Implicit bias in diagnosing mosaicism amongst preimplantation genetic testing providers: results from a multicenter study of 36 395 blastocysts.

STUDY QUESTION: Does the diagnosis of mosaicism affect ploidy rates across different providers offering preimplantation genetic testing for aneuploidies (PGT-A)? SUMMARY ANSWER: Our analysis of 36 395 blastocyst biopsies across eight genetic testing laboratories revealed that euploidy rates were significantly higher in providers reporting low rates of mosaicism. WHAT IS KNOWN ALREADY: Diagnoses consistent with chromosomal mosaicism have emerged as a third category of possible embryo ploidy outcomes following PGT-A. However, in the era of mosaicism, embryo selection has become increasingly complex. Biological, technical, analytical, and clinical complexities in interpreting such results have led to substantial variability in mosaicism rates across PGT-A providers and clinics. Critically, it remains unknown whether these differences impact the number of euploid embryos available for transfer. Ultimately, this may significantly affect clinical outcomes, with important implications for PGT-A patients. STUDY DESIGN, SIZE, DURATION: In this international, multicenter cohort study, we reviewed 36 395 consecutive PGT-A results, obtained from 10 035 patients across 11 867 treatment cycles, conducted between October 2015 and October 2021. A total of 17 IVF centers, across eight PGT-A providers, five countries and three continents participated in the study. All blastocysts were tested using trophectoderm biopsy and next-generation sequencing. Both autologous and donation cycles were assessed. Cycles using preimplantation genetic testing for structural rearrangements were excluded from the analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: The PGT-A providers were randomly categorized (A to H). Providers B, C, D, E, F, G, and H all reported mosaicism, whereas Provider A reported embryos as either euploid or aneuploid. Ploidy rates were analyzed using multilevel mixed linear regression. Analyses were adjusted for maternal age, paternal age, oocyte source, number of embryos biopsied, day of biopsy, and PGT-A provider, as appropriate. We compared associations between genetic testing providers and PGT-A outcomes, including the number of chromosomally normal (euploid) embryos determined to be suitable for transfer. MAIN RESULTS AND THE ROLE OF CHANCE: The mean maternal age (±SD) across all providers was 36.2 (±5.2). Our findings reveal a strong association between PGT-A provider and the diagnosis of euploidy and mosaicism. Amongst the seven providers that reported mosaicism, the rates varied from 3.1% to 25.0%. After adjusting for confounders, we observed a significant difference in the likelihood of diagnosing mosaicism across providers (P < 0.001), ranging from 6.5% (95% CI: 5.2-7.4%) for Provider B to 35.6% (95% CI: 32.6-38.7%) for Provider E. Notably, adjusted euploidy rates were highest for providers that reported the lowest rates of mosaicism (Provider B: euploidy, 55.7% (95% CI: 54.1-57.4%), mosaicism, 6.5% (95% CI: 5.2-7.4%); Provider H: euploidy, 44.5% (95% CI: 43.6-45.4%), mosaicism, 9.9% (95% CI: 9.2-10.6%)); and Provider D: euploidy, 43.8% (95% CI: 39.2-48.4%), mosaicism, 11.0% (95% CI: 7.5-14.5%)). Moreover, the overall chance of having at least one euploid blastocyst available for transfer was significantly higher when mosaicism was not reported, when we compared Provider A to all other providers (OR = 1.30, 95% CI: 1.13-1.50). Differences in diagnosing and interpreting mosaic results across PGT-A laboratories raise further concerns regarding the accuracy and relevance of mosaicism predictions. While we confirmed equivalent clinical outcomes following the transfer of mosaic and euploid blastocysts, we found that a significant proportion of mosaic embryos are not used for IVF treatment. LIMITATIONS, REASONS FOR CAUTION: Due to the retrospective nature of the study, associations can be ascertained, however, causality cannot be established. Certain parameters such as blastocyst grade were not available in the dataset. Furthermore, certain platform-related and clinic-specific factors may not be readily quantifiable or explicitly captured in our dataset. As such, a full elucidation of all potential confounders accounting for variability may not be possible. WIDER IMPLICATIONS OF THE FINDINGS: Our findings highlight the strong need for standardization and quality assurance in the industry. The decision not to transfer mosaic embryos may ultimately reduce the chance of success of a PGT-A cycle by limiting the pool of available embryos. Until we can be certain that mosaic diagnoses accurately reflect biological variability, reporting mosaicism warrants utmost caution. A prudent approach is imperative, as it may determine the difference between success or failure for some patients. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Torres Quevedo Grant, awarded to M.P. (PTQ2019-010494) by the Spanish State Research Agency, Ministry of Science and Innovation, Spain. M.P., L.B., A.R.L., A.L.R.d.C.L., N.P.P., M.P., D.S., F.A., A.P., B.M., L.D., F.V.M., D.S., M.R., E.P.d.l.B., A.R., and R.V. have no competing interests to declare. B.L., R.M., and J.A.O. are full time employees of IB Biotech, the genetics company of the Instituto Bernabeu group, which performs preimplantation genetic testing. M.G. is a full time employee of Novagen, the genetics company of Cegyr, which performs preimplantation genetic testing. TRIAL REGISTRATION NUMBER: N/A.

Attitude of Belgian women towards enucleated egg donation for treatment of mitochondrial diseases and infertility.

RESEARCH QUESTION: What is the attitude of Belgian women of reproductive age towards enucleated egg donation? Does the willingness of women to donate differ when they would donate enucleated or whole eggs? DESIGN: In 2022, an online survey was conducted among a representative sample of 1000 women in Belgium aged 18-50 years. The item on willingness to anonymously donate enucleated eggs was dichotomized into those willing to donate and those not willing to donate or uncertain. RESULTS: No statistically significant difference was found between the willingness to donate enucleated eggs and whole eggs (whether anonymously or identifiably). Anonymity, however, affected the willingness to donate, with considerably fewer women willing to donate identifiably. The respondents were divided about their parental status if they were to donate enucleated eggs, with less than one-half (44%) not considering themselves to be a genetic mother. Women willing to donate enucleated eggs anonymously were less likely to view themselves as a genetic mother of the child compared with others. Fewer than one in five considered the technique unacceptable because the resulting child would carry genetic material of three persons. CONCLUSIONS: Women in the general population did not show a greater willingness to donate enucleated eggs than whole eggs. The fact that the respondents were strongly divided on whether or not they would consider themselves to be a genetic mother of the resulting child may explain this result. Other factors, such as the potential high risk for the child, may also have contributed to less willingness.

Retained chromosomal integrity following CRISPR-Cas9-based mutational correction in human embryos.

Human germline gene correction by targeted nucleases holds great promise for reducing mutation transmission. However, recent studies have reported concerning observations in CRISPR-Cas9-targeted human embryos, including mosaicism and loss of heterozygosity (LOH). The latter has been associated with either gene conversion or (partial) chromosome loss events. In this study, we aimed to correct a heterozygous basepair substitution in PLCZ1, related to infertility. In 36% of the targeted embryos that originated from mutant sperm, only wild-type alleles were observed. By performing genome-wide double-digest restriction site-associated DNA sequencing, integrity of the targeted chromosome (i.e., no deletions larger than 3 Mb or chromosome loss) was confirmed in all seven targeted GENType-analyzed embryos (mutant editing and absence of mutation), while short-range LOH events (shorter than 10 Mb) were clearly observed by single-nucleotide polymorphism assessment in two of these embryos. These results fuel the currently ongoing discussion on double-strand break repair in early human embryos, making a case for the occurrence of gene conversion events or partial template-based homology-directed repair.

'Do I want children later in life?' Reproductive intentions of 1700 adolescents.

PURPOSE: In the past decades, a positive attitude towards having children has been reported in young people. The current generation of adolescents is increasingly concerned about environmental cataclysm which may have an impact on their desire for children. The purpose of this study is to depict the current attitudes in Flemish adolescents towards having children. MATERIALS AND METHODS: All secondary schools in Flanders (Belgium) were invited to distribute an anonymous online survey among their pupils in the last two years of secondary education. In total, 1700 adolescents participated and provided quantitative and qualitative data on their reproductive intentions. RESULTS: Most pupils expressed a desire for children (60.2%), 24.7% were undecided and 10.8% were not willing to have children. Significantly more boys than girls would like to have children (67.0% versus 61.7%, p < 0.01). Adolescents who were uncertain about having children or not interested, reported financial reasons and loss of freedom as most important reasons. CONCLUSIONS: While most adolescents would like to have children in the future, one in four adolescents is undecided and one in ten indicates a wish to remain childless; reasons for wanting children are rather personal, reasons for not wanting children are rather pragmatic.

A desire for parenthood is no longer the norm: 60% of Flemish adolescents would like to build a family, but many are considering a future without children.

Incidence of and indications for sperm donor restriction - analysis of patients continuing treatment: a retrospective single-centre study.

RESEARCH QUESTION: What are the incidence of and indications for sperm donor restriction due to suspected/confirmed disease risk, and the future treatment choices of patients using these sperm donors? DESIGN: This single-centre retrospective study involved donors who had restrictions on the use of their imported spermatozoa from January 2010 to December 2019, and current or previous recipients. Indications for sperm restriction and the characteristics of patients undergoing medically assisted reproduction (MAR) treatment with these specimens at the time of restriction were collected. Differential characteristics of women who decided on whether or not to contintue the procedure were assessed. Characteristics potentially leading to treatment continuation were identified. RESULTS: Of 1124 sperm donors identified, 200 (17.8%) were restricted, most commonly for multifactorial (27.5%) and autosomal recessive (17.5%) disorders. The spermatozoa had been used for 798 recipients, of whom 172, receiving spermatozoa from 100 donors, were informed about the restriction and constituted the 'decision cohort'. The specimens from the restricted donors were accepted by 71 (approximately 40%) patients, with 45 (approximately 63%) eventually using the restricted donor for their future MAR treatment. The odds of accepting the restricted spermatozoa decreased with increasing age (OR 0.857, 95% CI 0.800-0.918, P < 0.001) and the time between MAR treatment and the restriction date (OR 0.806, 95% CI 0.713-0.911, P < 0.001). CONCLUSION: Donor restriction due to suspected/confirmed disease risk is relatively frequent. This affected a relevant number of women (around 800), of whom 172 (approximately 20%) had to decide whether or not to use these donors further. Although donor screening is being performed thoroughly, there remain health risks for donor children. Realistic counselling of all stakeholders involved is necessary.

Fertility preservation for women with breast cancer: a multicentre randomized controlled trial on various ovarian stimulation protocols.

STUDY QUESTION: Does ovarian stimulation with the addition of tamoxifen or letrozole affect the number of cumulus-oocyte complexes (COCs) retrieved compared to standard ovarian stimulation in women with breast cancer who undergo fertility preservation? SUMMARY ANSWER: Alternative ovarian stimulation protocols with tamoxifen or letrozole did not affect the number of COCs retrieved at follicle aspiration in women with breast cancer. WHAT IS KNOWN ALREADY: Alternative ovarian stimulation protocols have been introduced for women with breast cancer who opt for fertility preservation by means of banking of oocytes or embryos. How these ovarian stimulation protocols compare to standard ovarian stimulation in terms of COC yield is unknown. STUDY DESIGN, SIZE, DURATION: This multicentre, open-label randomized controlled superiority trial was carried out in 10 hospitals in the Netherlands and 1 hospital in Belgium between January 2014 and December 2018. We randomly assigned women with breast cancer, aged 18-43 years, who opted for banking of oocytes or embryos to one of three study arms; ovarian stimulation plus tamoxifen, ovarian stimulation plus letrozole or standard ovarian stimulation. Standard ovarian stimulation included GnRH antagonist, recombinant FSH and GnRH agonist trigger. Randomization was performed with a web-based system in a 1:1:1 ratio, stratified for oral contraception usage at start of ovarian stimulation, positive estrogen receptor (ER) status and positive lymph nodes. Patients and caregivers were not blinded to the assigned treatment. The primary outcome was number of COCs retrieved at follicle aspiration. PARTICIPANTS/MATERIALS, SETTING, METHODS: During the study period, 162 women were randomly assigned to one of three interventions. Fifty-four underwent ovarian stimulation plus tamoxifen, 53 ovarian stimulation plus letrozole and 55 standard ovarian stimulation. Analysis was according to intention-to-treat principle. MAIN RESULTS AND THE ROLE OF CHANCE: No differences among groups were observed in the mean (±SD) number of COCs retrieved: 12.5 (10.4) after ovarian stimulation plus tamoxifen, 14.2 (9.4) after ovarian stimulation plus letrozole and 13.6 (11.6) after standard ovarian stimulation (mean difference -1.13, 95% CI -5.70 to 3.43 for tamoxifen versus standard ovarian stimulation and 0.58, 95% CI -4.03 to 5.20 for letrozole versus standard ovarian stimulation). After adjusting for oral contraception usage at the start of ovarian stimulation, positive ER status and positive lymph nodes, the mean difference was -1.11 (95% CI -5.58 to 3.35) after ovarian stimulation plus tamoxifen versus standard ovarian stimulation and 0.30 (95% CI -4.19 to 4.78) after ovarian stimulation plus letrozole versus standard ovarian stimulation. There were also no differences in the number of oocytes or embryos banked. There was one serious adverse event after standard ovarian stimulation: one woman was admitted to the hospital because of ovarian hyperstimulation syndrome. LIMITATIONS, REASONS FOR CAUTION: The available literature on which we based our hypothesis, power analysis and sample size calculation was scarce and studies were of low quality. Our study did not have sufficient power to perform subgroup analysis on follicular, luteal or random start of ovarian stimulation. WIDER IMPLICATIONS OF THE FINDINGS: Our study showed that adding tamoxifen or letrozole to a standard ovarian stimulation protocol in women with breast cancer does not impact the effectiveness of fertility preservation and paves the way for high-quality long-term follow-up on breast cancer treatment outcomes and women's future pregnancy outcomes. Our study also highlights the need for high-quality studies for all women opting for fertility preservation, as alternative ovarian stimulation protocols have been introduced to clinical practice without proper evidence. STUDY FUNDING/COMPETING INTEREST(S): The study was supported by a grant (2011.WO23.C129) of 'Stichting Pink Ribbon', a breast cancer fundraising charity organization in the Netherlands. M.G., C.B.L. and R.S. declared that the Center for Reproductive Medicine, Amsterdam UMC (location VUMC) has received unconditional research and educational grants from Guerbet, Merck and Ferring, not related to the presented work. C.B.L. declared a speakers fee for Inmed and Yingming. S.C.L. reports grants and non-financial support from Agendia, grants, non-financial support and other from AstraZeneca, grants from Eurocept-pharmaceuticals, grants and non-financial support from Genentech/Roche and Novartis, grants from Pfizer, grants and non-financial support from Tesaro and Immunomedics, other from Cergentis, IBM, Bayer, and Daiichi-Sankyo, outside the submitted work; In addition, S.C.L. has a patent UN23A01/P-EP pending that is unrelated to the present work. J.M.J.S. reported payments and travel grants from Merck and Ferring. C.C.M.B. reports her role as unpaid president of the National guideline committee on Fertility Preservation in women with cancer. K.F. received unrestricted grants from Merck Serono, Good Life and Ferring not related to present work. K.F. declared paid lectures for Ferring. D.S. declared former employment from Merck Sharp & Dohme (MSD). K.F. declared paid lectures for Ferring. D.S. reports grants from MSD, Gedeon Richter and Ferring paid to his institution; consulting fee payments from MSD and Merck Serono paid to his institution; speaker honoraria from MSD, Gedeon Richter, Ferring Pharmaceuticals and Merck Serono paid to his institution. D.S. has also received travel and meeting support from MSD, Gedeon Richter, Ferring Pharmaceuticals and Merck Serono. No payments are related to present work. TRIAL REGISTRATION NUMBER: NTR4108. TRIAL REGISTRATION DATE: 6 August 2013. DATE OF FIRST PATIENT'S ENROLMENT: 30 January 2014.

Human germline nuclear transfer to overcome mitochondrial disease and failed fertilization after ICSI.

PURPOSE: Providing additional insights on the efficacy of human nuclear transfer (NT). Here, and earlier, NT has been applied to minimize transmission risk of mitochondrial DNA (mtDNA) diseases. NT has also been proposed for treating infertility, but it is still unclear which infertility indications would benefit. In this work, we therefore additionally assess the applicability of NT to overcome failed fertilization. METHODS: Patient 1 carries a homoplasmic mtDNA mutation (m.11778G > A). Seventeen metaphase II (MII) oocytes underwent pre-implantation genetic testing (PGT), while five MII oocytes were used for spindle transfer (ST), and one in vitro matured (IVM) metaphase I oocyte underwent early pronuclear transfer (ePNT). Patients 2-3 experienced multiple failed intracytoplasmic sperm injection (ICSI) and ICSI-assisted oocyte activation (AOA) cycles. For these patients, the obtained MII oocytes underwent an additional ICSI-AOA cycle, while the IVM oocytes were subjected to ST. RESULTS: For patient 1, PGT-M confirmed mutation loads close to 100%. All ST-reconstructed oocytes fertilized and cleaved, of which one progressed to the blastocyst stage. The reconstructed ePNT-zygote reached the morula stage. These samples showed an average mtDNA carry-over rate of 2.9% ± 0.8%, confirming the feasibility of NT to reduce mtDNA transmission. For patient 2-3 displaying fertilization failure, ST resulted in, respectively, 4/5 and 6/6 fertilized oocytes, providing evidence, for the first time, that NT can enable successful fertilization in this patient population. CONCLUSION: Our study showcases the repertoire of disorders for which NT can be beneficial, to overcome either mitochondrial disease transmission or failed fertilization after ICSI-AOA.

Impact of stimulation duration and gonadotropin type on the incidence of premature progesterone elevation - a retrospective analysis of the Ensure data.

Elevated progesterone levels on the day of trigger negatively impact the outcome of assisted reproductive technique (ART) treatment and forced ovarian stimulation might be a cause of progesterone elevation during ovarian stimulation. To analyze the impact of forced and prolonged stimulation on the progesterone elevation, this data analysis from the Ensure study compared hormonal stimulation with corifollitropin alpha (CFA)-only with CFA plus recombinant (rec) follicle-stimulating hormone (FSH) after day 8 (CFA-plus group) of ovarian stimulation. In the Ensure study, 268 patients underwent ovarian stimulation with 100 µg CFA and 128 patients with recombinant FSH. A total of 35 patients (13.1%) from the CFA-arm received the hCG trigger after stimulation with CFA-only, 233 patients (86.9%) needed additional rec FSH from day 8 onwards to meet the criteria for trigger. Progesterone levels >0.8 ng/ml on the trigger day occurred in 90 patients (38.6%) from the CFA plus FSH group and only in one patient (2.8%) in the CFA-only group (p < .001). The ongoing pregnancy rate (OPR) was 31.4% (11/35) for patients in the CFA-only group and 24.5% (57/233) for patients CFA-plus group with additional recFSH after day 8 (p = .378). This set of data demonstrates that prolongation of stimulation in combination with intense stimulation leads to a statistically significant increased incidence of progesterone elevation on the day of trigger.

Conventional ovarian stimulation and single embryo transfer for IVF/ICSI. How many oocytes do we need to maximize cumulative live birth rates after utilization of all fresh and frozen embryos?

STUDY QUESTION: What is the impact of ovarian response on cumulative live birth rates (LBR) following utilization of all fresh and frozen embryos in women undergoing their first ovarian stimulation cycle, planned to undergo single embryo transfer (SET). SUMMARY ANSWER: Cumulative LBR significantly increases with the number of oocytes retrieved. WHAT IS KNOWN ALREADY: Several studies have addressed the issue of the optimal number of oocytes retrieved following controlled ovarian stimulation (COS) for IVF/ICSI and demonstrated that ovarian response is independently related to LBR following IVF/ICSI. The vast majority of studies pertained only to the outcome of the fresh IVF cycle and did not evaluate the cumulative LBR following the transfer of all fresh and frozen-thawed embryos after a single ovarian stimulation, which is the most meaningful outcome for the infertile patient. STUDY DESIGN, SIZE, DURATION: This study is a large cohort analysis of retrospective data from January 2009 to December 2013 in a tertiary medical centre, at the Centre for Reproductive Medicine at the University Hospital of Brussels. PARTICIPANTS/MATERIALS, SETTING, METHODS: This study included 1099 eligible consecutive women 18-40 years old undergoing their first IVF cycle and planned to undergo SET in their fresh cycle. All patients were treated with a conventional starting gonadotrophin dose of 150-225 IU recombinant FSH (rFSH) in a fixed GnRH antagonist protocol. Vitrification was used as cryopreservation method. To evaluate the impact of oocyte yield on fresh LBR and on cumulative LBR after utilization of all cryopreserved embryos, patients were categorized into four groups according to the number of oocytes retrieved: 1-3 (Group A), 4-9 (Group B), 10-15 (Group C) or >15 oocytes (Group D). MAIN RESULTS AND THE ROLE OF CHANCE: Regarding LBR in the fresh IVF/ICSI cycles, unadjusted results did not show any significant difference when comparing either high (>15 oocytes) versus normal (10-15 oocytes) (P = 0.65), or normal (10-15) versus suboptimal (4-9 oocytes) responders (P = 0.2). LBR in the fresh cycles were significantly higher (P < 0.05) in high, normal and suboptimal responders when compared with the low ovarian responder group (1-3 oocytes). Moderate-severe ovarian hyperstimulation syndrome occurred in 11 out of 1099 patients (1%). The cumulative LBR significantly increased with the number of oocytes retrieved (χ(2) test for trend P < 0.001). High responders (>15 oocytes) demonstrated a significantly higher LBR not only versus poor (0-3 oocytes) (P < 0.001) and suboptimal (4-9) responders (P < 0.001), but also versus women with normal (10-15) ovarian response (P = 0.014). Finally, although suboptimal responders had a better outcome compared with poor ovarian responders (P = 0.002), this group had a significantly lower cumulative LBR compared with normal ovarian responders (P = 0.02). Multivariate logistic regression analysis showed that the ovarian response category remained an independent predictive factor (P < 0.001) for cumulative LBR. LIMITATIONS, REASONS FOR CAUTION: This is a cohort analysis based on retrospective data collection. Despite our robust methodological approach, the presence of biases related to retrospective design cannot be excluded. High responders may inherently have had a better prognosis. In addition, we cannot provide any guidance for patients undergoing either multiple embryo transfers or treated with higher gonadotrophin doses. WIDER IMPLICATIONS OF THE FINDINGS: Women undergoing COS for their first IVF/ICSI cycle and SET should be informed that, although the number of oocytes retrieved does not affect LBR in the fresh cycle, the higher the oocyte yield, the higher the probability to achieve a live birth after utilization of all cryopreserved embryos. Large cohort studies are needed in order to confirm our results of cumulative LBR in different ovarian stimulation settings with higher stimulation doses. STUDY FUNDING/COMPETING INTERESTS: No external funding was used for this study. No conflicts of interest are declared.

Perceptions of oocyte banking from women intending to circumvent age-related fertility decline.

INTRODUCTION: Women can now opt to bank their oocytes with the intention of increasing their chances of achieving a pregnancy after their fertility has declined. This exploratory study aimed to gain insight into how women, considering oocyte banking to circumvent age-related fertility decline, perceive this intervention. MATERIAL AND METHODS: We conducted a qualitative study in a Dutch university medical center and held in-depth interviews with women on the waiting list for oocyte banking. We recorded the interviews, transcribed them verbatim and used thematic analysis. RESULTS: All women were financially independent and lived in single-person urban households. They opted for oocyte banking because they wished to share parenthood with a future partner rather than becoming a single parent. This strong desire was key in their interpretation of all aspects of the intervention. Women set aside information about the limited success rates and potential risks, as they were optimistic about their own prognosis, thought that the chances for success were equally likely as the chances it would fail, and because of "anticipatory regret". They perceived oocyte banking as a "helping hand" to achieve shared parenthood. Although women found the costs of the intervention high, they were willing to invest their money to increase their chances for shared parenthood. CONCLUSIONS: Oocyte banking allows women to circumvent age-related fertility decline. The prospect of potential shared parenthood overrules the perceived health risks and burden. Health professionals should take this into account when informing potential users of oocyte banking.

Fertility preservation for age-related fertility decline.

Cryopreservation of eggs or ovarian tissue to preserve fertility for patients with cancer has been studied since 1994 with R G Gosden's paper describing restoration of fertility in oophorectomised sheep, and for decades previously by others in smaller mammals. Clinically this approach has shown great success. Many healthy children have been born from eggs cryopreserved with the Kuwayama egg vitrification technique for non-medical (social) indications, but until now very few patients with cancer have achieved pregnancy with cryopreserved eggs. Often, oncologists do not wish to delay cancer treatment while the patient goes through multiple ovarian stimulation cycles to retrieve eggs, and the patient can only start using the oocytes after full recovery from cancer. Ovarian stimulation and egg retrieval is not a barrier for patients without cancer who wish to delay childbearing, which makes oocyte cryopreservation increasingly popular to overcome an age-related decline in fertility. Cryopreservation of ovarian tissue is an option if egg cryopreservation is ruled out. More than 35 babies have been born so far with cryopreserved ovarian tissue in patients with cancer who have had a complete return of hormonal function, and fertility to baseline. Both egg and ovarian tissue cryopreservation might be ready for application to the preservation of fertility not only in patients with cancer but also in countering the increasing incidence of age-related decline in female fertility.

Oocyte banking for anticipated gamete exhaustion (AGE) is a preventive intervention, neither social nor nonmedical.

The scope of female fertility preservation through cryopreservation of oocytes or ovarian cortex has widened from mainly oncological indications to a variety of fertility-threatening conditions. So far, no specific universally accepted denomination name has been given to cryopreservation of oocytes or ovarian cortex for the prevention of age-related fertility decline. We argue that the commonly used phrases 'social' and 'nonmedical freezing' to denote the indication for cryopreservation are not entirely correct. We suggest 'AGE banking', as this has not only the advantage of being catchy but also depicts the exact indication for the strategy, anticipated gamete exhaustion.

Live birth rates in Bologna poor responders treated with ovarian stimulation for IVF/ICSI.

This retrospective study determined the efficacy of ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI) in poor ovarian responders fulfilling the Bologna criteria for poor ovarian response and identified predictors of live birth rates. Overall, 485 patients undergoing 823 ovarian stimulation cycles for IVF/ICSI with maximum gonadotrophin dose (≥ 300 IU) between January 2009 and December 2011 were included. Patients were considered eligible, irrespective of the treatment protocol, if they were classified as poor responders based on the recently developed definition for poor ovarian response by the European Society of Human Reproduction and Embryology, the Bologna criteria. Live birth rates did not significantly differ between women aged <40 and women aged ≥ 40 years either per cycle (7.1 versus 5.2%, OR 1.38, 95% CI 0.77-2.46) or per patient (11.6 versus 8.8%, OR 1.36, 95% CI 0.75-2.46). In logistic regression analysis, the number of oocytes retrieved was the only variable significantly associated with live births (OR 1.92, 95% CI 1.03-3.55 for >3 versus 1-3 oocytes). Bologna poor responders demonstrate very low live birth rates, irrespective of age and treatment protocol used. An increase in the number of oocytes retrieved is an independent variable related to live birth rates.

Pronuclear transfer rescues poor embryo development of in vitro-grown secondary mouse follicles.

STUDY QUESTION: Is pronuclear transfer (PNT) capable of restoring embryo developmental arrest caused by cytoplasmic inferiority of in vitro-grown (IVG) mouse oocytes? SUMMARY ANSWER: PNT to in vivo matured cytoplasm significantly improved embryo development of IVG mouse oocytes, leading to living, fertile offspring. WHAT IS KNOWN ALREADY: In vitro follicle culture has been considered as a fertility preservation option for cancer patients. Studies describing the culture of human follicles remain scarce, owing to low availability of tissue. Mouse models have extensively been used to study and optimize follicle culture. Although important achievements have been accomplished, including the production of healthy offspring in mice, IVG oocytes are of inferior quality when compared to in vivo-grown oocytes, likely because of cytoplasmic incompetence. STUDY DESIGN SIZE DURATION: The study was carried out from September 2020 to February 2022. In total, 120 15-day-old B6D2 mice were used to perform secondary follicle culture and assess the quality of IVG oocytes. In vivo-grown control oocytes were obtained from 85 8- to 12-week-old B6D2 mice, following ovarian stimulation. For sperm collection, four B6D2 males between 10 and 14 weeks old were used. For embryo transfer, 14 8- to 12-week-old CD1 females served as surrogate mothers and 10 CD1 vasectomized males 10-24 weeks old were used to generate pseudo-pregnant females. Finally, for mating, four B6D2 female mice aged 8-10 weeks and two B6D2 male mice aged 10 weeks old were used to confirm the fertility of nuclear transfer (NT)-derived pups. PARTICIPANTS/MATERIALS SETTING METHODS: Secondary follicles from 15-day-old B6D2 mice were isolated from the ovaries and cultured for 9 days, before a maturation stimulus was given. Following 16-18 h of maturation, oocytes were collected and evaluated on maturation rate, oocyte diameter, activation rate, spindle morphology, calcium-releasing ability, and mitochondrial membrane potential. For every experiment, in vivo-grown oocytes were used as a control for comparison. When cytoplasmic immaturity and poor embryo development were confirmed in IVG oocytes, PNT was performed. For this, the pronuclei from IVG oocytes, created following parthenogenetic activation and IVF, were transferred to the cytoplasm of fertilized, in vivo-grown oocytes. Genetic analysis and embryo transfer of the generated embryos were implemented to confirm the safety of the technique. MAIN RESULTS AND THE ROLE OF CHANCE: Following 9 days of follicle culture, 703 oocytes were collected, of which 76% showed maturation to the metaphase II stage. Oocyte diameters were significantly lower in IVG oocytes, measuring 67.4 µm versus 73.1 µm in controls (P < 0.001). Spindle morphology did not differ significantly between IVG and control oocytes, but calcium-releasing ability was compromised in the IVG group. An average calcium release of 1.62 arbitrary units was observed in IVG oocytes, significantly lower than 5.74 in control oocytes (P < 0.001). Finally, mitochondrial membrane potential was inferior in IVG compared to the control group, reaching an average value of 0.95 versus 2.27 (P < 0.001). Developmental potential of IVG oocytes was assessed following parthenogenetic activation with strontium chloride (SrCl2). Only 59.4% of IVG oocytes cleaved to two cells and 36.3% reached the blastocyst stage, significantly lower than 89.5% and 88.2% in control oocytes, respectively (P < 0.001 and 0.001). Both PNT and spindle transfer (ST) were explored in pilot experiments with parthenogenetically activated oocytes, as a means to overcome poor embryo development. After the added value of NT was confirmed, we continued with the generation of biparental embryos by PNT. For this purpose, IVG and control oocytes first underwent IVF. Only 15.5% of IVG oocytes were normally fertilized, in contrast to 45.5% in controls (P < 0.001), with resulting failure of blastocyst formation in the IVG group (0 versus 86.2%, P < 0.001). When the pronuclei of IVG zygotes were transferred to the cytoplasm of control zygotes, the blastocyst rate was restored to 86.9%, a similar level as the control. Genetic analysis of PNT embryos revealed a normal chromosomal profile, to a rate of 80%. Finally, the generation of living, fertile offspring from PNT was possible following embryo transfer to surrogate mothers. LARGE-SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: Genetic profiles of analysed embryos from PNT originate from groups that are too small to draw concrete conclusions, whilst ST, which would be the preferred NT approach, could not be used for the generation of biparental embryos owing to technical limitations. Even though promising, the use of PNT should be considered as experimental. Furthermore, results were acquired in a mouse model, so validation of the technique in human IVG oocytes needs to be performed to evaluate the clinical relevance of the technology. The genetic profiles from IVG oocytes, which would be the ultimate characterization for chromosomal abnormalities, were not analysed owing to limitations in the reliable analysis of single cells. WIDER IMPLICATIONS OF THE FINDINGS: PNT has the ability to overcome the poor cytoplasmic quality of IVG mouse oocytes. Considering the low maturation efficiency of human IVG oocytes and potential detrimental effects following long-term in vitro culture, NT could be applied to rescue embryo development and could lead to an increased availability of good quality embryos for transfer. STUDY FUNDING/COMPETING INTERESTS: A.C. is a holder of FWO (Fonds voor Wetenschappelijk Onderzoek) grants (1S80220N and 1S80222N). B.H. and A.V.S. have been awarded with a special BOF (Bijzonder Onderzoeksfonds), GOA (Geconcerteerde onderzoeksacties) 2018000504 (GOA030-18 BOF) funding. B.H. has been receiving unrestricted educational funding from Ferring Pharmaceuticals (Aalst, Belgium). The authors declare that they have no conflict of interest.

Translation of the Modified Polycystic Ovary Syndrome Questionnaire (mPCOSQ) and the Polycystic Ovary Syndrome Quality of Life Tool (PCOSQOL) in Dutch and Flemish Women with PCOS.

This study aims to determine the test-retest reliability and to confirm the domain structures of the Dutch version of the modified polycystic ovary syndrome questionnaire (mPCOSQ) and the Polycystic Ovary Syndrome Quality of Life Scale (PCOSQOL) in Dutch and Flemish women with Polycystic Ovary Syndrome (PCOS). PCOS patients were contacted with a request to complete both questionnaires (including additional demographic questions) online in their home environment on T0 and on T1. The study was approved by the Ethics Committee of Erasmus Medical Centre and of Ghent University Hospital. In this study, 245 participants were included between January and December 2021. The mPCOSQ has excellent internal consistency (α: 0.95) and a high to excellent Intraclass Correlation Coefficient (ICC) for all six domains (ICC: 0.88-0.96). The PCOSQOL demonstrates excellent internal consistency (α: 0.96) and ICC (ICC: 0.91-0.96) for all four domains. The original six-factor structure of the mPCOSQ is partly confirmed. An extra domain is added to the PCOSQOL which included coping items. Most women have no preference for one of the two questionnaires (55.9%). In conclusion, The Dutch mPCOSQ and PCOSQOL are reliable and disease-specific QoL measures for women with PCOS. Both questionnaires are recommended for clinical practice.

Obstetric outcome in donor oocyte pregnancies: a matched-pair analysis.

BACKGROUND: To investigate the obstetrical and perinatal impact of oocyte donation, a cohort of women who conceived after OD was compared with a matched control group of women who became pregnant through in vitro fertilisation with autologous oocytes (AO). METHODS: A matched-pair analysis has been performed at the Centre for Reproductive Medicine of the UZ Brussel, Dutch speaking Free University of Brussel. A total of 410 pregnancies resulted in birth beyond 20 weeks of gestation occurring over a period of 10 years, including 205 oocyte donation pregnancies and 205 ICSI pregnancies with autologous oocytes (AO). Patients in the OD group were matched on a one-to-one basis with the AO group in terms of age, ethnicity, parity and plurality. Matched groups were compared using paired t-tests for continuous variables and McNemar test for categorical variables. A conditional logistic regression analyses was performed adjusting for paternal age, age of the oocyte donor, number of embryos transferred, and singleton/twin pregnancy. RESULTS: Oocyte donation was associated with an increased risk of pregnancy induced hypertension (PIH) (matched OR: 1.502 CI: 1.024-2.204), and first trimester bleeding (matched OR: 1.493 CI: 1.036-2.15). No differences were observed between the two matched groups with regard to gestational age, mean birth weight and length, head circumference and Apgar scores. CONCLUSIONS: Oocyte donation is associated with an increased risk for PIH and first trimester bleeding independent of the recipients' age, parity and plurality, and independent of the age of the donor or the partner. However, oocyte donation has no impact on the overall perinatal outcome.

Oestradiol valerate pretreatment in GnRH-antagonist cycles: a randomized controlled trial.

This randomized controlled trial analyses the ability to control the oocyte retrieval schedule of gonadotrophin-releasing hormone antagonist cycles through the administration of oestradiol valerate during the luteo-follicular transition period prior to the initiation of ovarian stimulation. Eighty-six women undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection were enrolled in the study. The control group (n = 42) received a standard ovarian stimulation protocol. In the pretreatment group (n = 44), patients were administered oestradiol valerate at a daily dose of 2 · 2 mg from day 25 of the preceding cycle onwards, during 6­10 consecutive days, depending on the day of the week. The primary endpoint was the proportion of patients undergoing oocyte retrieval during a weekend day (i.e. Saturday or Sunday), which was significantly lower in the pretreatment group (1/37, 2.7%) compared with the control group (8/39, 20.5%; P value = 0.029). The clinical pregnancy rates per started cycle were similar in the pretreatment group (38.6%) compared with the control group (38.1%). Pretreatment with oestradiol valerate results in a significantly lower proportion of patients undergoing oocyte retrieval during a weekend day and can be a valuable tool for the organization of an assisted reproduction centre.

Anti-Müllerian hormone for the assessment of ovarian response in GnRH-antagonist-treated oocyte donors.

Evidence regarding the role of anti-Müllerian hormone (AMH) among oocyte donors is limited and only involves gonadotrophin-releasing hormone (GnRH)-agonist-treated donors. This trial assessed the predictive ability of AMH for ovarian response among 108 oocyte donors treated with an antagonist protocol. In multivariate linear regression analysis, both AMH and age were independently associated with ovarian response (unstandardized coefficients 0.904 and -0.378, respectively). In receiver operating characteristic curve analysis, AMH performed better than age, but was a modest predictive marker for low (≤ 6 oocytes) and excessive (>20 oocytes) ovarian response (area under the curve (AUC) 0.643 and 0.695, respectively). Similarly, a multivariate logistic model including AMH and age was also modest (AUC 0.651 and 0.697 for low and excessive responders, respectively). The predictive ability of AMH did not significantly alter when different thresholds were adopted, such as <4 oocytes for low response and >25 for excessive response (AUC 0.759 and 0.724, respectively). Among oocyte donors treated with a GnRH-antagonist protocol, although AMH was correlated with the number of oocytes retrieved, it demonstrates a modest ability in discriminating women with low or excessive ovarian response. Selection of oocyte donors is of paramount importance for the proper and more cost-efficient functionality of the oocyte donation programme. Despite the extensive literature regarding the efficacy of anti-Müllerian hormone (AMH) for predicting ovarian response among infertile patients, available evidence regarding the role of AMH in oocyte donors is considerably limited and involves only agonist down-regulated cycles. In this trial we assessed whether AMH can be considered a predictive marker for ovarian response among oocyte donors treated with a gonadotrophin-releasing hormone (GnRH)-antagonist protocol. According to our results, among oocyte donors treated with a GnRH-antagonist protocol, although AMH was correlated with the number of oocytes retrieved, the correlation is not strong and it appears that AMH has a modest predictive ability to discriminate women who are likely to demonstrate either impaired or excessive response to ovarian stimulation.

Clinical validation of a closed vitrification system in an oocyte-donation programme.

Controversy exists about the risk of microbiological contamination from direct contact with unsterile liquid nitrogen during oocyte vitrification. The aim of this observational study was to evaluate the effectiveness of oocyte vitrification using a high-security closed vitrification system in a donation programme. Oocyte vitrification was performed using CBS High Security closed straws (Cryo Bio System) with DMSO/ethylene glycol/sucrose as the cryoprotectant (Irvine Scientific freeze kit). A total of 123 vitrified metaphase-II oocytes were warmed in 20 recipient cycles (6.2 warmed oocytes per recipient); of these, 111 oocytes (90.2%) survived vitrification and warming. All surviving oocytes were microinjected and 86 (77.5%) were normally fertilized, of which 53 (61.6%) developed up to good-quality day 3. Ten embryo transfers resulted in a clinical pregnancy (50.0%) and an ongoing clinical pregnancy rate of 45%. Five revitrified embryos were warmed in three warming cycles (survival rate 100%). These transfers resulted in an additional ongoing twin pregnancy, leading to a cumulative ongoing pregnancy rate per patient of 50% (10/20). The ongoing implantation rate per warmed oocyte and per injected oocyte was 10.6% (13/123) and 11.7% (13/111). The present data demonstrate that oocyte vitrification using a closed vitrification device yields excellent oocyte survival, fertilization and embryo development.