Cohort Of Oocytes Research Articles

Is there a relationship between lymphoma aggressiveness indicators and the pattern of ovarian response and oocyte cohort after COH for fertility preservation in AYA lymphoma patients? Results of a cohort study

Is there a relationship between lymphoma aggressiveness indicators and the pattern of ovarian response and oocyte cohort after COH for fertility preservation in AYA lymphoma patients? Results of a cohort study

O-252 Cumulative live birth rates (CLBR) in in vitro fertilization per oocyte used, embryo transferred, and embryo transfer impair with increasing female body mass index (BMI)

Abstract Study question Does the number of oocytes used, embryos transferred, or embryo transfers to achieve specific cumulative live birth rates differ according to female body mass index? Summary answer The greater the female BMI, the higher the number of oocytes, embryos and embryo transfers needed to achieve a liveborn, indicating a lower reproductive potential. What is known already The negative impact of high female BMI on in vitro fertilization (IVF) cycles has been extensively described in the medical literature, although there is no clear agreement on the potential role of oocytes, embryos, and endometrial receptivity on these results. However, the clinical outcome is commonly assessed per embryo transfer in isolated cycles and less frequently in cumulative cycles from the same cohort of oocytes. The number of oocytes or embryos needed to reach specific clinical goals has been never estimated in comparison to women with other BMIs, which gives a relevant multicycle overview of reproductive outcomes. Study design, size, duration This is a multicenter retrospective observational cohort study including a total of 31,289 women undergoing IVF with known BMI and 35,430 embryo transfers performed in 15 IVIRMA centers in Spain, from January 1, 2017, to October 1, 2023 with known outcome. Patients were grouped as Underweight (U, BMI<18.5 kg/m2), Normoweight (N, BMI 18.5-<25 kg/m2), Overweight (Ov, BMI 25-<30 kg/m2), and Obese (Ob, BMI≥30 kg/m2). Participants/materials, setting, methods IVF-ICSI cycles with autologous oocytes and partner’s sperm were analyzed according to female BMI. CLBR per oocyte used, embryos replaced, and embryo transfers in consecutive treatments until reaching live birth or abandon were calculated by survival curve analyses with Kaplan-Meier’s methods estimating hazard ratios (HR), and BMI groups compared by with Log-Rank test. Outcomes per embryo transfer/completed cycle and descriptives were compared by chi square tests, and ANOVA where appropriate. Main results and the role of chance Mean women’s age was 37.6years, 95%CI(37.5-37.6), 36.9 years95%CI(36.7-37.1), 37.7years95%CI(37.6-37.8), and 37.2years95%CI(37.0-37.4) for N, U, Ov, and OB respectively. Mean stimulation days and serum progesterone concentrations the day of hCG administration were comparable. Estradiol on triggering day was statistically higher(p < 0.05) on U group, 2073pg/ml95%CI(2008-2138), compared to the other groups, N 1942pg/ml95%CI(1926-1957), Ov 1840pg/ml95%CI(1808-1872), and Ob 1789pg/ml 95%CI(1742-1835). Number of aspirated oocytes was higher on Ob 9.47,95%CI(9.23-9.71), compared with N 9.1,95%CI(9.02-9.17),p<0.05. LBR per embryo transfer was 35.0%95%CI(32.9-37.3) for U, 33.3%95%CI(32.7-33.9) for N, 32.13%95%CI(30.9-33.4) for Ov ad 28.3%95%CI(26.6-30.1) for Ob, p < 0.001. LBR per completed IVF-ICSI cycle (until reaching live birth or using all embryos) was 41.8%95%CI(69.7-43.9) for U, 40.6%95%CI(40.0-41.18) for N, 39.50%95%CI(38.4-40.6) for Ov, and 39.6%95%CI(37.9-41.37) for Ob, being statistically comparable. Using N as a reference group, HR were 1.07,95%CI(0.98-1.17) for U, 0.98,95%CI(0.93-1.03) for Ov, and 0.90,95%CI(0.84-0.98) for Ob, p-value=0.011, being Ob significantly different compared to N. Regarding HR per embryo transfer, 0.96,95%CI(0.82-1.13) for U, 0.87,95%CI(0.79-0.96) for Ov and 0.76,95%CI(0.66-0.89) for Ob, being statistically different Ov (p = 0.0055) and OB (p < 0.001) from N. With the total number of embryos transferred, HR were better than N in U group, 1.11,95%CI(1.02-1.20), p = 0.0192 and significantly worse in Ov and Ob, 0.91,95%CI(0.87-0.96) and 0.85,95%CI(0.79-0.92), p < 0.001 on both. Limitations, reasons for caution Despite the huge sample of patients included and the statistical approach used, the retrospective design of the study represents its main limitation, thus needing to interpret the findings with caution. Wider implications of the findings IVF-ICSI cycles in women high BMI are less efficient than in normoweight women since a greater number of oocytes, embryos and embryo transfers are needed to reach similar CLBRs. This finding highlights again the advice of initiating IVF with an adequate female body weight. Trial registration number not applicable

P-805 Sperm and embryo genome editing by CRISPR-Cas9 in a mouse model

Abstract Study question We wonder whether it is possible to edit a specific gene in individual mammalian spermatozoa as well as embryo by using CRISPR-Cas9? Summary answer We were able to successfully edit the coat pigment gene on individual spermatozoa as well as embryos by injecting CRISPR-Cas9 during Piezo-ICSI. What is known already Earlier investigations into embryo genome editing with CRISPR-Cas9 were conducted during the S-phase or zygote stage, encountering obstacles such as mosaicism and loss of heterozygosity. To overcome these challenges, performing genome editing at the gamete level is considered more favorable. While it may be achievable in oocytes, sperm genome editing can be ambitious due to the tightly supercoiled DNA around the protamine cores. In initial attempts, simple permeabilization of the sperm membrane allowed CRISPR-Cas9 penetration into the cell; however, the attempts at genomic editing proved to be unsuccessful. Study design, size, duration In the past several months, oocytes were divided into two groups: half of them were used to perform embryo genome editing, whilst the other half was used to edit exclusively the sperm genome through oocyte-mediated sperm decondensation (OMSD), where a single spermatozoon was injected into an enucleated oocyte and used the ooplasmic machinery for DNA decondensation and editing. In both models, CRISPR-Cas9 was used to knock out Tyr gene to create an albino phenotype. Participants/materials, setting, methods B6D2F1 mice were used to retrieve oocytes and spermatozoa. A cohort of oocytes used for the OSMD approach were enucleated, whilst the others were maintained with an intact nucleus. All oocytes, enucleated or not, were injected with a single spermatozoon with Tyr-sgRNA and Cas9 protein. Embryos were cultured until the 8-cell stage and processed for T7E1 cleavage analysis. Genome editing efficiency was calculated following the manufacturer protocol. Main results and the role of chance Of the 40 oocytes used for the study, 20 intact oocytes were used to perform embryo genome editing in the standard fashion, while 20 were enucleated for OMSD experiments. After undergoing Piezo-ICSI with CRISPR-Cas9 solution, 90.0% (18/20) of intact oocytes fertilized. After 48 hours in culture, diploid embryos reached the 8-cell stage at 88.9% (16/18). The 584-bp region of the target site of extracted DNA was amplified and gene modification of the edited diploid embryo cohort was confirmed in 87.5% (14/16). Compared to the OMSD cohort, enucleated oocytes fertilized at 85.0% (17/20) while cleavage rate was lower at 64.7% (11/17) and sperm genome modification at 81.8% (9/11). Both diploid embryos and haploid androgenetic embryos evidence an editing efficiency of 36.8%. Therefore, we verified that genome editing on embryos and sperm achieved the same editing yield. Limitations, reasons for caution While the experimental observations are still limited, it is important to note that these results in the embryo model may be underestimated by the T7E1 cleavage assay that only recognize heterozygous modification. The technique needs further refinement to optimize targeting and editing efficiency. Wider implications of the findings Sperm genome decondensation through an OMSD approach allows CRISPR-Cas9 to edit the sperm genome in order to correct eventual pathogenic mutations present in the gamete. Moreover, these would be the only method to absolutely ensure uniform generation of resulting embryos. Trial registration number not applicable

P-166 An artificial intelligence-powered tool to score fresh donor oocytes and predict blastulation: interim analysis of a prospective investigation conducted at 3 laboratories

Abstract Study question Is the Magenta-score associated with fresh donor oocytes’ blastulation competence, and can it be used to predict blastocyst rates per cohort of inseminated oocytes (BRpC)? Summary answer Developmentally-competent fresh donor oocytes showed significantly higher Magenta-score, although the number of blastocysts obtained was within the predicted range in only 63% of the cycles. What is known already Currently, many couples undergo donor oocyte treatments. However, despite donors being theoretically fertile, not all oocytes are developmentally competent, and many do not reach the blastocyst stage. Even if subjective and ineffective to predict oocyte competence, visual oocyte morphological assessment is still routinely used to evaluate oocytes. Lately, the rise of artificial intelligence (AI) resulted in promising tools to assess oocytes more objectively in a standardized method, possibly providing novel insights into the prediction of their competence. In this context, Magenta-score (Future Fertility), an AI-based image analysis tool, can potentially prove useful to optimize the management of oocyte donation treatments. Study design, size, duration A Blinded cohort study (June-2023/December-2023) was conducted to assess the primary outcome: association between fresh donor-oocytes’ Magenta-Score and their subsequent blastocyst development (assumed to be 50%). A sample size of 779 achieves 80%-power to detect the difference between the null-hypothesis point-biserial-correlation of 0 and the alternative hypothesis of 0.1 using a two-sided test with 5%-significance. Secondary outcomes were differences (i) predicted - true BRpCs, and (ii) predicted - true numbers of blastocysts obtained. Participants/materials, setting, methods Interim-analysis of 514 fresh-oocytes obtained from 63 donors at 3 centers and allocated (7.7±3, range:3-18) to 67 recipients. Pictures of denuded mature oocytes were acquired before ICSI. Magenta-scores were generated blindly (providing only donor age and total number of mature oocytes in cohort to the software). The software also estimated BRpCs and range of blastocysts obtainable from each cohort. Donors’ characteristics, ovarian stimulation/treatment cycle parameters, and sperm analyses were tested as confounders. Main results and the role of chance The only visual oocyte anomaly associated with lower Magenta-score was irregular shape (N = 484,5.4±2.2 vs N = 30,3.3±2.1, Mann-Whitney-U<0.01). Oocytes that developed into blastocysts (N = 194) had significantly higher Magenta-scores versus oocytes that did not reach this milestone (N = 320) (5.8±2.1 vs 4.9±2.3, Mann-Whitney-U<0.01; Odds-Ratio adjusted for sperm motility and incubator [standard/time-lapse]=1.26, 95%CI:1.13-1.34, p < 0.01; power=99.6%). No association was noted with day of blastulation or morphological quality. Data were concordant across centers. The average predicted-BRpC was 39.4±11.4% versus a true-BRpC of 40.6±22.6% (Person’s correlation: -0.24; mean difference: -1.1±27.6%, 95%CI from -7.8% to + 5.6%, p = 0.74). The average predicted number of blastocysts per oocyte cohort was 3.3±1.6 versus a true average of 2.9±1.7 (Person’s correlation: 0.25; mean difference: +0.4±2.0, 95%CI from -0.04 to + 0.9, p = 0.07). In 21% (N = 14) and 31% (N = 21) of cycles, the tool predicted an equal or lower number of blastocysts, respectively. In 5 cycles, no blastocyst was obtained, but the tool did not predict this unexpected outcome. When testing the predicted range of blastocysts obtained, the true number was within the range in 63% (N = 42) of cases and higher than the maximum predicted number in 13% (N = 9) of cases. No confounder was identified on the BRpC in this population of fresh donor cycles. Limitations, reasons for caution Of note, this is an interim analysis of an ongoing study. Not all mature oocytes recovered from a donor were utilized, thus not all oocytes in a cohort were imaged and included in analysis. Other putative confounders on BRpC should be considered in future studies with a larger sample size. Wider implications of the findings Effective management of an oocyte donation program is critical to comply with expected high success rates while minimizing the number of surplus blastocysts produced. The integration of genomic data, recipient couples’ characteristics, and the benefits of objective standardized AI-powered oocyte scoring is the most promising workflow to optimize this task. Trial registration number Not applicable

P-397 A retrospective analysis shows a high effect in reproductive outcomes as age increases associated to endometrial factor in IVF advanced maternal age (AMA) patients

Abstract Study question Is there an increasing risk of a negative reproductive outcomes with every passing year associated with endometrial factor in AMA patients? Summary answer The risk of implantation failure and pregnancy loss associated with endometrial factor increase in 2.0% and 1.2% respectively with each passing year in AMA patients. What is known already Nowadays, there is a delay in maternity due to lifestyle, leading to a progressive increase in the age of women at the first childbirth increasing infertility. However, no universal definition of AMA has been established yet. Typically, studies are performed between different groups of age, establishing arbitrary thresholds. Besides, studies about AMA infertility mainly focus on the decline in oocyte quality, but the effects of age on the endometrium are often overlooked. Therefore, there is a lack of studies centered on endometrial factor and considering age year-by-year to be able to strictly establish when fertility decline starts and its magnitude. Study design, size, duration This retrospective study included a total of 33,735 single embryo transfers from 21,506 IVF AMA patients (>35 y.o, BMI 19-25 kg/m2) performed with high quality embryos (embryos from donated oocytes (donor <35 y.o) or euploid embryos from their own oocyte cohort) transferred in day 5 in an endometrial Hormonal Replacement Therapy (HRT) cycle. Evaluated transfers were performed between 2001 and 2022 in 19 clinics in Spain. This study was approved by an IRB (2203-FIVI-030-PD). Participants/materials, setting, methods A logistic regression analysis was performed, considering the patient’s age (42.93±3.45 y.o.) as a continuous and dependent variable and the reproductive outcome as an independent variable. The risk of obtaining a negative pregnancy outcome was estimated as risk ratios at a 95% confidence interval. A p-value<0.05 was considered as statistically significant. Reproductive rates (live birth and pregnancy loss) were calculated and compared each passing year in the studied range of ages (35-51 y.o). Main results and the role of chance The rates of live birth, Implantation failure and pregnancy loss associated to endometrial factor were affected as age increased in IVF AMA patients (>35 y.o). The implantation failure risk was increased in each passing year a 2% (Risk Ratio (RR) = 1.020 (1.003, 1.021) 95% confidence interval (95%CI), p-value=6.0E-09) and pregnancy loss risk was increased in each passing year a 1.2% (RR = 1.012, (1.003, 1.021) 95%CI, p-value=0.0096). Live birth rate decreased progressively from 42% observed in 35 y.o. to 32% in 50 y.o. Nevertheless, the pregnancy loss rate increased progressively from 29% in 35 y.o. to 37% in 50 y.o. Moreover, results shown a more drastic decrease of implantation failure rate after 42 years old and a pregnancy loss rate after 45 years old. Limitations, reasons for caution Only transfers from Spanish population under a HRT cycle were included, decreasing the results variability. However, the results could not be generalized to other hormonal cycles. Moreover, biochemical and clinical pregnancy loss could not be distinguished in this study considering pregnancy loss as a term that includes both of them. Wider implications of the findings To our knowledge, this is the first study in which the endometrial factor in AMA patients was analyzed year by year, helping to define in a more reliable way the ages at which the sharpest changes occur to improve clinical practices on endometrial implantation failure in AMA patients. Trial registration number Not applicable

P-546 Do patients undergoing PGT-M benefit from the Duostim protocol?

Abstract Study question Do patients undergoing PGT-M benefit from the Duostim protocol? Summary answer PGT-M patients benefit because luteal phase stimulation is as effective as follicular phase stimulation in generating transferable embryos, thereby increasing the chances of treatment success. What is known already Patients undergoing PGT-M often require a larger number of embryos for pregnancy, with 25-50% deemed ineligible for transfer based on the disease indication (recessive, dominant, or sex-linked). DuoStim emerges as a valuable strategy for improving outcomes in poor responders. Progress in blastocyst culture, genetic testing, and vitrification motivates clinicians to optimize ovarian reserve exploitation through tailored stimulation protocols. Luteal Phase Stimulation (LPS) finds success in poor prognosis or oncological cases within DuoStim, a protocol widely used for poor prognosis patients necessitating both Follicular Phase Stimulation (FPS) and LPS. The potential benefits of DuoStim for PGT-M patients remain unexplored. Study design, size, duration Retrospective controlled case-control study conducted with paired FPS- and LPS-derived cohorts of oocytes collected in the same ovarian cycle (DuoStim). The study included 26 patients aged 36.53 ± 4,59 years old, undergoing DuoStim with the indication of PGT-M between July 2022 and October 2023. Participants/materials, setting, methods FPS and LPS were performed using the same daily dose of recombinant gonadotropins in an antagonist protocol. All zygotes underwent blastocyst culture, trophectoderm biopsy, vitrification, and subsequent thawing of one unaffected euploid blastocyst for transfer. The primary outcome was the mean number of transferable blastocysts (not affected euploid ones) obtained per oocyte retrieval from paired FPS- and LPS-derived cohorts. Secondary outcomes included the mean number of oocytes, blastocysts and implantation and pregnancy rates. Main results and the role of chance FPS and LPS were comparable regarding the mean number of mature oocytes collected (7.73 ± 4.27 vs. 7.57 ± 4.56) and the mean number of blastocysts obtained (3.27 ± 2.40 vs. 2.50 ± 1.98). The mean number of transferable blastocysts per retrieval were similar (FPS: 1.21 ± 1.31 vs. LPS: 0.78 ± 0.91). No significant differences in implantation or ongoing pregnancy rates were observed after transfers of euploid single blastocysts derived from FPS or LPS: 70.0% (7/10) vs. 57.14% (4/7). Three patients out of the 26 (11.54%) had transferable embryos only in the luteal phase. Limitations, reasons for caution Our findings warrant additional assessment through studies involving larger sample sizes. While our preliminary data indicate comparable implantation/pregnancy rates for PGT-M blastocysts from both FPS and LPS, further investigation is essential, especially in populations beyond those with a reduced number of usable blastocysts Wider implications of the findings These data underscore that oocytes obtained from LPS are as competent as those derived from FPS. Patients with unaffected euploid embryos solely due to FLS would not have had any transfer without DuoStim. This protocol could be advantageous for women abroad or with time constraints, potentially reducing dropout rates. Trial registration number Not applicable

P-369 DuoStim could be a proper option for women seeking fertility preservation for non-medical reasons

Abstract Study question Is Duostim a suitable option for women who wish to preserve fertility for social reasons? Summary answer Providing the option of DuoStim is an efficient way to expand the cohort of vitrified oocytes in women seeking fertility preservation for non-medical reasons. What is known already A growing number of reproductive-age women are choosing to postpone motherhood, giving rise to the concept of reproductive autonomy. Numerous strategies aim to refine ovarian stimulation protocols. DuoStim, entailing dual ovarian stimulations and retrievals within one menstrual cycle, proves advantageous for those with diminished ovarian reserve or facing cancer. To our knowledge, this is the first study offering DuoStim for social preservation. Study design, size, duration Retrospective controlled case-control study conducted with paired follicular phase stimulation (FPS) and luteal phase stimulation (LPS) derived cohorts of oocytes collected in the same ovarian cycle (DuoStim). The study included 160 patients aged 36.85 ± 3.3 years old, who underwent DuoStim for social egg freezing from October 2018 to September 2023. The primary outcome was the number of MII oocytes retrieved per cycle and secondary outcomes included stimulation duration and gonadotropin dose. Participants/materials, setting, methods FPS and LPS were performed using the same daily dose of recombinant gonadotropins in an antagonist protocol. Oocyte retrieval was performed 36 hours after triggering with gonadotropin-releasing hormone agonist triptorelin acetate (0,2 mg) after the FPS. Luteal phase stimulation protocol began on the 5th day after ovarian puncture using dual trigger, followed by a second oocyte retrieval. Mature oocytes were vitrified 2 hours later following the Kitazato® protocol. Main results and the role of chance Stimulation duration and gonadotropin dose were lower during Follicular Phase Stimulation (FPS) vs. Luteal Phase Stimulation (LPS) (10.8 ± 1.5 days vs. 13.0 ± 2.3, P < 0.05 and 2,487.9 ± 580.8 vs. 3,264.0 ± 942.7, P < 0.05). The number of retrieved oocytes was comparable between the two groups (4.78 ± 3.0 vs. 5.32 ± 3.7; P = 0.15). The mean number of MII oocytes acquired in the LPS group exceeded that in the FPS group (4.16 ± 3.0 vs. 3.58 ± 2.3; P = 0.054), indicating a tendency towards more MII oocytes in the LPS group without achieving statistical significance. A total of 110 patients (69.29%) obtained the same or a greater number of MII during the LPS compared to the FPS. Limitations, reasons for caution Although DuoStim is acknowledged as an option to obtain a greater number of eggs in certain situations, the evidence supporting its utility in social fertility preservation is still limited. It is crucial to recognize the inherent biases in observational retrospective studies. Wider implications of the findings DuoStim could be an advantage for women who live abroad or those who dispose of short periods of time for oocyte vitrification, also potentially reducing the drop-out rate. Trial registration number not applicable

O-003 COC classifier: a new artificial intelligence-based tool for identifying mature oocytes from cumulus- oocyte-complexes

Abstract Study question Can the use of artificial intelligence (AI) enhance the prediction of mature oocytes (MII) from Cumulus-Oocytes-Complexes (COC) significantly surpassing the accuracy of well-trained embryologists? Summary answer The development of a COC classifier, an AI-based tool, improves the prediction of mature oocytes from COCs graded as 3 and 4 before oocyte denudation. What is known already Determining the maturity of Metaphase II oocytes before denudation is a challenge in assisted reproduction due to the presence of a dense cumulus mass surrounding the oocyte and obstructing proper manual scoring, a critical step in intracytoplasmic sperm injection (ICSI) due to risk of granulosa cells removal from immature oocytes. Although there is a certain correlation between COC morphology and nuclear oocyte maturity, it is not 100% accurate. It is reported that approximately 90% of MII oocytes are expected in expanded COCs (grade 1), while in COCs grade 4, more immature oocytes are predicted and only 25% are MII oocytes. Study design, size, duration 931 COC's from 145 patients were submitted to COC grading by both, manual and a new “COC classifier” from October to January 2023. 4 groups were formed according to Ebner criteria, 2008. Grade 1: 192 COC's (suspected mature), fluffy and radiant corona and cumulus; Grade 2: 318 COC's showing fluffy cumulus (suspected mature); Grade 3: 208 COC's with radiant corona (expected mature) and grade 4: 213 COC's (suspected immature) with dense cumulus without visible oocyte. Participants/materials, setting, methods Prospective study included 145 patients (39.3 years ±3.2) from September to December 2023. After COC obtention, excess of granulosa cells, dark and blood cells were removed. 3 hours after egg collection, COCs were photographed and scored manually by 9 well trained embryologists. Before denudation, obtained COCs were classified in 4 morphological stages according to Ebner et al, 2008. Finally, the taken photos from COC's were analysed by the COC classifier, a sypervised deep learning algorithm. Main results and the role of chance After COC's classification as following: Group 1 (suspected mature), fluffy and radiant corona and cumulus with visible oocyte; Group 2, COC's showing dense corona (oocyte clearly visible) but fluffy cumulus (suspected mature); Group 3, COC's with radiant corona (oocyte visible, expected mature); Group 4, COC's (suspected immature) with dense corona and cumulus without visible oocyte. The new software presented an MII oocyte accuracy of 79.16% for group 1, 87.1% for group 2, 83.17% for group 3, and 73.23% for group 4. In comparison, manual COCs grading by nine experienced embryologists yielded accuracy rates of 73.5% MII oocytes in group 1, 79.5% for group 2, 50.3% for group 3, and 46.9% for group 4. Statistical analysis, using the chi-square test, was performed to compare the accuracy rates between the COC classifier and manual grading. The results revealed significant differences in favor of the COC classifier when compared to manual method for the groups 3 and 4 (p < 0.001). These results indicate a superior performance of the COC classifier in predicting MII oocytes for groups with highest rates of inmture oocytes. However, for groups 1 and 2, there were no statistically significant differences between the COC classifier and manual grading. Limitations, reasons for caution Further validation through a large-scale, prospective, randomized study is necessary to confirm the efficacy and reliability of the new COC classifier, particularly in patients with oocyte cohorts enriched with grade 3 and 4 COCs. Ongoing research is currently being conducted in our laboratory. Wider implications of the findings The new COC classifier, an AI-based tool, developed by our group, offers a non-invasive and efficient method in predicting mature oocytes before denudation by identifying more MII oocytes from patients’ cohorts enriched with grade 3 and 4 COC's, postponing denudation and injection timing or destinating them to conventional IVF Trial registration number 5678765

P-764 A decade of transformations in IVF strategies towards enhanced clinical efficacy, efficiency, and safety: the real-life experience of 6610 couples

Abstract Study question To what extent do clinical and laboratory strategies affect the main measures of IVF success? Summary answer Across 10 years, the implementation and increasing adoption of antagonist protocols combined with agonist-trigger, freeze-all, blastocyst culture, PGT, and multicycle counseling approach improved IVF outcomes. What is known already The primary indicator of IVF success is the cumulative-live-birth-rate per intention-to-treat (CLBR per ITT). Since reproductive competence is inherent to every gamete and embryo, IVF treatments cannot guarantee success. However, they can maximize the likelihood of success with the safest approaches available. Furthermore, there are other outcomes to consider for a more thorough assessment of IVF effectiveness and efficiency, including time in treatment (=LB achieved / no LB achieved and no embryo available for transfer; TiT), miscarriage rate, and prevalence of multiple-births. Moreover, a family planning perspective should be strengthened in IVF aiming at ≥ 2 healthy children, whenever feasible. Study design, size, duration Longitudinal observation of 6610 couples undergoing ≤6 ovarian-stimulations (OS) for IVF at a private clinic within 3 years. Couples were clustered in 11 groups according to the year of their first treatment (years: 2010-2020) and compared for (i) CLBR within 3 years, (ii) prevalence of ≥ 1 miscarriage and ≥1 twin-delivery, (iii) TiT (from first-OS to the last IVF procedure before treatment conclusion), (iv) prevalence of ≥ 2 singleton-deliveries within 6 years. Participants/materials, setting, methods The naïve patients included increased from ≈500 in 2010 to ≥ 600 between 2013 and 2020. The maternal age was stable around 38±4 years with ≈20% prevalence of severe male factor. OS was conducted through long, short flare-up, mild, antagonist, progestin-primed, or DuoStim protocols with hCG/agonist-trigger. All patients underwent ICSI on fresh own eggs and cleavage/blastocyst culture, fresh transfer/freeze-all, untested/euploid transfers, single/multiple-embryo transfers. Main results and the role of chance Antagonist-protocols (≈20% in 2010 and ≈80% in 2020) combined with agonist-trigger (0.4% and 76.8%) superseded long/short flare-up (≈60% and <10%) and hCG-trigger (99.6% and 23.2%). DuoStim, introduced in 2015, reached 15%-prevalence by 2020. The MII-oocytes collected at first-retrievals increased from 5±3 (2010) to 7.2±4.9 (2020). The prevalence of first-cycles without embryos raised from 3% to 14% by 2020 primarily due to an evident cleavage-to-blastocyst culture switch (2010:96% versus 4%; 2020:1% versus 99%). Similarly, PGT-A and freeze-all utilization respectively increased from 3% to 80% and from 12% to 93%. Although TiT increased from ≈2 cycles in ≈140 days (2010-2013) to ≈1.6 in ≈160 days (2014-2020), the 3-years CLBR improved from 32% (2010) to 42% (2020), a difference confirmed also adjusting for maternal age and overall number of MII-oocytes collected (multivariate-OR:1.03,95%CI:1.01-1.05;adjusted-p=0.001). This was paralleled by the halving of women suffering ≥1 miscarriage (≈12% to < 6%;p=0.002) and drop in women with ≥1 twin-delivery (7.5% to 0.5%;p<0.001). The latter achievement was due to single-embryo transfer rates increasing from 26% (2010) to 98% (2020). Accordingly, the women starting in 2017 and obtaining ≥2 LBs within 6-years were 9.9%, 98% of which after consecutive singleton-deliveries; these figures were 6.6% and just 22% among women starting in 2010(p = 0.004). Limitations, reasons for caution This study suffers from the inherent limitations of a retrospective design. Temporal changes, other than clinical strategies and laboratory advancements (e.g., personnel), might have influenced the results, although no critical infrastructural changes were implemented. Gestational and neonatal follow-up data are missing in this study. Wider implications of the findings Clinical and laboratory advancements enhanced IVF efficacy and efficiency over time also fulfilling family planning desire. Future strategies and improved workflows should focus on reducing drop-out and time-to-LB. As larger oocyte cohorts led to higher CLBR throughout maternal age, tailored-multicycle approach might represent a valuable option to this end. Trial registration number none

Children born after assisted reproduction more commonly carry a mitochondrial genotype associating with low birthweight

Children conceived through assisted reproductive technologies (ART) have an elevated risk of lower birthweight, yet the underlying cause remains unclear. Our study explores mitochondrial DNA (mtDNA) variants as contributors to birthweight differences by impacting mitochondrial function during prenatal development. We deep-sequenced the mtDNA of 451 ART and spontaneously conceived (SC) individuals, 157 mother-child pairs and 113 individual oocytes from either natural menstrual cycles or after ovarian stimulation (OS) and find that ART individuals carried a different mtDNA genotype than SC individuals, with more de novo non-synonymous variants. These variants, along with rRNA variants, correlate with lower birthweight percentiles, independent of conception mode. Their higher occurrence in ART individuals stems from de novo mutagenesis associated with maternal aging and OS-induced oocyte cohort size. Future research will establish the long-term health consequences of these changes and how these findings will impact the clinical practice and patient counselling in the future.

Could the presence and proportion of three/multiple pronuclei (3PN/MPN) zygotes indicate the cytoplasmic maturation state of oocyte cohort in conventional IVF patients?

Although abnormally fertilized zygotes with three or multiple pronuclei (3 PN/MPN) are commonly believed to be associated with improper maturation of the oocyte cytoplasm in conventional IVF cycles, no studies investigated the association between the proportion of MPN zygotes and the maturation state of the oocyte cohort. We compared the cytoplasmic maturity of oocytes from conventional IVF cycles with different proportions of 3 PN/MPN zygotes. A total of 1428 conventional IVF patients with ≥6 oocytes retrieved and fresh embryos transferred were divided into 4 groups according to the proportions of 3 PN/MPN zygotes. The pregnancy outcomes and the proportion of nuclear immature oocytes were analyzed to suggest the cytoplasmic maturation state of the oocyte cohort. Our results showed that the group with a low proportion of 3 PN/MPN zygotes had a higher clinical pregnancy rate (CPR) than those without 3 PN/MPN zygotes (P < 0.05). However, the live birth rate (LBR) was not significantly different between the two groups. The implantation rate (IR), CPR, and LBR did not differ between the low-proportion and high-proportion 3 PN/MPN groups. The proportion of nuclear immature oocytes on day 1 was highest in the group without 3 PN/MPN zygotes (23.8 %) and gradually decreased with an increased proportion of 3 PN/MPN zygotes (P < 0.001). Therefore, the presence of 3 PN/MPN zygotes after conventional IVF may indicate a more mature cytoplasmic state of the oocyte cohort, and the increased proportion of 3 PN/MPN zygotes is associated with an increased maturation state of the whole oocyte cohort. The occurrence and proportion of 3 PN/MPN zygotes may serve as an indicator for the cytoplasmic maturity of the oocyte cohort and help clinicians evaluate the efficiency of ovarian stimulation and optimize the stimulation protocols in subsequent cycles.

Improved fertilization, degeneration, and embryo quality rates with PIEZO–intracytoplasmic sperm injection compared with conventional intracytoplasmic sperm injection: a sibling oocyte split multicenter trial

To investigate whether PIEZO-intracytoplasmic sperm injection (PIEZO-ICSI) increases the fertilization rate, decreases the degeneration rate, and increases the utilization rate per oocyte injected compared with conventional intracytoplasmic sperm injection (ICSI). Sibling oocyte split multicenter trial. Fertility clinics. Women with a diagnosis of infertility who used ICSI as their method of insemination and had ≥6 mature oocytes for injection. Participants had their mature oocyte cohort divided, where half were injected using conventional ICSI and the other half were injected using PIEZO-ICSI. For patients with an uneven oocyte number, the extra oocyte was injected using conventional ICSI. The injection technique used first was also randomized to ensure that there was no bias due to order of injection. The primary outcome measure was the fertilization rate after injection. A total of 108 patients underwent a sibling split use of conventional ICSI and PIEZO-ICSI. The fertilization rate was 71.6% in PIEZO-ICSI, which significantly increased compared with that in conventional ICSI 65.6%. In addition, the oocyte degeneration rate decreased in PIEZO-ICSI compared with that in conventional ICSI (6.3% vs. 12.1% respectively), and the blastocyst quality increased, as measured by the number of grade A and B quality blastocysts present on day 5 of development (33.3% vs. 27.5%). No significant differences in the aneuploidy or utilization rate, clinical pregnancy, or live birth outcome after single embryo transfer were noted between the two injection techniques. This trial supports the possibility that PIEZO-ICSI increases the fertilization rates, decreases the oocyte degeneration rates, and increases the blastocyst quality compared with conventional ICSI; however, it does not appear to influence the clinical pregnancy or live birth rate per transfer. Australian and New Zealand Clinical Trial Registry ACTRN12620000407998.

Detecting partial premature ovulation during follicular aspiration compromises the quantity, but not the quality, of the oocytes retrieved in stimulated in vitro fertilization (IVF) cycles.

To analyze if partial premature ovulation (PPO) detection during oocyte pick-up (OPU) impairs the quality of the retrieved oocyte cohort. The PPO concept refers to the situation when premature ovulation happens only in some of the follicles and it is detected during OPU. This study constitutes a retrospective analysis performed in an infertility clinic (Spain) during 2016-2021 with patients undergoing OPU after controlled ovarian hyperstimulation for an in vitro fertilization (IVF) treatment. Study code: 2110-VLC-091- VG, registered on December 9 2021. Data from women with PPO (n=111) were compared to a matched control sample of cycles without PPO (n=333) at a proportion of 1:3. Cycles were matched for age, body mass index (BMI), treatment year, embryo genetic analysis and stimulation protocol type. The mean numbers of oocytes (6.1 vs. 11.2), mature oocytes (4.7 vs. 8.8), correctly fertilized oocytes (3.6 vs. 6.6) and top-quality blastocysts (0.9 vs. 1.8) were significantly lower in the PPO group than the nonPPO group (p<0.05). However, maturation, fertilization, top-quality blastocyst and pregnancy rates were statistically comparable among groups (p>0.05). Cycles with PPO have fewer available oocytes and, thus, fewer available embryos for transfer, al though their quality is intact, and still offer chances of pregnancy in these cases. Hence cycle cancellation may not be worth associated money, time and morale losses once PPO is detected.

Oocyte competence is comparable between progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) and GnRH-antagonist protocols: A matched case-control study in PGT-A cycles

ObjectiveTo outline oocyte competence after progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) compared to conventional GnRH-antagonist protocol. Study designRetrospective matched case-control study involving advanced-maternal-age women undergoing ICSI with PGT-A. 89 NETA-PPOS were matched with 178 control patients based on maternal age and ovarian reserve biomarkers. Both groups underwent recombinant-FSH OS with GnRH-agonist ovulation trigger and collected ≥1 MII. In the study group, NETA (10 mg/day) was administered orally starting from day2 of the menstrual cycle. Euploid blastocyst rate per cohort of metaphase-II oocytes (EBR per MII) was the primary outcome. All other embryological and clinical outcomes were reported. Gestational age, birthweight and length were also assessed. ResultsThe EBR per MII was comparable among PPOS and control (13.9 % ± 19.3 % versus 13.3 % ± 17.9 %; the sample size allowed to exclude up to a 10 % difference). Blastocysts morphology and developmental rate were similar. No difference was reported for all clinical outcomes among the 61 and 107 vitrified-warmed euploid single blastocyst transfers respectively conducted. The cumulative live birth delivery rate per concluded cycles was also comparable (24.7 % versus 21.9 %). Neonatal outcomes were analogous. ConclusionsOocyte competence after NETA-PPOS and standard OS is comparable. This evidence is reassuring and, because of its lower cost and possibly higher patients’ compliance, supports PPOS administration whenever the patients are indicated to freeze-all (e.g., fertility preservation, PGT-A, oocyte donation). More data are required about follicle recruitment, oocyte yield, gestational and perinatal outcomes. Randomized-controlled-trials are advisable to confirm our evidence.

Human-induced pluripotent stem cell-derived ovarian support cell co-culture improves oocyte maturation in vitro after abbreviated gonadotropin stimulation.

Human-induced pluripotent stem cell-derived ovarian support cell co-culture improves oocyte maturation in vitro after abbreviated gonadotropin stimulation.

Reproductive characteristics and gametogenic cycle of the scleractinian coral Dendrophyllia ramea.

The present study marks a pioneering investigation into the reproductive cycle of the scleractinian coral Dendrophyllia ramea. This is one of the first reproduction studies conducted in the Mediterranean Sea for a colonial azooxanthellate coral. Coral samples were collected in 2017 (May and October) and 2018 (February and July) in the Alborán Sea (SW Mediterranean). This location was selected due to its rarity as one of the few sites where this species thrives at depths shallower than 40 m. These samples were used to study the sexual patterns, fertilization mechanisms and gametogenic cycles by means of histological techniques. To broaden the scope, Sea Surface Temperature (SST) and Chlorophyll-a (Chl-a) data from open access databases have been considered to explore the potential influence of these environmental factors as triggers for gamete development and spawning time. The findings cast D. ramea as a gonochoric species, since no hermaphroditic specimens were observed among the analysed samples. Additionally, the lack of larvae and embryos in any of the analysed polyps, suggest that this species is fertilised externally. Two oocyte cohorts have been detected simultaneously, hinting at a yearly reproductive cycle, characterised by a prolonged oocyte maturation and seasonal spawning period taking place between August and October. Nevertheless, D. ramea display a low fecundity compared to other scleractinians inhabiting deep waters. Lastly, the early stages of gametogenesis seem to be coupled with the highest Chl-a values (i.e., March and December), whereas spawning takes place throughout the warmest period of the year (August to October).

O-178 Conventional IVF results in better embryo development when compared with ICSI in patients without severe male factor

Abstract Study question Which fertilisation technique offers better embryo development results in patients without severe male factor? Summary answer Conventional IVF offers better results regarding embryo development than ICSI in patients without male factor when applying both techniques in the same cohort of oocytes. What is known already ICSI was originally indicated for severe male factor. Nevertheless, it is currently used for many other indications so that it has become the most used technique. One of the reasons for the use of ICSI is the fear of a fertilisation failure when using conventional IVF (cIVF). We have to consider that ICSI is more expensive and invasive. For this reason, it is important to know whether there is a justification to use it in these cases. Study design, size, duration It is a randomized prospective study where 68 IVF/ICSI cycles were analysed. The study comprised 812 oocytes and 469 embryos and was conducted from January to December 2022 in the Assisted Reproduction Unit of a tertiary hospital. In each cycle, we performed a mixed technique using cIVF and ICSI in the same cohort of oocytes. MII rate, fertilisation rate and embryo development were analysed. Participants/materials, setting, methods All consecutive cycles with at least 6 fresh oocytes and semen parameters suitable for cIVF were offered to participate. In each cycle, oocytes were divided into two groups in order of collection and the fertilisation technique (cIVF or ICSI) was randomly assigned for each group. All the embryos were cultured to blastocyst stage. Data of maturity, fertilisation and embryo development were individually registered for every oocyte. Data were statistically analysed by applying multilevel regression models. Main results and the role of chance The patients average age was 36.3±3.0 (28 to 40) and the number of oocytes per cycle was 11.9±5.1 (6 to 26). 396 oocytes (48.8%) were allocated to cIVF group and 416 (51.2%) to ICSI group. The percentage of mature oocytes was significantly higher in cIVF group than in ICSI group (88.9% vs 81.5%, p = 0.017), which is consistent with the later assessment of maturity in cIVF. There were no statistically significant differences between cIVF and ICSI groups in terms of fertilisation rate (59.6% vs 56.0%) and high-quality blastocyst rate (A+B) (9.3% vs 8.7%) when analysed per oocyte. We observed clinical but not statistical differences in blastocyst rate per oocyte (30.6% cIVF vs 23.6% ICSI, p = 0.09). However, blastocyst rate per fertilised oocyte showed statistically significant differences (51.3% cIVF vs 41.6% ICSI, p = 0.047). Additionally, we found statistically significant differences between cIVF and ICSI in the rate of usable blastocysts (transferred or cryopreserved) per oocyte (26.3% vs 18.3%, p &amp;lt; 0.01) and per fertilised oocyte (44.1% vs 32.2%, p &amp;lt; 0.01). In 57.8% of the cycles, the best blastocyst was obtained by cIVF and in 42.2% by ICSI. Fertilisation failure was observed in 3 patients with cIVF and 1 patient with ICSI. All of them had ≤4 mature eggs. Limitations, reasons for caution This study includes the 68 patients who met the recruitment requirements until this moment. It is a part of a wider work, which will analyse a higher number of oocytes and pregnancy and perinatal outcomes. For this reason, the sample size is a limitation to the interpretation of the results. Wider implications of the findings Our findings encourage the use of cIVF when there is no severe male factor. Considering that cIVF is cheaper and less invasive than ICSI, the exclusive use of ICSI in these patients does not seem to be justified according to our results. Trial registration number not applicable

P-268 Artificial intelligence (AI) image analysis outperforms patient age as a surrogate marker for oocyte quality, demonstrating an increased accuracy in predicting blastocyst development

Abstract Study question Can an AI image analysis tool (VIOLET) provide better predictions of oocyte potential than the current standard, patient age, as it relates to blastocyst development? Summary answer While increasing patient age slightly correlates with decreases in blastocyst development, VIOLET provides personalized assessments of individual oocytes correlated to blastocyst development with improved accuracy. What is known already Increasing patient age correlates to decreases in oocyte competency, leading to greater challenges in successful fertility treatment. Clinically, patient age is used to estimate probabilities of success based on national databases. Such as the case in oocyte cryopreservation cycles, considering only age and number of mature oocytes vitrified. However, oocyte quality may vary widely between patients of the same age, and even within each cohort of oocytes. VIOLET is an AI tool that assesses images of mature denuded oocytes to provide an analysis shown to significantly correlate with subsequent blastocyst development and quality, consistently outperforming embryologists in this task. Study design, size, duration This large-scale retrospective study assessed 9,120 mature denuded oocytes retrieved during 2014-2022, representing 1,384 patients between ages 19-49, attending 7 fertility clinics across 5 countries. The VIOLET prediction model is based on image analysis of mature denuded oocytes, without incorporating clinical variables, such as age. Patient age was used to build a separate predictive model of blastocyst development (10,947 training and 3,750 validation samples) to assess the predictive value of age in comparison to VIOLET. Participants/materials, setting, methods Blastocyst development was determined by embryos achieving a Gardner grade by Day5/6 post-ICSI. Blastocyst rates per oocyte cohort were calculated by number of blastocysts divided by total number of mature oocytes retrieved. Various machine learning techniques were trialed to build the predictive model strictly using age; with Random Forest model providing the best-balanced performance. VIOLET and the age model assessed the images and age of 9,120 mature denuded oocytes, respectively, providing predictions of blastocyst development. Main results and the role of chance Blastocyst development was significantly different between patients &amp;lt;35 years old compared to those ≥35 years old [47% vs 42%; p &amp;lt; 0.05 by Two Proportion Z-test]; however, not when the older age group was stratified further. On a patient level, the cohort of oocytes was evaluated by the blastocyst development ratio. Among four age groups (&amp;lt;35, 35-37, 37-40, &amp;gt;40), the blastocyst development ratios per cohort were very similar, with overlapping distributions of 84-94% using Kernel Density estimates. Thus, patient age group does not provide enough information to explain blastocyst development success for an individual oocyte or within an oocyte cohort. In comparison, VIOLET probability is significantly correlated to blastocyst development (p &amp;lt; 0.05; Welch’s Two sample t-test). And blastocyst development rates display a stepwise positive correlation that is significantly different between VIOLET probability quartiles [24% vs 39% vs 47% vs 53%; p &amp;lt; 0.05 by Two Proportion Z-test], providing meaningful information on individual oocytes. Additionally, the predictive model built with age as the only feature had poor ability to predict blastocyst success of an individual oocyte with a limited area-under-the-curve (AUC) of 0.5—unable to separate positive and negative classes. This was outperformed by VIOLET, which displayed an AUC of 0.62 on the same unseen dataset. Limitations, reasons for caution Increasing maternal age causes increased chromosomal abnormalities in oocytes, which translates to lower efficacy with treatment outcomes; therefore, further research to assess VIOLET correlation with PGT-A and implantation outcomes is needed and underway. Wider implications of the findings Patient age correlates with blastocyst development on a general level; however, it does not provide meaningful insights to distinguish rates of blastocyst success on an individual oocyte or oocyte cohort level. VIOLET augments oocyte understanding over the current standard of care, which can be utilized to support personalized clinical decision-making. Trial registration number Not applicable.

O-223 Sperm Genome Editing by CRISPR-Cas9 through an Ooplasm-Mediated Approach

Abstract Study question Can we edit the sperm genome by CRISPR-Cas9 through an ooplasmic-mediated approach? Summary answer The ooplasm-mediated technique induced the decondensation of the male gamete nucleus and allowed CRISPR-Cas9 to access the sperm DNA to carry out successful edits. What is known already Previous studies on genome editing using CRISPR-Cas9 have been performed at the S-phase or zygote stage, but challenges were represented by mosaicism and possible off-target edits. To address these issues, gene editing at the gamete level would be ideal. While this may be feasible in oocytes, it appears ambitious in the spermatozoon due to the DNA hypercoiling around the protamine core and the chromatin compaction. In preliminary experiments, permeabilization of sperm membrane allowed penetration of CRISPR-Cas9 to enter the cell, however, genomic editing was proved unsuccessful. Study design, size, duration In the past 5 months, a total of 128 oocytes were divided into 2 groups. To edit exclusively the male genome through oocyte-mediated sperm decondensation (OMSD), a single spermatozoon was injected into an enucleated oocyte to produce a haploid androgenetic embryo. The control cohort consisted of embryos generated through standard ICSI with the established heritable genome editing (HGE) approach. Both groups were treated with CRISPR-Cas9 aiming to knockout Tyr gene to create an albino phenotype. Participants/materials, setting, methods B6D2F1 mice were used to retrieve oocytes and spermatozoa. A cohort of oocytes used for OSMD approach were enucleated. While the intact oocytes were used for HGE control. All oocytes were injected with a single spermatozoon together with CRISPR-Cas9 solution, containing Tyr gRNA. All embryos were cultured up to the 8-cell stage. Individual blastomeres were isolated and sequenced to proof editing. DNA was extracted and amplified for T7E1 analysis to validate genome editing efficiency. Main results and the role of chance Of the 128 oocytes used for the study, 51 were enucleated for the OMSD experiments, while 77 were used for HGE control. After undergoing ICSI with CRISPR-Cas9 solution, 84.3% (43/51) of the OMSD cohort displayed a single male pronucleus and 79.2% (61/77) control HGE fertilized. In a time-lapse microscopy, 95.3% (41/43) of the OMSD experimental group developed to the 2-cell stage, comparable to the HGE control development at 96.7% (59/61). After 48 hours in culture, the HGE control reached 8-cell development at 88.5% (54/61), while the OMSD cohort cleaved at the lower rate at 60.4% (26/43, P&amp;lt;0.001). A 423-bp region around the CRISPR target site was amplified on DNA extracted by isolated blastomere. Gene modification at the target site was confirmed in 33.7% (70/208) of OMSD cohort and 29.7% (88/296) of the HGE control embryos. Limitations, reasons for caution While the experimental observations are still limited, it is important to note that these results may be underestimated since embryos with completely uniform modifications may go undetected by T7E1 assay. The technique needs further refinement to optimize targeting efficiency and support embryo development. Wider implications of the findings Once the genetic editing method is optimized, individual pseudo-blastomeres generated through this OMSD approach can be utilized as male gametes to fertilize oocyte. The generation of live offspring with the corrected haplotype will serve to prove the safety of genome editing through this technique. Trial registration number N/A

P-285 Analysis, including morphokinetic data, of IVF/ICSI cycles with oocytes containing aggregates of smooth endoplasmic reticulum (SER)

Abstract Study question Is there a difference in ART outcomes and morphokinetic parameters for SER+ and SER- cycles and oocytes? Summary answer Fertilisation and blastulation rates are lower in the SER+ group but no difference was seen in pregnancy or live birth rates. What is known already The SER is an organelle found in eukaryotic cells, including oocytes. SERs synthesize lipids and steroids, and store and metabolise calcium ions, needed for fertilization and early embryonic development. SERs can aggregate in the oocyte, forming an intracytoplasmic dimorphism, thought to interfere with reproductive outcomes. It is suggested that SER aggregates in an oocyte may negatively effect embryo development and implantation. Oocytes without SERs, but which arise from the same oocyte cohort as SER+ oocytes may also affect outcomes. Evidence around the safety and use of these SER+ and SER- oocytes is conflicting, with widespread variations in clinical practice. Study design, size, duration A retrospective review was conducted of all IVF/ICSI[MW1] cycles between January 2019 and December 2020 at Merrion Fertility Clinic, Dublin. Cycles containing SER+ oocytes were identified, and their outcomes were compared with those of a matched control group of SER- cycles. Within the SER+ group, results were compared for SER+ and SER- oocytes within the same cohort. Participants/materials, setting, methods Once participants had been identified, a chart review was undertaken noting demographics, IVF protocol used, duration of stimulation, ART and neonatal outcomes and morphokinetic parameters in the embryoscope. Statistical analysis was performed using PRISM. Main results and the role of chance There were 77 SER+ cycles with a total of 135 SER+ oocytes and 645 SER- oocytes, accounting for 8% of total cycles for the study period. These were matched to 64 control cycles with 528 SER- oocytes. 12 embryo transfers occured using blastocysts derived from SER+ oocytes. SER+ cycles had a higher mean oocyte number than controls (9.3 vs 7.3) and 92% of oocytes were mature compared to 88% of the control group. Fertilisation rates were significantly lower in the study group (60% SER+cycle; 68% in SER-cycle), related to the SER+ oocytes in that cohort. Good/top quality blastocyst rates differed (SER+ cycle 28%, SER- cycle 36%) but pregnancy(SER+ cycle 53%, SER- cycle 51%) and livebirth (SER+31%, SER- 32% ) rates were similar, even when blastocysts derived from SER+ oocytes were transferred. 5 morphokinetic variables were studied – time to 2-cell (t2), 3 cell (t3) 4 cell (t4), 5 cell (t5) and time to blastulation (tB). T5 appears to be shorter in embryos derived from SER+ oocytes than in controls, with the other parameters being comparable. In terms of neonatal outcomes there were no congenital malformations reported in the SER+ groups and one case of upper limb amelia in the control group. Limitations, reasons for caution This study is limited by its retrospective nature. We only have embryoscope data on 46 out of 77 patients with SERs, limiting numbers. Embryos transferred which derived from SER+ve oocytes were limited by the clinic policy to only transfer these embryos if no other embryos available. PGT was not performed. Wider implications of the findings This preliminary study shows that, while SER+ cycles have lower fertilisation rates than SER- cycles, pregnancy rates and live birth rates are comparable. Neonatal outcomes are reassuring. Initial analysis of morphokinetic data shows little effect. Larger numbers and further analysis are needed to fully understand the importance of these aggregates. Trial registration number n/a