avoid age-related infertility. The UK's recent extension of elective egg freezing storage has been welcomed as a way of enhancing the reproductive choices of young women who wish to delay having children. In this paper, I explore the issue of enhancing women's reproductive choices, questioning whether there is a more significant aspect overlooked in egg freezing. While increasing storage limits expands reproductive choices for some women, focus on this extension alone, I argue, misses a fundamental issue with egg preservation that often remains ignored; the importance of effective information on egg freezing and the effect this has on women's reproductive choices. Ultimately, I highlight the crucial role of balanced information in enhancing women's choices regarding egg freezing and argue that focusing on extending and increasing provision may obscure this real opportunity to empower women and their authentic reproductive choices.

Planned oocyte cryopreservation to preserve future reproductive potential: an Ethics Committee opinion

Planned oocyte cryopreservation is an ethically permissible procedure that may help individuals avoid future infertility. Because planned oocyte cryopreservation is new and evolving, it is essential that those considering using it be informed about the uncertainties regarding its efficacy and long-term effects. This replaces the document of the same name, last published in 2017.

Diagnostic significance of neutrophil to lymphocyte ratio in endometriosis: a systematic review and meta-analysis

BACKGROUND

The purpose of this systematic review and meta-analysis was to compile existing evidence on the significance of the NLR in predicting endometriosis in order to aid clinical decision-making and outcomes.

METHODS

We searched ProQuest, Web of Science, and PubMed for related studies published before January 2, 2023. Standardized mean difference (SMD) with a 95% confidence interval (CI) was reported for each outcome. Because a significant level of heterogeneity was found, we used the random-effects model to calculate pooled effects. We used Newcastle-Ottawa Scale (NOS) for quality assessment.

RESULTS

Overall, 18 article with were included in the analysis. A random-effect model revealed that patients with endometriosis had elevated levels of NLR compared to healthy controls (SMD = 0.79, 95% CI = 0.33 to 1.25, P < 0.001). Patients with endometriosis had elevated levels of NLR compared to those with other benign tumors (SMD = 0.85, 95% CI = 0.17 to 1.53, P = 0.014). In addition, NLR level of patients with stage III and IV endometriosis was not different from that of patients with stage I and II endometrioma (SMD = 0.30, 95% CI = -0.14 to 0.74, P = 0.18). However, NLR level was not different between endometriosis patients with and without peritoneal lesions (SMD = -0.12, 95% CI = -0.34to 0.10, P = 0.28), between patients with and without endometrioma (SMD = 0.20, 95% CI = -0.15 to 0.55, P = 0.26) and between endometriosis patients with and without deep lesions (SMD = 0.04, 95% CI = -0.20 to 0.28, P = 0.72). The pooled sensitivity of NLR was 0.67 (95% CI = 0.60-0.73), and the pooled specificity was 0.68 (95% CI, 0.62-0.73).

CONCLUSIONS

NLR might be utilized in clinics as a possible predictor to help clinicians diagnose endometriosis in affected women.

Involvement of PINK1/Parkin-mediated mitophagy in mitochondrial functional disruption under oxidative stress in vitrified porcine oocytes

Vitrification is an effective technique for fertility preservation, but is known to lead to mitochondrial dysfunction in porcine oocytes. Mitophagy is induced to rebalance mitochondrial function, a process in which reactive oxygen species (ROS) plays a role. In this study, vitrified-warmed porcine oocytes were incubated for 4 h with the oxidant AAPH or antioxidant α-tocopherol to alter ROS levels. A series of tests suggested that vitrification damaged mitochondrial structure and caused dysfunction, including blurred mitochondrial cristae, decreased mitochondrial membrane potential, decreased mtDNA copy number and increased ROS generation. This dysfunction resulted in mitophagy and the loss of embryonic developmental potential. Incubation with AAPH or α-tocopherol altered mitochondrial function and mitophagy flux status in vitrified oocytes. The PINK1/Parkin pathway was involved in oxidative stress regulation in vitrified oocytes. Under AAPH-induced oxidative stress, increased fluorescence intensity of Parkin, increased expression of PINK1, Parkin, and LC3B-II, and decreased expression of MFN2 and p62 were observed, whereas the opposite effects were induced under α-tocopherol treatment. The inhibition of ROS by α-tocopherol benefitted mitochondrial homeostasis and alleviated PINK1/Parkin-mediated mitophagy, resulting in the recovery of embryonic developmental potential in vitrified porcine oocytes. Therefore, this study provides a new mechanism for the application of antioxidants to aid the cryopreservation of porcine oocytes.

'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.

Mitophagy is involved in the mitochondrial dysfunction of vitrified porcine oocytes

Mitochondrial dysfunction is considered a crucial factor aggravating oocyte viability after vitrification-warming. To clarify the role of mitophagy in mitochondrial extinction of vitrified porcine oocytes, mitochondrial function, ultrastructural characteristics, mitochondria-lysosomes colocalization, and mitophagic proteins were detected with or without chloroquine (CQ) treatment. The results showed that vitrification caused mitochondrial dysfunction, including increasing reactive oxygen species production, decreasing mitochondrial membrane potential, and mitochondrial DNA copy number. Damaged mitochondrial cristae and mitophagosomes were observed in vitrified oocytes. A highly fused fluorescence distribution of mitochondria and lysosomes was also observed. In the detection of mitophagic flux, mitophagy was demonstrated as increasing fluorescence aggregation of microtubule-associated protein light chain 3B (LC3B), enhanced colocalization between LC3B, and voltage-dependent anion channels 1 (VDAC1), and upregulated LC3B-II/I protein expression ratio. CQ inhibited the degradation of mitophagosomes in vitrified oocytes, manifested as decreased mitochondria-lysosomes colocalization, increased fluorescence fraction of VDAC1 overlapping LC3B, increased LC3B-II/I protein expression ratio, and p62 accumulation. The inhibition of mitophagosomes degradation by CQ aggravated mitochondrial dysfunction, including increased oxidative damage, reduced mitochondrial function, and further led to loss of oocyte viability and developmental potentiality. In conclusion, mitophagy is involved in the regulation of mitochondrial function during porcine oocyte vitrification.

A Survey of Women Who Cryopreserved Oocytes for Non-medical Indications (Social Fertility Preservation)

To evaluate the expectations, experiences, and fertility awareness status of women who underwent social oocyte cryopreservation. Cohort survey study was conducted at an academic medical center. All women who underwent social oocyte cryopreservation between January 2015 and June 2016 were recruited. One hundred thirty-three women were contacted by phone to participate in a survey. The questionnaire investigated the initial motivation towards freezing, intentions to use cryopreserved oocytes, treatment experience, awareness of fertility and knowledge about chances of having a live birth with their frozen oocytes. The mean age at the time of oocyte freezing was 38.5 ± 2.68 years. The average number of mature oocytes cryopreserved was 5.48 ± 6.6 (1-16). Two major motivations were absence of a male partner (40%) and an anticipated age-related fertility decline (42%). Almost 60% overestimated the chances of natural conception, as well as the success of IVF at the age of 40 years. Half of the oocyte bankers reported that fertility declined between ages 35 and 39, but only 28% of patients estimated the live birth rate per cryopreserved oocyte correctly. Overall 98.8% stated that they would recommend oocyte cryopresevation to a friend, and 72% felt more secure in terms of reproductive potential. Despite comprehensive personalized counseling prior to the start of ovarian stimulation, many women do not seem to have a realistic understanding of reproductive aging. Even though gamete cryopreservation provides some insurance, overestimating the effectiveness of oocyte cryopreservation can also lead to a false sense of security. Clinical Trial Registration: 2016.086.IRB1.006.

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.

Oocyte vitrification for fertility preservation in women with endometriosis: an observational study

OBJECTIVE

To describe the outcome of fertility preservation (FP) using vitrified oocytes in patients with endometriosis and to determine the impact of ovarian surgery.

DESIGN

Retrospective observational study.

SETTING

University-affiliated private in vitro fertilization (IVF) center.

PATIENT(S)

Four hundred and eighty-five women with endometriosis who underwent FP from January 2007 to July 2018.

INTERVENTION(S)

Vitrification of metaphase II (MII) oocytes for future use.

MAIN OUTCOME MEASURE(S)

Oocyte survival rate and cumulative live-birth rate (CLBR).

RESULT(S)

Mean age at vitrification was 35.7 ± 3.7 years. The women undergoing operations were younger than the nonsurgical patients (33.4 ± 3.6 years vs. 36.7 ± 3.7 years). The survival rate and CLBR were 83.2% and 46.4%, respectively. The number of vitrified oocytes per cycle (6.2 ± 5.8) was higher for the nonsurgical patients compared with the unilateral (5.0 ± 4.5) or bilateral (4.5 ± 4.4) surgery groups, but was comparable among the surgical patients. The effect of age (adjusted odds ratio [OR] 0.904; 95% CI, 0.858-0.952), number of oocytes (adjusted OR 1.050; 95% CI, 1.025-1.091), and survival (adjusted OR 1.011; 95% CI, 1.001-1.020) on the CLBR was confirmed. However, the effect of surgery was not observed (adjusted OR 1.142; 95% CI, 0.778-1.677). Nonetheless, the ovarian response (vitrified oocytes = 8.6 ± 6.9 vs. 5.1 ± 4.8) and CLBR (72.5% vs. 52.8%) were higher in young (≤35 years) nonsurgical patient versus the surgical patients; older women showed similar outcomes.

CONCLUSION(S)

Fertility preservation gives patients with endometriosis a valid treatment option to help them increase their reproductive chances. We suggest performing surgery after ovarian stimulation for FP in young women. In older women, an individualized treatment should be considered.

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.

For whom the egg thaws: insights from an analysis of 10 years of frozen egg thaw data from two UK clinics, 2008-2017

PURPOSE

To better understand the characteristics of patients who returned to thaw their frozen eggs to attempt conception and their outcomes.

METHODS

A retrospective analysis of clinical records for all own egg thaw patients in two UK fertility clinics across 10 years, 2008-2017.

RESULTS

There were 129 patients who returned to thaw their eggs, of which 46 had originally frozen their eggs for social reasons and 83 for a variety of clinical, incidental, and ethical reasons (which we have called "non-social"). Women who had frozen their eggs for social reasons were single at time of freeze, with an average age of 37.7. They kept their eggs in storage for just under 5 years, returning to use them at the average age of 42.5. 43.5% were single at time of thaw, and 47.8% used donor sperm to fertilise their eggs. Women whose eggs were frozen for non-social reasons were almost all (97.6%) in a relationship at both time of freeze and thaw. They had an average age of 37.2 at first freeze and 37.6 at thaw, having kept their eggs in storage for an average of 0.4 years. Overall, there was a 20.9% success rate among women attempting conception with frozen-thawed eggs.

CONCLUSIONS

Despite widespread assumptions, many women attempting conception with thawed eggs had not initially frozen them for social reasons. Women who froze their eggs for social reasons presented distinctly and statistically different characteristics at both time of freeze and thaw to women whose eggs were frozen for non-social reasons.

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.

What advice should we give our patients to preserve their fertility and avoid needing oocyte donation in the future? - A Social Fertility Preservation program

OBJECTIVE

To describe our fertility preservation program focusing on the number of oocytes vitrified by age.

METHODS

From January 2015 to December 2016, 686 oocyte vitrification cycles were performed in our units for the social fertility preservation program. In total, 288 were donors who donated their oocytes for our oocyte-banking program, and 398 were patients who underwent elective fertility preservation.

RESULTS

The mean numbers of COCs retrieved and vitrified oocytes were similar among the donor cycles (women under 30 years). In those patients over 36 years of age the mean numbers of COCs retrieved and vitrified oocytes were significantly lower. We also estimated the association between age and cancelation rates. Odd ratios (OR) for total cancelation was calculated between patients of 31-35 years and 41-45 years; the OR was 5.17 (95% CI 1.89 - 14.17) and increased up to 25.67 (95% CI 5.01 - 131.42) between patients 31-35 y and those older than 45 years. No differences were found between patients of 31-35 years and 36-40 years. The OR for total cancellation increased 3.83 (95% CI 2.06 - 7.11) and 19.00 (95% CI 4.56 - 79.11) between women 36-40 years and 41-45 years, and those older than 45 years, respectively. Finally, the oocyte survival rate in patients under 36 years of age was similar to that of our donor program (94% vs. 95%).

CONCLUSIONS

Based on this study, we encouraged our patients under than 36 years of age to preserve their fertility for the future.

Preservation of female fertility in humans and animal species

A detailed understanding of the cryobiology of gametes and complex tissues has led to the development of methods that facilitate the successful low temperature banking of isolated mature human oocytes, or immature oocytes in situ within fragments of human ovarian cortex. Although many outstanding research challenges remain to be addressed, the successful development of new treatments to preserve female fertility for a range of clinical indications has largely been underpinned by the conduct of extensive, fundamental research on oocytes and ovarian tissues from a number of laboratory and commercially important farm species. Indeed, the most recent evidence from large animals suggests that it is also possible to cryopreserve intact whole ovaries along with their supporting vasculature for later auto-transplantation and restoration of natural fertility. This review will explore how the methods developed to preserve human oocytes and ovarian tissues can now be used strategically to support the development of conservation strategies aimed at safeguarding the genetic diversity of commercially important domestic animals and also of preserving the female germplasm for wild animals and endangered species.

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.

A new, simple, automatic vitrification device: preliminary results with murine and bovine oocytes and embryos

PURPOSE

This paper reports the use of a novel automatic vitrification device (Sarah, Fertilesafe, Israel) for cryopreservation of oocytes and embryos.

METHODS

Mice oocytes (n = 40) and embryos (8 cells, n = 35 and blastocysts, n = 165), bovine embryos (2PN, n = 35), and MII oocytes (n = 84) were vitrified using this automated device. A total of 42 (2 cells) mice embryos, 20 (2PN) bovine embryos, and 150 MII bovine oocytes were used as fresh controls and grown to blastocysts. Upon rewarming, all were assessed for viability, cleavage, blastocyst, and hatching rates.

RESULTS

Ninety-five % (38/40) of the mice MII oocytes regained isotonic volumes and all (100%) the surviving were viable. Rewarmed 8-cell mice embryos had 95% (33/35) blastulation rate and 80% (28/35) hatched. Rewarmed mice blastocysts had 97% survival rate (160/165) and 81% (135/165) hatched. Fresh control mice embryos had 100% (42/42) blastulation and 73% (21/42) hatching rates. Bovine embryos' survival was 100% with 54% (19/35) cleavage and 9% (3/35) blastulation rate. Fresh control bovine embryos had 65% (13/20) cleavage and 20% (4/20) blastulation rate. Vitrified bovine oocytes had 100% survival (84/84), 73% (61/84) cleavage, and 7% (6/84) blastocysts' rates; fresh control had 83% (125/150) cleavage and 11% (17/150) blastocysts' rates.

CONCLUSION

This novel automatic vitrification device is capable to produce high survival rates of oocytes and embryos. We anticipate that as the demand for vitrification of gametes, embryos, and reproductive tissues increases worldwide, the availability of an automated vitrification device will become indispensable for standardization, simplification, and reproducibility of the entire process.

Reproductive experiences of women who cryopreserved oocytes for non-medical reasons

STUDY QUESTION

What are the reproductive experiences of women who cryopreserve oocytes for non-medical reasons?

SUMMARY ANSWER

One in three women had been pregnant at some stage in their lives and while most still wanted to have a child or another child, very few had used their stored oocytes, predominantly because they did not want to be single parents.

WHAT IS KNOWN ALREADY

The number of healthy women who freeze oocytes to avoid age-related infertility is increasing. Evidence about reproductive outcomes after oocyte cryopreservation for non-medical reasons is needed to help women make informed decisions.

STUDY DESIGN SIZE, DURATION

A cross-sectional survey was carried out. Study packs which included a self-administered questionnaire were mailed by clinic staff to 193 eligible women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women who had stored oocytes for non-medical reasons at Melbourne IVF, a private ART clinic, between 1999 and 2014 were identified from medical records and invited to complete an anonymous questionnaire about their reproductive histories and experience of oocyte cryopreservation.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 10 survey packs were returned to the clinic marked 'address unknown'. Of the 183 potential respondents, 96 (53%) returned the questionnaire. One respondent provided only free-text comments, thus data from 95 respondents were compiled. The mean age at the time of freezing oocytes was 37.1 years (SD ± 2.6, range: 27-42) and the average number of oocytes stored was 14.2 (SD ± 7.9, range: 0-42); 2% had attempted to store oocytes but had none suitable for freezing, 24% had stored <8 oocytes, 35% had 8-15, 25% had 16-23 and 14% had stored >23 oocytes. About one-third of respondents (34%) had been pregnant at some point in their lives. Six women (6%) had used their stored oocytes and three of them had given birth as a result. The main reason for not using stored oocytes was not wanting to be a single parent. Of the 87 (91%) women who still had oocytes stored, 21% intended to use them while 69% indicated that their circumstances would determine usage. The mean number of children respondents would ideally have liked to have was significantly higher than the number of children they expected to have (2.11 versus 1.38, P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

The limitations are inherent to any anonymously completed questionnaire: participation bias, missing data and the possibility that some questions or response alternatives may have been ambiguous.

WIDER IMPLICATIONS OF THE FINDINGS

The findings add to the very limited evidence about the reproductive outcomes experienced by women who freeze oocytes for non-medical reasons and can be used to help women make informed decisions about whether to store oocytes.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Melbourne IVF. K.H. has received honoraria from Merck-Serono, J.M. is a clinician at Melbourne IVF, F.A. is a Melbourne IVF employee, J.F. is supported by a Monash Professorial Fellowship and the Jean Hailes Professorial Fellowship which receives funding from the L and H Hecht Trust, managed by Perpetual Trustees Pty Ltd. M.K., N.P., M.H., M.P. and C.B. have no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.

Cryopreservation of Ovarian Tissue: Opportunities Beyond Fertility Preservation and a Positive View Into the Future

In current years, ovarian tissue cryopreservation (OTC) and transplantation is gaining ground as a successful method of preserving fertility in young women with primarily cancer diseases, hereby giving them a chance of becoming biological mothers later on. However, OTC preserves more than just the reproductive potential; it restores the ovarian endocrine function and thus the entire female reproductive cycle with natural levels of essential hormones. In a female population with an increased prevalence in the loss of ovarian function due to induced primary ovarian insufficiency (POI) and aging, there is now, a need to develop new treatments and provide new opportunities to utilize the enormous surplus of follicles that most females are born with and overcome major health issues associated with the lack of ovarian hormones. Cell/tissue-based hormone replacement therapy (cHRT) by the use of stored ovarian tissue could be one such option comprising both induction of puberty in prepubertal POI girls, treatment of POI and premature menopause, and as primary prevention at the onset of menopause. In the current review, we explore known and entirely new applications for the potential utilization of OTC including cHRT, social freezing, culture of immature oocytes, and a modern ovarian resection for women with polycystic ovaries, and discuss the indications hereof.

Effect of oocyte vitrification on embryo quality: time-lapse analysis and morphokinetic evaluation

OBJECTIVE

To analyze whether oocyte vitrification may affect subsequent embryo development from a morphokinetic standpoint by means of time-lapse imaging.

DESIGN

Observational cohort study.

SETTING

University-affiliated private IVF center.

PATIENT(S)

Ovum donation cycles conducted with the use of vitrified (n = 631 cycles; n = 3,794 embryos) or fresh oocytes (n = 1,359 cycles; n = 9,935 embryos) over 2 years.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

Embryo development was analyzed in a time-lapse imaging incubator. The studied variables included time to 2 cells (t2), 3 cells (t3), 4 cells (t4), 5 cells (t5), morula (tM), and cavitated, early, and hatching blastocyst (tB, tEB, tHB) as well as 2nd cell cycle duration (cc2 = t3 - t2). All of the embryos were classified according to the hierarchic tree model currently used for embryo selection. The analyzed variables were compared with the use of analysis of variance or chi-square and included 95% confidence intervals (CIs).

RESULT(S)

The embryos that originated from vitrified oocytes showed a delay of ∼1 hour from the first division to 2 cells (t2) to the time of blastulation (tB). The embryos that originated from vitrified oocytes showed a delay of ∼1 hour from the 1st division to 2 cells (t2) to the time of blastulation (tB) (P<.05). The proportions of embryos allocated to categories A-E in the hierarchical tree were similar between groups. No differences in implantation rates between the fresh (51.3% [95% CI 47.1%-55.7%]) and vitrified (46.4% [95% CI 38.4%-54.4%]) groups were found.

CONCLUSION(S)

The embryo quality of vitrified oocytes was not impaired: cc2, quality according to our hierarchic morphokinetic model, and implantation rates were similar between fresh and vitrified oocytes. However, morphokinetic differences were observed from t2 to tB. Our main study limitation was the retrospective nature of the analysis, although a large database was studied.

Random-start ovarian stimulation in women desiring elective cryopreservation of oocytes

The current study investigates the utility of random-start ovarian stimulation in women desiring elective oocyte cryopreservation. Women in the study cohort underwent random-start ovarian stimulation, and were subdivided based on the phase of the menstrual cycle that ovarian stimulation began, i.e. early follicular, late follicular or luteal phase. Women undergoing conventional cycle day (CD) 2/3 ovarian stimulation start were controls. A total of 1302 women were included - 859 (66.0%) conventional CD 2/3, 342 (26.3%) early follicular, 42 (3.2%) late follicular and 59 (4.5%) luteal ovarian stimulation starts. There was no difference in the demographics or baseline ovarian stimulation characteristics. The duration of ovarian stimulation (11 versus 9 days; P < 0.001) and total dosage of gonadotrophins administered (4095.5 versus 3155 IU; P < 0.001) was higher in the random-start group. The number of total and MII oocytes in the control and random-start groups was similar. A non-significant trend towards increased cycle cancellation was noted in the late follicular start group (7.1%). Study findings indicate the number of total and MII oocytes derived from random-start protocols initiated during any phase of the menstrual cycle is similar to conventional CD 2/3 ovarian stimulation start protocols in women desiring elective oocyte cryopreservation.

Is employer coverage of elective egg freezing coercive?: a survey of medical students' knowledge, intentions, and attitudes towards elective egg freezing and employer coverage

PURPOSE

The purpose of this study was to understand medical students' knowledge, intentions, and attitudes towards oocyte cryopreservation and employer coverage of such treatment.

METHODS

This cross-sectional study was performed via an online cross-sectional survey distributed to 280 female medical students from March through August 2016. Demographics, attitudes towards employer coverage, and factors influencing decision-making were assessed via a self-reported multiple-choice questionnaire. The relationship between respondents' attitudes towards employer coverage and other parameters was analyzed.

RESULTS

A total of 99 responses were obtained out of 280 female medical students. Most respondents (71%) would consider oocyte cryopreservation (potential freezers), although 8% would not consider the procedure and 21% were unsure. Seventy-six percent of respondents felt pressure to delay childbearing. Potential freezers were more likely to be single (p = 0.001), to report feeling pressure to delay childbearing (p = 0.016), and to consider egg freezing if offered by an employer (p < 0.001). Importantly, 71% percent did not view employer coverage as coercive and 77% of respondents would not delay childbearing due to employer coverage. Factors influencing decision-making in potential freezers were absence of a suitable partner (83%), likelihood of success (95%), and health of offspring (94%), among others. Knowledge about the low chance of pregnancy per oocyte (6-10%) would influence decision-making in 42% of potential freezers.

CONCLUSION

Oocyte freezing is an acceptable strategy for the majority of young women surveyed. Pressure to delay childbearing was related to openness to freeze eggs. The majority of respondents did not find employer coverage for egg freezing coercive although further research is needed with larger, representative samples to ascertain the relationship between pressure to delay childbearing due to work demands and employer coverage for egg freezing.

Are there optimal numbers of oocytes, spermatozoa and embryos in assisted reproduction?

The aim of this overview is to discuss the current information about the search for the optimum yield of gametes in assisted reproduction, as one of the major pillars of IVF success. The first topic is focused on the number of male gametes and the possible impact of some genetic traits on these parameters. The number of spermatozoa did not seem to be crucial when there is no severe male factor of infertility. Genetic testing prior to using those sperm cells is very important. Different methods were applied in order to elect the "best" spermatozoa according to specific indications. The next problem discussed is the importance of the number of oocytes collected. Several studies have agreed that "15 oocytes is the perfect number," as the number of mature oocytes is more important. However, if elective single embryo transfer is performed, the optimal number of oocytes will enable a proper embryo selection. The third problem discussed concerns fertility preservation. Many educational programs promote and encourage procreation at maternal ages between 20-35 years, since assisted reproduction is unable to fully overcome the effects of female aging and fertility loss after that age. It is also strongly recommended to ensure a reasonable number of cryopreserved mature oocytes, preferably in younger ages (<35), for which an average of two stimulation cycles are likely required. For embryo cryopreservation, the "freeze all" strategy suggests the vitrification of good embryos, therefore quality is prior to number and patient recruitment for this strategy should be performed cautiously.