Donor Sperm Research Articles

O-182 To err is human, also for those working in ART

Abstract Medically assisted reproduction (MAR) centers combine clinical and technical expertise with a very high complexity. Over the years, MAR centers have undergone increased intricacy due to incorporating laboratory techniques, such as cryopreservation of oocytes and embryos and micromanipulation, embryo culture, and pre-implantation genetic testing. Not only the technicality of the MAR laboratory profession is challenging, but the complexity of each phase has increased over the years; the patient population undergoing treatment has expanded, where not only the intended parents’ gametes are involved but also the utilization of gametes from egg and sperm donors, as well as including a gestational carrier receiving the embryo. These complexities have led to the implementation of rigorous control measures to mitigate the risk of errors. Nevertheless, a zero-risk fertility clinic is an illusion, given the many necessary interventions and manipulations in each treatment cycle. Errors in fertility practice involving gametes or embryos can be devastating to patients and clinical personnel, often raising psychological, legal, ethical, economic, and practical concerns. The most critical cases of risk of harm in MAR procedures involve misidentifying a patient, gamete, or embryo, called ‘mix-up,’ which could lead to dramatic consequences. Although the frequency is low, mix-up cases have been described worldwide. Other adverse events derive from preventable human actions, e.g., overlooking an embryo when carrying out assessments, dropping a dish, incorrect labeling, improper pipetting technique, unusually poor thawing, and inadvertent discard of the sample. Human error cannot be eradicated. In the old view, human error was perceived as the root cause of problems, with individuals being viewed as variables requiring control. Conversely, contemporary perspectives consider human error a symptom of deeper systemic issues. As suggested by the Institute of Medicine in 2000, which published the report “To Err Is Human,” the core of the problem lies not with the fallibility of healthcare personnel but the flawed systems within which they operate. Preventing errors is possible by incorporating safety into system processes and hospital structures. Latent errors are errors that arise due to system inefficiencies. In the context of MAR, these latent conditions can, amongst others, be work-related pressure, high workload, lack of communication between team members, distraction, a suboptimal setup of the lab, a lack of clarity in the procedures, and insufficient time for thorough communication. In the famous Reason’s Swiss cheese theory of error, these latent conditions are weaknesses (or gaps/ holes) in the system’s defense layers. When all the holes from each layer (i.e., policy, planning, design, communication) align, they will permit an error to cause harm. Understanding the theory of human errors and building safety into various layers of care processes in MAR are effective ways of reducing errors rather than blaming sentinel individuals. Errors within MAR centers can be prevented by designing the healthcare system at all levels to make it safer, making it hard for people to do the wrong thing and easy for people to do the right thing.

P-508 Management of incidental findings after preconception expanded carrier screening: identifying genetic predispositions to cancer and metabolic conditions in 8010 screened ART patients

Abstract Study question How do individuals and fertility clinics navigate incidental findings from Expanded Carrier Screening (ECS) in reproductive decision-making? Summary answer Incidental ECS findings prompted varied responses from patients and gamete donors, influencing diverse reproductive choices and underscoring the pivotal role of pre-test genetic counseling. What is known already ECS aims to assess reproductive risk in the general population for specific autosomal recessive and X-linked conditions. These manifest in infancy or early childhood and impact life expectancy or the quality of life. ECS results may guide interventions to avoid affected pregnancies, such as the implementation of preimplantation genetic testing of embryos (PGT-M). Additionally, ECS has the potential to uncover incidental findings with significant health implications, such as an elevated cancer risk or diagnosis. However, the lack of comprehensive reporting guidelines necessitates meticulous analysis to ensure effective clinical guidance for these individual findings. Study design, size, duration This retrospective descriptive study assessed the results of ECS tests performed in 5475 patients and 2535 oocyte and semen donors from four different fertility clinics between July 2017 and December 2023. ECS reports with incidental findings in the ATM, FH or LDLR genes were identified and further examined. We calculated individual and reproductive risks for affected individuals and recorded the subsequent clinical management pertaining to each case. Participants/materials, setting, methods Pre-test counselling was offered to both patients and gamete donors before consenting to ECS. Testing was outsourced to an external genetics laboratory using a panel of 309 genes analyzed through next generation sequencing and complementary molecular techniques. The laboratory reported pathogenic and likely pathogenic variants that were subsequently manually reviewed by an internal genetics committee. Personal and reproductive risks were assessed for each case and genetic counseling was provided in a subsequent meeting. Main results and the role of chance Genetic variants in ATM, FH, or LDLR genes were reported in 134 out of 8010 individuals undergoing ECS (1.67%). Among these, 108 variants were identified in patients: 53.7% (n = 58) in ATM, 19.4% in FH (n = 21), and 26.8% (n = 29) in LDLR. Out of the variants identified as incidental findings, 20/108 were actionable and eligible for PGT-M: 19 were associated with an increased risk for breast cancer and 1 for renal cancer. After being informed of the findings and their implications, 7/20 couples opted to revoke treatment as, according to internal policies, PGT-M was mandatory in such cases; 6/20 couples chose to undergo double gamete donation; 6/20 couples opted for PGT-M. Patients with pathogenic variants in LDLR linked to autosomal dominant inheritance for familial hypercholesterolemia (20/108, 18.5%), received follow-up guidelines and family genetic counseling. Pathogenic variants in ATM, FH, and LDLR were also identified in 26 gamete donors (24 oocyte donors and 2 sperm donors). Following internal review, 14 of these variants were considered incidental findings with an increased risk for breast cancer (13/14) or familial hypercholesterolemia (1/14), leading to the exclusion of these potential donors from the donation program. Limitations, reasons for caution The reproductive handling of incidental findings in our population relies on subjective decisions by the internal genetics committee, which may evolve with scientific advancements and recommendations from professional societies. Follow-up data on long-term reproductive outcomes are lacking. Wider implications of the findings This study reveals the diverse reproductive decisions made in response to incidental findings, underscoring the importance of pre-test genetic counseling. Our findings also highlight the subsequent impact on fertility programs, which may lead to the exclusion of gamete donors or patients choosing to revoke treatment. Trial registration number Not Applicable

P-489 Examining information, willingness to donate and beliefs regarding gamete donation among people of reproductive age

Abstract Study question Which beliefs, motives and psychosocial characteristics distinguish people who are willing to donate their gametes from those who are not? Summary answer Willingness to donate does not differ between men and women, but there are differences in beliefs surrounding its risks, motivations and psychological characteristics. What is known already Previous studies have examined the main psychological characteristics of donors and their motivation to donate. Literature shows that donation is motivated by altruism, with donors being autonomous, self-confident, self-acceptant, and goal-orientated people, guided by meaningful values. Gender differences showed that egg donors often have close contact with infertility situations and motherhood and would like to provide this joy to other women. Sperm donors are more motivated by curiosity about their own fertility and want to spread their “good” genes. However, here is still much to know about what distinguish those who are willing to donate from those who are not. Study design, size, duration This is a cross-sectional study. Data was collected through an online questionnaire, which was disseminated using social media. Inclusion criteria were being adult, within a reproductive age range (between 18 and 35 years old), and fluent in Portuguese. Participants/materials, setting, methods A total of 405 participants completed the survey (305 women and 99 men). The questionnaire included sociodemographic data, beliefs towards gamete donation, reasons that might impact the likelihood of donating, and psychological characteristics through self-administered instruments: Experiences in Close Relationships (ECR), Self-Compassion Scale (SELFCS), Self-Report Altruism Scale (SRAS), NEO Five-Factor Inventory (NEO-FFI). Independent t-test was performed to compare men and women and participants willing or not to donate gametes. Main results and the role of chance Women were 22.86 (±.23) years old and men 24.34 (±.43). A total of 24.2% of participants were willing to donate gametes. There were no gender differences regarding willingness. Significantly more women than men believed that donating gametes might imply psychological risks (p=.001). There were gender differences in motivations to donate. Women were more likely to donate if they could receive fertility counselling (p=.005) and information about infertility (p=.037), and if they could talk with other donors (p<.001) than man. Among women, those willing to donate believed donating would not cause psychological damage (p=.004), would be supported by their social network (p =.006) and would not be criticized by family and friends if they did so (p=.011) compared to those not willing. Psychological differences revealed that women willing to donate presented higher levels of common humanity (p=.003), self-kindness (p=.046), were more altruistic (p<.001) and extroverted (p=.027) than those who were not. No differences were found regarding their attachment orientation. Among men, the only differences distinguishing those who considered donating sperm and those who did not was their altruism levels (p=.047). No differences were found regarding their beliefs towards gamete donation, perceived support regarding the decision, attachment style, self-compassion, and personality traits. Limitations, reasons for caution This study included a convenience sample, and participants lacked adequate information about the legal context and implications of donating gametes in Portugal. The sample size of participants considering donating was small, which may affect our conclusion. Wider implications of the findings Women who consider donating seem to present more salient psychological characteristics than men. Stigma and misinformation might prevent women from considering donating eggs. The possibility of receiving fertility counselling and share their experiences with other donors are valued in the process, which should be considered when recruiting donors. Trial registration number NA

O-230 The ethics of disclosing reported conditions in donor-conceived offspring to recipients of the same donor

Abstract Study question To what extent should new genetic risk information, identified after donation, be disclosed to recipients? Summary answer Withholding new genetic risk information from donor sperm recipients may sometimes be ethically justified or even preferred. What is known already In some cases, donor-conceived persons are born with (suspected) harmful genetic mutations. These occurrences may flag increased genetic risks for others if the donor is used for multiple recipients. Genetic conditions can also emerge in donors or their families after donation. Current guidelines, such as those established by the European Directorate for the Quality of Medicines & HealthCare, recommend contacting recipients “in the case of a diagnosis that may seriously affect a child’s health”. However, the specific timing of such disclosures and the circumstances under which (or even whether) information may be withheld are unclear. Study design, size, duration This normative analysis draws initial insights from empirical data obtained from a quantitative study into current practices of fertility clinics and extends to a comprehensive review of academic literature and international guidelines. It evaluates current practices and explores the justifications for (not) informing recipients about (possible) genetic risks linked to their donor, guided by bioethical principles. Participants/materials, setting, methods In June 2023, an electronic questionnaire was sent to all fertility clinics in Belgium to obtain information on current practices regarding the management of genetic mutations in donor treatment. The responses from 15 clinics provided empirical insights that served as an impetus for the subsequent normative analysis. This analysis integrated the findings with normative considerations using the ‘wide reflective equilibrium’ method. Main results and the role of chance Our findings revealed considerable diversity in current practices. Some clinics always informed recipients of newly identified genetic risks (possibly) related to their donor, while others based their decision on various factors. The main arguments for disclosing this information are clinical utility (beneficence) and respect for the recipient’s autonomy. Withholding health-related information can be harmful, especially if it impedes diagnosis and treatment. Moreover, when sperm samples are reserved for additional children from the same donor, disclosure facilitates better-informed reproductive decisions. Conversely, non-disclosure is sometimes justified on the same grounds. If the recurrence risk is absent or equivalent to the general population risk level, disclosure could cause undue alarm and overtreatment. These harms may outweigh the marginal benefits of (immediate) disclosure, particularly for unconfirmed, late-onset, non-severe, and untreatable conditions. Respecting autonomy also implies recognizing the right not to know, by allowing recipients to prespecify the type of information they wish to receive (e.g., untreatable conditions). However, other factors can complicate this assessment. When early diagnosis is crucial, confirming the donor’s link to the reported condition or determining the recurrence risk may take too long. Additionally, a thorough risk analysis becomes more intricate if insemination is planned, embryos are created, or during pregnancy. Limitations, reasons for caution This analysis focuses on cases with anonymous donors and excludes situations involving identifiable and known donors. If the recipient and donor know each other, a distinct set of ethical considerations and duties may emerge. Wider implications of the findings The need for a nuanced, context-sensitive ethical framework for the disclosure of (potential) harmful genetic mutations in a donor to recipients of donor sperm is highlighted. Such a framework could inspire policy development and support ethical decision-making in fertility treatments. Trial registration number Not applicable

O-233 The current landscape for carrier screening in donor conception; a game of chance for donors and recipients?

Abstract Study question How do international regulatory and commercial factors influence donor carrier screening and pose dilemmas for donors, clinics, and recipients. Summary answer Inconsistencies in international carrier screening guidelines and practice for donor conception create a two-tier system for donors and recipients. What is known already Carrier screening is used to identify those who are at risk to have a child with an autosomal recessive or X-linked genetic disorder. Donor banks adopt a commercially viable approach for carrier screening for their market and export, which creates inequalities in donor recruitment and reproductive risk for recipients. For example, UK guidelines require donors to be screened only for cystic fibrosis, with non-European donors screened for conditions known to be more common by ancestry. Real-world pan-ethnic approaches, however, are taken in varying degrees in other countries via extended carrier screening, posing dilemmas for donors, recipients, and clinics. Study design, size, duration Using current available public information, 14 UK, European, and US donor banks were surveyed to understand the screening level for recessive conditions and how this was conveyed to the patient or clinic client. Separately, expanded carrier screening (ECS) results (283 - 502 genes) from 1742 prospective donors from a > 6 year period at a US sperm bank were analysed to calculate acceptance rates if minimal screening and exclusion criteria were applied. Participants/materials, setting, methods UK, European, and US donor gamete banks were identified and surveyed using public information (2023). Separately, internal data from a US sperm bank related to ECS results from 2017 – 2023 was extracted, collated, and evaluated against the UK donor sperm genetic screening guidelines. Main results and the role of chance All donor banks surveyed state donors are genetically screened. For recessive conditions, UK and European banks screened for a small panel of between 3-20 genes, published on a general screening page on the donor bank website, and exclude donors that are carriers. Some offer an additional paid ECS genetic matching service without revealing what the donor or recipient may be carriers for. US banks who perform ECS include these results with a donor profile; some banks exclude carriers of more common recessive disease, while others accept all donors regardless of carrier status. Results from the US sperm bank indicated that of 1742 prospective donors who had ECS, only 117 (6.7%) of carriers would have been reported if screening under minimal guidelines. 665 of the 782 US positive carrier donors would not have been identified as carriers if tested according to UK guidelines. This, together with the observed varying regulation and commercial ECS panels used by donor banks internationally, demonstrate a tiered system of information availability and sharing for reproductive risk knowledge for donors and recipients; recipients are not consistently informed of the limitations of screening of a selected donor, and acceptance of donors to programs is inconsistent. Limitations, reasons for caution The panel composition and number of genes are variable by commercial ECS provider and donor banks may vary their carrier screening policy or commercial ECS options over time. Additionally, other European countries may have differing recommendations in regards to carrier screening practices. Wider implications of the findings As donor sperm imports from within and outside Europe increase, registered donors within countries will present differing genetic risk. Review and implementation of current carrier screening guidelines are required to ensure consistency of methodology and availability of transparent information for donors, recipients, and clinics to consider the wider implications. Trial registration number not applicable

P-371 It’s worth the freeze: outcomes from thawing electively cryopreserved oocytes are comparable in patients with reduced vs normal ovarian reserve at the time of cryopreservation

Abstract Study question For patients coming back to use oocytes derived from elective cryopreservation, does their initial ovarian reserve predict thaw survival, embryos’ developmental milestones and pregnancy success? Summary answer Thaw survival, fertilization rate, embryo development and pregnancy success rates do not vary significantly according to AMH level at initial cryopreservation. What is known already Increasing numbers of patients are electing to cryopreserve oocytes for future use. AMH (Anti Mullerian Hormone) is an ovarian reserve marker often assessed prior to initiation of treatment that predicts response to fertility treatment and the resulting oocyte yield. However, it is not known whether oocytes derived from a patient with compromised ovarian reserve (perhaps over multiple treatment cycles) will fare as well as that of a patient with normal ovarian reserve and a higher per cycle oocyte yield. Our study seeks to shed light on whether a lower initial AMH level negatively impacts the prognosis of the thawed oocytes. Study design, size, duration We included in our retrospective study all oocyte thaw cycles resulting from electively cryopreserved oocytes since 1996 at a single academically affiliated fertility center. 325 patients completed a total of 510 thaw cycles. 315 cycles were excluded from analysis for no AMH information. 6376 oocyte cryopreservation cycles were performed over that timeframe. The primary outcomes were laboratory statistics including oocyte survival, fertilization and embryo blastulation rates, while the secondary outcome was cumulative live birth rates. Participants/materials, setting, methods AMH categories of < 1, 1-2 and > 2 were selected to stratify reduced, low-normal, and normal ovarian reserves, respectively. 70.7% inseminated oocytes with partner sperm while the remaining 29.3% used donor sperm. Mean age at time of oocyte cryopreservation was 36.5 (range 27.5 to 46.2) while mean age at time of oocyte thaw was 39.2 (range 27.7 to 47.5). The statistical analysis was performed using ANOVA for mean comparisons and chi-squared for pregnancy data. Main results and the role of chance Average oocyte yield per cryopreservation cycle was significantly different across AMH groups (7.7 oocytes in AMH < 1, 10.5 oocytes in AMH 1-2, and 17.2 oocytes in AMH > 2, p < 0.01). The number of treatment cycles completed was highest in patients with AMH < 1 at 1.26 cycles. Oocyte survival (mean 89.0%), fertilization rate (mean 75.3%), and blastocyst conversion rate (mean 62.4%) did not vary significantly across AMH groups. Time to oocyte use was not significantly impacted by AMH at the time of initial testing. Those with reduced AMH < 1 came back earlier to utilize the oocytes (787 days), vs 1141 days for patients with AMH 1-2 and 1021 days for patients with AMH > 2. However, this difference was not statistically significant, p = 0.4. The rate of PGT-A euploid embryos did not vary between groups (38.8% in AMH < 1, 45.3% in AMH 1-2, 53.0% in AMH > 2, p = 0.07). Clinical pregnancy, miscarriage rate, and live birth rate in the first transfer cycle was not impacted by AMH. Total cumulative live birth rate was not correlated with AMH (31.6% in AMH < 1, 44.4% in AMH 1-2, 47.8% in AMH > 2, p = 0.48). Limitations, reasons for caution This data was collected at a single fertility center and thus has limited generalizability. 8.0% of patients came back to utilize their oocytes, which varies widely across the published literature. 60.6% of patients did not have AMH assessed as part of their pre-treatment testing and were excluded from analysis. Wider implications of the findings Although reduced ovarian reserve impacts oocyte yield, many studies find no impact on resulting oocyte quality, embryo development and pregnancy success rates. Those with compromised AMH have comparable oocyte thaw outcomes to those with normal ovarian reserve, though more oocyte cryopreservation cycles may be needed to achieve a successful outcome. Trial registration number N/A

Optimizing intrauterine insemination: A systematic review and meta-analysis of the effectiveness and safety of clinical treatment add-ons.

Intrauterine insemination (IUI) is one of the most widespread fertility treatments. However, IUI protocols vary significantly amongst fertility clinics. Various add-on interventions have been proposed to boost success rates. These are mostly chosen arbitrarily or empirically. The aim of this systematic review and meta-analysis is to assess the effectiveness and safety of add-on interventions to the standard IUI protocol and to provide evidence-based recommendations on techniques used to optimize the clinical outcomes of IUI treatment. Systematic review and meta-analyses were performed in accordance with PRISMA guidelines. A computerized literature search was performed from database inception to May 2023. Randomized controlled trials (RCTs) were included reporting on couples/single women undergoing IUI with any protocol for any indication using partner's or donor sperm. A meta-analysis based on random effects was performed for each outcome and add-on. Three authors independently assessed the trials for quality and risk of bias and overall certainty of evidence. Uncertainties were resolved through consensus. Primary outcomes were ongoing pregnancy rate (OPR) or live birth rate (LBR) per cycle/per woman randomized. Registration number PROSPERO: CRD42022300857. Sixty-six RCTs were included in the analysis (16 305 participants across 20 countries). Vaginal progesterone as luteal phase support in stimulated cycles was found to significantly increase LBR/OPR (RR 1.37, 95% CI 1.09-1.72, I2 = 4.9%) (moderate/low certainty of the evidence). Endometrial scratch prior/during stimulated IUI cycles may increase LBR/OPR (RR 1.44, 95% CI 1.03-2.01, I2 = 1.8%), but evidence is very uncertain. Results from two studies suggest that follicular phase ovarian stimulation increases LBR/OPR (RR 1.39, 95% CI 1.00-1.94, I2 = 0%) (low certainty of evidence). No significant difference was seen for the primary outcome for the other studied interventions. The findings of this systematic review and meta-analysis suggest that vaginal luteal phase progesterone support probably improves LBR/OPR in stimulated IUI treatments. In view of moderate/low certainty of the evidence more research is needed for solid conclusions. Further research is also recommended for the use of endometrial scratch and ovarian stimulation. Future studies should report on results according to subfertility background as it is possible that different add-ons could benefit specific patient groups.

P-375 Long-term cryostorage of donor semen does not affect egg donor cycles outcomes

Abstract Study question Does prolonged donor semen cryopreservation impact in success rates of egg donor (ED) IVF cycles? Summary answer Prolonged donor semen cryopreservation does not affect good quality embryos or pregnancy rates in ED-IVF cycles. What is known already Births from cryopreserved semen stored for over 20 years have been documented. In 2004, a case of an IVF birth with semen frozen for 21 years was reported, and in 2005 another case with an IUI birth using semen frozen for 28 years was published. Recently, in 2019, a child born through IVF with semen frozen for over 26 years was reported in UK. In 2019, a study found that prolonged storage of these samples did not affect the outcomes of IVF with own eggs or IUI. Study design, size, duration We analysed data from 969 ED-IVF cycles performed at our centre between 2007 and 2022. Initially, cycles were classified into two independent groups of study to eliminate the impact of differences in embryo culture time. Group 1 or short culture (until Day 3) included 511 cycles from 2007 to 2013, and Group 2 or long culture (until Day5/6) included 458 cycles from 2014 to 2022. Participants/materials, setting, methods Donor oocytes were inseminated by ICSI using donor sperm from our bank. We analysed the relationship between the years of semen cryopreservation and the number of good quality embryos in both groups using Pearson correlation coefficient. Afterwards, the groups were divided into three subgroups based on the years of cryopreservation: 0-<3, ≥3-5, ≥5. Pregnancy and term pregnancy rates were calculated, and their relationship with time of semen cryopreservation were analysed using the Chi-square statistic. Main results and the role of chance No relationship was found between the years of cryopreservation and the number of good quality embryos in either group (Group 1 r=-0.05 and Group 2 r = 0.04). Pregnancy rates for the three subgroups 0-<3, ≥3-5, ≥5 were as follows: 219/454(48.24%),17/ 39(43.59%) and 6/18(33.3%) respectively in Group 1 and 141/213 (66.2%), 62/104 (59.62%), and 85/141 (60.28%) in Group 2. No statistically significant relationship was found in either group (Group 1 p-value=0.41 and Group 2 p-value=0.38). Term pregnancy rates for the three subgroups 0-<3, ≥3-5, ≥5 were as follows: 139/219 (63.47%), 10/17 (58.82%) and 4/6 (66.67%) respectively in Group 1 and 89/141 (63.12%), 39/62 (63.12%) and 56/85 (65.88%) in Group 2. No statistically significant relationship was found in either group (Group 1 p-value=0.91 and Group 2 p-value=0.90). The findings of this study indicate that prolonged donor semen cryopreservation does not appear to have a negative impact on success rates in ED-IVF cycles, both in terms of embryo development, and pregnancy and term pregnancy rates. Limitations, reasons for caution In Group 1 there was a big difference in sample size between subgroups, but it was due to the nature of the study. Wider implications of the findings Despite it seems that prolonged cryopreservation of semen does not affect embryonic viability, there is a lack of many molecular studies to ensure that this does not impact in cellular mechanisms or epigenetics. Trial registration number Not Applicable

P-663 Comparing clinical outcomes in PGT-A cycles using donated oocytes between progesterone and GnRH-antagonist protocols

Abstract Study question Does Progesterone Primed Ovarian Stimulation (PPOS) demonstrate comparable efficiency to the GnRH-antagonist protocol in terms of laboratory/reproductive outcomes in PGT-A cycles with donated oocytes? Summary answer PPOS demonstrates efficiency in PGT-A cycles with donated oocytes, comparable to the GnRH-antagonist protocol, providing cost-effectiveness and enhanced donor comfort. What is known already The demand for TRA cycles with donated oocytes steadily rises each year. This treatment instills high hopes for success. Ongoing advancements in donor stimulation protocols prioritize safety and comfort. The shift from LH agonist to antagonist suppresses LH peaks, and recently, PPOS has joined, offering a more comfortable, cost-effective, and equally safe alternative with fewer ultrasound checks, mitigating ovarian hyperstimulation syndrome. Study design, size, duration Retrospective assessment of an oocyte donor cohort undergoing ovarian stimulation: 182 cycles with the GnRH-antagonist protocol (Group 1: G1) and 120 with PPOS (Group 2: G2), conducted between July 2017 and June 2023. Ovarian stimulation involved 225 IU/d of FSHr or FSHu, triggering with a GnRH agonist, and subsequent biopsy of evolutionarily robust embryos after extended culture. Both fresh and vitrified oocytes, inseminated with either self or donor sperm, were included. Participants/materials, setting, methods We analyzed 1188 embryos (G1: 676; G2: 512). Trophoectoderm biopsies from D5/D6 blastocysts underwent NGS using the Illumina platform (VeriSeq Illumina®, San Diego, CA, USA). Comparison included total and MII oocyte numbers, fertilization rates, viable embryos, euploid/aneuploid embryos, mosaic embryos, and clinical outcomes: biochemical pregnancy (BPR), biochemical pregnancy loss (BPLR), clinical pregnancy (CPR), early pregnancy loss (EPLR), ongoing pregnancy (OPR), and live birth (LBR) rates. Statistical analyses were carried out using R statistical software (v.4.3.1). Main results and the role of chance The mean ages of donors (25.57±4.05) and recipients (41.82±4.06) were comparable in both groups. The male partner’s age differed (G1: 40.47±7.87; G2: 42.34±7.65) (p = 0.019). Results were adjusted for confounding factors, including recipient and donor ages, oocyte and seminal origin, and male factor variables. Ovarian stimulation duration (9.26 days), total gonadotropin dose (2015.64 IU), and oocyte origin (fresh G1: 69.8 %; G2: 62.5 %; vitrified G1: 30.2 %; G2: 37.5 %) showed equivalence. Statistical significance emerged in total oocytes retrieved (G1: 17.92±7.64; G2: 20.23±7.89) (p = 0.008), mean microinjected MII (G1: 10.25±1.79; G2: 10.07±1.36) (p = 0.040) and fertilization rate (G1: 73.98 %; G2: 79.44 %) (p = 0.001). The usable embryo rate was similar (G1: 54.78 %; G2: 54.47 %). Significant differences arose in mean biopsied embryos/cycle (G1: 3.71; G2: 4.27) (p = 0.016), but not for aneuploid embryos (G1: 29.71 %; G2: 29.49 %) (p = 0,998). Biochemical pregnancy rates were significant (G1: 48.8 %, G2: 60.4 %) (p = 0.022). Other clinical parameters showed no differences, with LBR at 35.5 % in G1 and 37.8 % in G2 (p = 0.752). Limitations, reasons for caution The study is retrospective, where we addressed potential biases by incorporating confounding variables. However, to confirm our initial findings, randomized prospective studies with an appropriate sample size are essential. Wider implications of the findings In egg donation cycles, PPOS shows optimal embryonic performance resulting in a live birth rate comparable to the GnRH antagonist protocol. Additionally, it offers cost-effectiveness and enhanced comfort for donors. Trial registration number Not applicable

P-482 Construct validity of the donor conception identity questionnaire and its association with searching for and finding donor connections

Abstract Study question Is there an association between donor conception identity, psychological and social wellbeing, and searching for and finding donor connections? Summary answer Donor conceived individuals differ on key domains that tap into aspects of their donor conception identity. These relate to searching for and finding donor connections. What is known already There is variation in the ways that donor conceived individuals feel about their conception. Factors such as the age of disclosure are associated with how donor conceived individuals feel about being donor conceived. Associations have been found between donor conception identity and parent-child relationship quality among adolescents, suggesting that curiosity and negativity about donor conception are influenced by the valence of the parent-child relationship. The Donor Conception Identity Questionnaire (DCIQ) has not been previously validated. Study design, size, duration 88 donor conceived adults in the UK participated in a cross-sectional study using an online multi-method survey. Data were collected between January and August 2022. The survey was advertised by the Donor Conception Network and Donor Conceived Register Registrants’ Panel via mailing lists and social media and circulated by the research team and others on social media and university mailing lists. The present findings draw from a subsection of the data collected from this survey. Participants/materials, setting, methods Most participants identified as female (n = 65,74%) and were conceived using donor sperm (n = 79,90%). Participants completed the 25-item DCIQ (adapted from studies of donor conception and adoption identity), and the Mental Health Continuum, the Satisfaction with Life Scale, and adapted versions of the community connectedness and pride subscales of the Gender Minority Stress and Resilience Measure and the HIV Stigma Scale. Participants reported on whether they had searched for and/or found donor connections. Main results and the role of chance Factor analysis of items on the DCIQ identified four domains: 1. Concern and centrality, 2. Internalised stigma, 3. Pride and acceptance, and 4. Openness and understanding. ‘Concern and centrality’ correlated positively with community connectedness (r(86)= 283, p=.008), and stigma (r(86)= 280, p= .008), and negatively with pride (r(86) =-.398, p<.001). ‘Internalised stigma’ was positively correlated with stigma (r(86)=.858, p<.001) and negatively correlated with psychological wellbeing (r(85)=-.378, p <.001), satisfaction with life (r(86)= -.263, p=.013) and pride (r(86)=-716, p<.001). ‘Pride and acceptance’ was positively correlated with psychological wellbeing (r(85) = .276, p = .010), satisfaction with life (r(86)=.329, p =.002) and pride (r(86)=.800, p<.001), and negatively correlated with stigma (r(86)=-.396, p <.001). ‘Openness and understanding’ was positively correlated with psychological wellbeing (r(85)=.304, p=.004), satisfaction with life (r(86)=.316, p=.003), and pride (r(86)=.584, p<.001) and negatively correlated with stigma (r(86)=-.614, p<.001). Searchers scored higher than non-searchers on ‘concern and centrality’ F(1, 79) = 7.543, p= .007 and ‘internalised stigma’ (F(1, 79)=4.355, p=.040). Donor conceived individuals who had found donor connections scored lower on ‘internalised stigma’ F(1, 79) = 7.071, p=.009 and higher on ‘openness and understanding’ (F(1, 79)=6.083, p=0.016) compared to those who had not found their donor connections. Limitations, reasons for caution Lack of diversity within the sample with regards to participant gender, age, and donation type means that findings may not apply across donor conceived populations. The sample were self-selected. Causal relationships between variables cannot be established. Wider implications of the findings The DCIQ may be useful to understand variation in donor conceived people’s psychological health and interest in their donor. The value of the measure in a practical context (e.g., in counselling) should now be evaluated. Further work to validate the scale across different contexts and with different populations is recommended. Trial registration number the UK Economic and Social Research Council [New Investigator Award ES/S015426/1

P-487 The experiences and outcomes of donor conceived adults in the UK who are actively searching, open to contact with, and not searching for donor connections

Abstract Study question What are the experiences and outcomes of donor conceived adults who are actively searching, open to contact with, and not searching for donor connections? Summary answer Most participants were actively searching or open to contact, of whom 67% had found or been found by a connection; finding/not finding experiences were complex. What is known already There is variation among donor conceived individuals in their interest in donor connections. Individual reasons for searching for connections, and which donor connections are searched for, also vary. Most research studies have focussed on individuals who are actively searching for their donor or donor siblings. Global increases in direct-to-consumer DNA testing and social media participation mean that connections may be made to individuals unaware of their (or their relatives’) involvement with donor conception. These social and technological changes have also increased the chances of donor conceived individuals being contacted without expecting or desiring contact. Study design, size, duration 88 donor conceived adults in the UK participated in an online multi-method survey between January and August 2022. The survey was designed in consultation with the UK’s largest community networks for donor conception families (Donor Conception Network, DCN) and donor conceived people (Donor Conceived Register Registrants’ Panel, DCRRP). It was piloted by five donor conceived people before launch. Participants were recruited with assistance from DCN and DCRRP, via social media, university mailing lists, and snowballing. Participants/materials, setting, methods Participants were mostly female (n = 65, 74%) and sperm donor conceived (n = 79, 90%). 39 participants (44%) were actively searching for their donor connections, 44 participants (50%) were open to contact but not actively searching, and 5 participants (6%) were not searching. Questions were closed (yes/no, rating scale, or multiple choice) and open-ended, addressing experiences of donor conception, searching for connections, and finding or not finding connections. Data were analysed both quantitatively and qualitatively. Main results and the role of chance Quantitative results showed no differences between groups in how they found out about being donor conceived, and no differences between active searchers and those open to contact in whether they had found their donor connections. 59 participants across all groups (active searchers (n = 29, 74%), open to contact (n = 27, 61%), not open to contact (n = 3, 60%)) had found or been found by a donor connection. Active searchers who had found (Median = 3, IQR = 2) were more likely to feel their expectations had been met compared to active searchers who had not found (Median = 3, IQR = 1). (U = 55.00, p = .003) and those open to contact who had not found (Median = 4, IQR = 2) (U = 110.50, p = .001). Qualitative results showed that participants in all groups mentioned identity and belonging, family relationships, and having found connections as reasons for presently searching/not searching. Experiences of finding/not finding donor connections among participants actively searching or open to contact were captured by the theme complexities, and six subthemes: uncertainties in searching and relating; searching as open-ended; different donor connections, different experiences; expectations and realities; searching as catalysing change; and experiences of other donor conceived people. Limitations, reasons for caution Most participants were members of relevant community organisations. As is common in research in this area, the sample were mostly conceived using donor sperm and identified as female. Donor conceived people who are disinterested in donor connections may be unlikely to participate in research on this topic. Wider implications of the findings Assumptions about individual thoughts and experiences of searching for and connecting with donor connections should not be made based on search activity, nor should this determine access to support services. The nature and impact of the search process itself should be considered when developing appropriate mechanisms of support. Trial registration number Not applicable

P-428 Identifying key factors for achieving biochemical pregnancy in first autologous IVF cycles: an artificial intelligence-assisted approach

Abstract Study question What key factors determine a positive biochemical pregnancy outcome in first autologous IVF cycles, as identified by machine learning (ML) algorithms? Summary answer Maternal age, AMH, BMI, number of day 3 embryos and total embryos transferred emerged as top predictors for biochemical pregnancy across several ML methods. What is known already ML methods are powerful tools that discern patterns from multiple features to predict outcomes. Beyond their clear predictive capabilities, ML algorithms also offer valuable clinical insights by uncovering underlying data trends. These insights come from understanding the algorithms’ decision-making processes, revealing the rationale behind their predictions. While maternal age is known to influence IVF success, other pre-treatment and in-cycle factors also play a significant role. Understanding these factors can enhance patient management and guide clinical advice and interventions. Study design, size, duration This multicenter retrospective study included data from 9,945 cycles performed between January 2010 and July 2021. Only first autologous cycles using fresh oocytes and donor or patient sperm (fresh or frozen) were included. Preimplantation genetic testing (PGT) cycles were excluded. Both pre-treatment and in-cycle variables were considered, with treatment outcome expressed as cumulative biochemical pregnancy. Cases and variables deemed to have poor data quality were excluded. The final dataset comprised 80 variables and 7350 cycles. Participants/materials, setting, methods Five ML classifier algorithms were applied to predict cumulative biochemical pregnancy using pre-treatment and in-cycle variables. The models tested included logistic regression, support vector machine, random forests, gradient boosting and multilayer perceptron. Shapley values analysis was performed to explain the decision-making structures of all the algorithms tested, quantifying the impact of each included feature on outcome prediction. Main results and the role of chance Within our cohort, mean maternal age was 37.3±4.7 years, mean serum AMH was 2.4±2.1 ng/ml, mean BMI was 23.7±4.0 and mean antral follicle count (AFC) was 11.6± 7.6. Notably, 40.1% of cycles used donor sperm, while 33.8% of male patients were normozoospermic. The majority of cycles (90.8%) used antagonist stimulation protocols, yielding an average of 7.8±5.5 oocytes per patient. Fertilization rate was 70.6%, with a mean of 2.7±1.8 usable embryos obtained per cycle. Fresh embryo transfers accounted for 73% of cases, with an average of 1.5±0.9 transfers performed per cycle. The embryo utilization rate was 64.6% and 48.1% of cycles resulted in a biochemical pregnancy. Among the evaluated algorithms, the gradient boosting model demonstrated superior performance, with an accuracy of 70.6±1.4% and AUC of 77.3±1.7%. Shapley values across all five algorithms consistently revealed the negative correlation between maternal age and biochemical pregnancy rates. Among pre-treatment variables, AMH levels had a positive influence on outcomes, followed by BMI, AFC, and parity status. Regarding in-cycle variables, the number of embryos available at day 3 and the total number of embryos transferred, positively affected the chances of pregnancy. The number of mature oocytes was also an important in-cycle predictive feature. Limitations, reasons for caution his retrospective study spans an extended timeframe, suggesting potential variations in clinical and laboratory practices over the years. Therefore, caution is advised in generalizing the results to other patient populations or to contemporary data gathered using newer and enhanced clinical protocols. Wider implications of the findings The consistent identification of maternal age, ovarian reserve markers, and embryo quantity as primary predictors of pregnancy by the five AI models corroborates existing clinical understanding. This consistency emphasizes the strength and dependability of AI to reinforce and complement clinical knowledge with data-driven evidence. Trial registration number not applicable

O-224 “There might be two hundreds of us” - a qualitative study on the experience of meeting large numbers of same donor offspring

Abstract Study question What are the experiences of donor-conceived people who discover large numbers (over 20) of same donor offspring, from a personal and relational point of view? Summary answer Participants reported feeling shocked by the number of donor-siblings. It led them to redefine their identity and their relations with their donor-siblings and the donor. What is known already The experience of discovering and meeting donor-siblings has been recently well documented. Yet, very little is known about how the size of the donor sibling group impacts this experience. A few studies have addressed the need to limit the number of offspring per donor. There is no consensus on what this limit should be and the regulations in that regard vary across countries. Although fears of incestuous relationships are still prevalent, policy discussions tend to focus mainly on the negative psychosocial impacts of discovering a large donor sibling group, however, no empirical evidence has allowed to support this concern. Study design, size, duration We conducted an exploratory study using a qualitative research design. Data collection was conducted in the Fall 2021 and Winter 2022 using a purposive sampling method. No geographical limitations were set for the data collection. Participants/materials, setting, methods The inclusion criteria for the recruitment of participants were: 1) donor-conceived adults aged 18 or over; 2) French or English-speaking; 3) with 20 or more donor-siblings. Data collection was carried out through online in-depth interviews. In total, 22 people took part in the study (16 women, 7 men and 1 non-binary person). They were aged between 21 and 76. Eight came from the US, 7 from the UK, 5 from Canada, and 2 from Germany. Main results and the role of chance The discovery of a large donor-sibling group provoked feelings of shock and surprise, combined with curiosity. Indeed, many participants mentioned that they had been disconcerted by this discovery, which often coincided with the disclosure of their mode of conception. Although the connections formed with their donor-siblings were generally described as enriching, their number was seen as an infringement of their singularity and individuality. The idea of having been “mass conceived” generated a certain unease, sometimes even a feeling of repulsion. Furthermore, the size of the group was often perceived either as a hindrance to the formation of meaningful bonds with donor-siblings, or as a burden. While some regretted not being able to know all their donor-siblings and mourned those impossible ties, others felt overwhelmed by the sheer number of exchanges, obligations, and unpredictable events their number entailed. Finally, a large donor-sibling group was seen by some as a potential obstacle to their relationship with the donor. For some, the fact that the donor donated his sperm on such a large scale questioned his integrity and motivations and depicted him in an unfavourable light. For others, being so numerous competing for his attention minimised their chances of establishing contact with him. Limitations, reasons for caution Despite the innovative nature of the study, the size of the sample and the variability of the experiences do not allow for definitive conclusions to be drawn and limit the understanding that can be gained from it. Further research should examine for example the context of online sperm donation. Wider implications of the findings With the democratization of direct-to-consumer DNA testing, more and more contacts between donor-siblings will occur. It is therefore important to examine how this phenomenon unfolds more specifically in the context of large donor-sibling groups. This will inform policy discussions on the need to limit the number of offspring per donor. Trial registration number Not applicable

P-643 Menopause should not be considered a confounding factor in endometrial preparation protocol’s comparative clinical trials: a retrospective cohort study with 1.109 euploid single embryo transfers

Abstract Study question Does menopause have an impact on obstetric and perinatal outcomes when performing elective euploid single-blastocyst transfers (eeSBT) in a hormonal replacement treatment (HRT) protocol? Summary answer eeSBT in a non-menopause elective HRT group(eHRT) did not show higher success rates nor better obstetric and perinatal outcomes compared to a menopause HRT group(mHRT). What is known already Menopause has been suggested to be a confounding factor in clinical trials when comparing the results and success rates for endometrial preparation in modified natural cycle (mNC) Vs HRT: including menopause patients could lead to selection bias seen that they can never be included in the mNC group. Few data are available on eeSBT ≥3BB (Gardner score) cryotransfers comparing obstetric and perinatal results between eHRT and mHRT, to have the opportunity to include them all in further comparative trials, with a low bias risk. Study design, size, duration Retrospective single-centre comparative study, including 1.109 eeSBT (≥3BB, Gardner score) between Jan-2018 and Dec-2022: 1.025 (92,4%) in eHRT and 84 (7,6%) in mHRT. The eHRT and mHRT groups were homogeneous for egg donor’s age (29,1±5,9 yo Vs 25,8±4,1 yo) recipient’s age (41,4±4,9 yo Vs 44,9±4,7 yo), body mass index (22,6±4,7 Vs 22,6±5,3) severe male factor (3,5% Vs 3,6%), the need for sperm donation (30,0% Vs 35,7%), and the average throphoectoderm embryo quality (A = 32,5% Vs A = 29,8%). Participants/materials, setting, methods We studied the clinical, obstetric and perinatal outcomes of the 1.109 eeSBT, comparing eHRT and mHRT groups for: pregnancy rate, miscarriage rate, live birth rate, twin pregnancy rate, severe preeclampsia, preterm birth rate (<37, <35, <32 and <28 weeks) and neonatal weight. We used Chi-square test and T-Test to compare groups (p < 0,05). Main results and the role of chance There were no statistically significant differences between eHRT and mHRT groups when comparing pregnancy rates (63,7% Vs 64,3%, p = 0,92), miscarriage rates (15,6% Vs 11,1%, p = 0,053) and live birth rates (44,3% Vs 48,8%, p = 0,42); no significant differences were found in the severe preeclampsia rate(2,0 Vs 1,2, p = 0,84), nor in the twin pregnancy rate (0,9 Vs 2,4, p = 0,34) even if it almost tripled in the mHRT group. Preterm, major and extreme preterm birth rates were comprable between eHRT and mHRT groups: <37 weeks (9,9% Vs 4,9%, p = 0,29) < 35 weeks (3,3% Vs 0, p = 0,23) <32 weeks (1,3% Vs 0, p = 0,46) <28 weeks (0,2% Vs 0, p = 0,76). There were no significant differences in neonatal weight (3292 + 481g Vs 3.135 + 419g, p = 0,052). Limitations, reasons for caution In a preliminary study, we compared and additional 245 eeSBT in mNC with the HRT group, and no significant differences in obstetric or perinatal outcomes were reported when including or excluding the mHRT sub-group. Wider implications of the findings In eeSBT, the eHRT group did not report better obstetric nor perinatal results compared to the mHRT group; further prospective clinical trials comparing mNC Vs HRT should not consider menopause as a major confouding factor, when using eeSBT. Trial registration number Not Applicable

P-497 Increasing use of pan-ethnic carrier screening for donor gametes creates new challenges for clinics and recipient counselling

Abstract Study question How can clinics support recipients to understand a positive or negative carrier status following pan-ethnic carrier screening. Summary answer A combination of recipient testing and genetic counselling enables the use of donor sperm irrespective of pan-ethnic screening results. What is known already Data reported by the HFEA, UK reveals that in 2020, more than half of new donor registrations were from donor imports - 48% were American or Danish in origin, where the level of genetic screening for recessive conditions can vary from 3 to 502 genes. Donor banks generally state that donors are screened to professional guidelines for the countries they supply. Variations in the practice for carrier screening of gamete donors and how this information is shared and charged can be opaque to clinics and complex for recipients to navigate without specialist support to understand relevance and reproductive risk. Study design, size, duration This study reports on the number of genetic counselling requests from several IVF clinic referrals in the UK for the period Jan 2020 - Dec 2023. A total of 412 recipients interested in purchasing samples from donors identified as a positive carrier of one or more recessive condition(s) after undergoing extended carrier screening. Referrals for ECS negative donors were not received. Participants/materials, setting, methods Recipients were provided with the opportunity of genetic counselling to include the meaning of the carrier status, risk estimates, and options. Recipients were then given the opportunity to review the consultation report and were supported through their subsequent decision-making. The recipient’s choice to accept the risk for using the donor or proceed to counter-screening was evaluated to give insight into the recipient decision-making for accepting risk or wishing to undertake carrier screening. Main results and the role of chance UK screening recommendations cumulatively account for only 9.3% of identified mutations within a sperm donor applicant population at a single commercial US sperm bank screened using ECS, highlighting international inconsistencies in donor recruitment and acceptance criteria. 15.3 % (n = 63) of recipients elected to be screened for the conditions their donor was a carrier for, with most opting to be screened on a matched gene panel to provide information for a child and allow future matching with an alternative donor. 84.7% (n = 359) proceeded with treatment without counter screening appreciating their relatively low reproductive risk. Patients who undertake consultation with a genetic professional can understand their reproductive risk for autonomous decision-making, indicating ECS positive results are not a barrier to donor gamete selection for treatment. Limitations, reasons for caution ECS panels are variable by commercial provider, donor banks may vary their carrier screening policy or commercial ECS options over time, limiting the findings to the time frame in which the abstract was written Wider implications of the findings Review and implementation of carrier screening guidelines are required to ensure consistency and transparency with access to suitably qualified genetics professionals to provide information counselling and genetic testing options. This allows recipients to maintain a level of autonomy for donor selection and may ultimately widen the available donor pool. Trial registration number not applicable

P-435 Superiority of modified natural cycle vs hormonal replacement therapy in non-menopausal egg recipients of advanced maternal age: clinical outcomes from 1273 single blastocyst transfer cycles

Abstract Study question Is the modified natural cycle (mNC) better than hormonal replacement therapy (HRT) for endometrial preparation in non-menopausal egg recipients of advanced maternal age? Summary answer In women above 40 years, mNC shows better reproductive and obstetrical outcomes compared to hormonal replacement therapy, especially in the subgroup 45-50 years old. What is known already There is extensive evidence showing the superiority of mNC over HRT in terms of live birth rates, miscarriages, and even obstetric complications. Apparently, the presence of the corpus luteum plays a major role in endometrial receptivity and embryo implantation, probably allowing for better placentation. Nevertheless, there is a general belief that the ovulatory cycle of older women is not the best choice for endometrial preparation, although paradoxically they are the group of patients who could benefit most from the reduction of obstetric complications. An increase in cancellation rates for mNC is claimed, without consistent data available. Study design, size, duration Retrospective single-centre comparative clinical study, including 1273 endometrial preparation cycles for frozen single-blastocyst transfer between January 2020 and December 2022: 892 (70,2%) on HRT protocol and 381 (29,8%) on mNC protocol. The two groups were homogeneous for donor’s age (25,7 years HRT vs 25,3 years mNC), recipient’s age (42,2 years HRT vs 42,1 years mNC), severe male factor (6% HRT vs 5% mNC), and the need for a sperm donor (28% HRT vs 26% mNC). Participants/materials, setting, methods Among 1273 started non-menopausal recipient’s cycles, we compared cancellation rates between HRT and mNC due to either medical reasons (inadequate endometrium, bleeding, premature ovulation) or other issues (no embryo survival, COVID-19, etc). We studied the outcomes of the 1096 elective frozen single-blastocyst transfers performed, comparing HRT and mNC cycles for: pregnancy, clinical pregnancy, miscarriage, live birth and <35weeks preterm birth rates. We stratified the results by age and used Chi-square test to compare groups (p < 0,05). Main results and the role of chance The overall cancellation rate was 13.9%. No significant differences in cancellation for medical reasons were found between HRT (7%) and mNC (6.8%), p = 0.93. When we analyse results stratified by age, patients aged 39 or less (270 cycles: HRT 75.9%, mNC 24.1%) showed no statistically significant differences in pregnancy (58% vs 64.6%, p = 0.35), clinical pregnancy (50.7% vs 56.9%, p = 0.34), miscarriage (18.3% vs 18.9%, p = 0.93), and live birth rates (41.5% vs 46.2%, p = 0.5). In the 40-44 age group (494 cycles: HRT 64.2%, mNC 35.8%), no statistically significant differences were found between HRT and mNC in pregnancy (58.2% vs 61.5%, p = 0.47), clinical pregnancy (50.8% vs 51.1%, p = 0.96), and live birth rates (40.4% vs 45.8%, p = 0.25). The HRT group had a significantly higher miscarriage rate (21%) compared to mNC (10%), p = 0.03. For patients aged 45-50 years (332 cycles: HRT 72%, mNC 28%), no statistically significant differences were observed in pregnancy (56.5% vs 62.4%, p = 0.33) and miscarriage rates (24.3% vs 15.1%, p = 0.18). Clinical pregnancy (44.8% Vs 57%, p = 0.04) and live birth rates (33.9% vs 48.4%, p = 0.01) were significantly higher in the mNC group compared to HRT. No significant differences were found between HRT and mNC in preterm birth rates <35 weeks (3.6% vs 4.6%, p = 0.75). Limitations, reasons for caution This study is a single-centre retrospective comparative trial. Our homogeneity study included several confounding variables, however other bias such as severe uterine factor, embryo quality or repeated implantation failure cases were not taken into account. Wider implications of the findings Modified natural cycle should be encouraged as the first option for endometrial preparation in non-menopausal egg recipients of advanced maternal age, having shown superiority over hormonal replacement therapy in patients aged 45-50 years. Moreover, modified natural cycles are more patient friendly and cost-effective, with no increase in the cancellation rates. Trial registration number not applicable

P-782 Are pregnancy complications associated with the method of conception in female same-sex couples? Results of a retrospective, matched cohort study comparing ROPA and IUI

Abstract Study question Are pregnancies in female same-sex couples at a higher risk when using reception of oocytes from partner (ROPA) compared to those following intrauterine insemination (IUI)? Summary answer In female same-sex couples, pregnancies following ROPA demonstrated a higher incidence of preterm birth and first-trimester bleeding. What is known already Reception of Oocytes from PArtner (ROPA) enables both partners to contribute biologically to the desired pregnancy. However, oocyte donation, often performed in case of (premature) ovarian failure, is associated with an increased risk of hypertensive disorders of pregnancy/preeclampsia. Female same-sex couples typically comprising healthy, young women without underlying subfertility problems, are a priori at low absolute risk for pregnancy complications. Few studies have investigated the incidence of pregnancy complications and/or obstetrical outcomes in this specific group of women. Further insights and formal data could guide clinicians and patients in making informed decisions regarding the preferred method of conception. Study design, size, duration A retrospective, single-center, matched cohort study was performed including 577 unique female same-sex couples using donor semen who became pregnant after reproductive treatment (88 pregnancies following ROPA and 489 following IUI). None of the patients who opted for ROPA had (failed) IUI before. The study covered the period from January 2015 to January 2023. Participants/materials, setting, methods Pregnancies following ROPA were matched with pregnancies following IUI for age (+/-4 years), BMI (+/-4 kg/m2), parity (nulliparous vs multiparous) and date of embryo transfer/IUI (+/-1year) in a 1:1 ratio. Statistical Package for Social Sciences (SPSS) v26.0 was used for statistical analysis. Kolmogorov-Smirnov test was used to evaluate the normal distribution of continuous variables. Normally distributed data were analyzed with the student t-test and categorical variables were analyzed with the chi-square test. Main results and the role of chance After matching, 154 pregnancies (77 ROPA versus 77 IUI) were eligible for the study. Age (mean age 31.4±4.0 for ROPA versus 31.2±4.3 years for IUI, p = 0.48) and BMI (24.5±3.9 kg/m2 versus 25.2±4.4 kg/m2, for respectively ROPA versus IUI, p = 0.32) were comparable between groups after matching. Two ROPA pregnancies were excluded from further analysis due to elective termination of pregnancy (radiusaplasia and trisomy 21). Both groups experienced two stillbirths (two unexplained mors in utero, one chorioamnionitis and one intrapartum death). No significant difference in hypertensive disorders of pregnancy (HDP) (10.7% (8/75) versus 13.7% (10/73) for ROPA and IUI respectively, p = 0.53) or preeclampsia rates (11.0% (8/73) and 6.7% (5/75) for ROPA and IUI respectively, p = 0.33) was observed. ROPA-associated preeclampsia cases were often preterm (<37weeks’ gestation) compared to IUI (5/8 versus 1/5). ROPA pregnancies had a higher incidence of preterm birth (15.1% vs 1.3%,p<0.002) and first trimester bleeding was significantly more frequent (12.3% vs 0%,p<0.001). No statistically significant differences were observed between groups in neonatal weight, fetal structural malformations and cesarean section delivery rates. Limitations, reasons for caution The study is limited by its retrospective design and inherent bias. Despite reducing the sample size, matching enhanced study robustness. Recognized risk factors for hypertensive disorder of pregnancy, like the use of donor sperm, may mitigate differences associated with conception methods in this population. Wider implications of the findings The study points out potentially increased obstetrical risks following ROPA. These data are crucial to counsel and guide female same-sex couples in their decision regarding the method of conception. The risk of hypertensive disorders of pregnancy, specifically preterm preeclampsia, associated with ROPA warrants further attention, urging larger prospective studies. Trial registration number not applicable

‘Agency, voice and choice’: reflecting on assisted reproductive technologies through select Indian films

ABSTRACT The article examines the contested aspects of neoliberalism through cinematic narratives, addressing the issue of Assisted Reproductive Technology (ART) in India, a debated subject in socio-legal spheres. Existing literature extensively discusses the biopolitical and bioethical dimensions of commercialization and commodification, particularly concerning organ, egg, sperm donations, and gestational commercial surrogacy. This research endeavors to scrutinise and appraise the ethical quandaries emanating from the technological transformation of motherhood, as portrayed in fictional representations. These narratives shed light on the difficult situations faced by surrogates and egg donors, who are often driven by familial or socio-economic pressures to provide their reproductive services. Consequently, they become commodified within the context of India's In Vitro Fertilization (IVF) industry. Ergo, through the films I Am (2010) and Mimi (2021), this article probes into the intertwining socioeconomic situations of the large percentage of infertile women and claims that the positive discourse around the ‘new Indian women’ is inherently diluted and undermined. Additionally, the research emphasizes that ART—and more importantly, a new agency for single women—is reiterated within the political and socio-historical contexts of the films discussed.

Practical and ethical considerations when sperm donors die.

This paper considers the practical and ethical issues related to the death of a sperm donor. It looks at whether sperm banks should check whether the donor is alive at the time the spermatozoa is made available. Knowing that the donor has died in combination with the cause of death can provide important medical information but the chance is very small. However, when the information is available, it may help to decide whether to tell previous recipients and/or to block the remaining samples for future use. A second advantage may be that the donor's offspring can be informed that contact will not be possible and that recipients who are planning to order spermatozoa from an identity-release donor can be told that the donor has died. However, these advantages presume that identifiable equals contactable while there is no strict link between these two conditions.

Gamete and embryo donation guidance

This document provides the latest recommendations for the evaluation of potential sperm, oocyte, and embryo donors, as well as their recipients, incorporating recent information about optimal screening and testing for sexually transmitted infections, genetic diseases, and psychological assessments. This revised document incorporates recent information from the US Centers for Disease Control and Prevention, the US Food and Drug Administration, and the American Association of Tissue Banks, with which all programs offering gamete and embryo donation services must be thoroughly familiar, and replaces the document titled "Recommendations for gamete and embryo donation: a committee opinion," last published in2013.