Euploid Embryo Rate Research Articles

O-157 The effect of growth hormone on the euploid rate and morphokinetic signature of blastocysts in patients with advanced maternal age : a randomized controlled trial

Abstract Study question Does growth hormone (GH) supplementation during ovarian stimulation affect the euploid rate and morphokinetic characteristics of euploid embryos in patients with advanced maternal age (AMA)? Summary answer GH supplementation improved the probability of obtaining euploid blastocysts in women with AMA, while did not affect the morphokinetic parameters of the euploid embryos. What is known already Studies have demonstrated that supplementation with GH during ovarian stimulation (OS) has positive impact on the clinical outcomes of in vitro fertilization (IVF). However, few studies have investigated the association of GH supplementation with the ploidy status of embryos. Meanwhile, it is unclear whether GH supplementation affects the morphokinetic signatures and the transfer outcomes of euploid blastocysts. Therefore, the underlying reason for the effect of GH on IVF outcomes remains largely unknown. Study design, size, duration This is a single centre open-labelled randomized controlled trial conducted at single IVF center from August 2022 to August 2023. A total of 441 patients were screened for eligibility and 309 patients were enrolled and allocated. The primary outcome was the proportion of cycles which obtained euploid blastocysts. Secondary outcomes included euploid blastocyst rate per cohort, euploid blastocyst rate per cycle and morphokinetic parameters of euploid embryos obtained with or without GH supplementation. Participants/materials, setting, methods A total of 309 patients aged 38–46 years who underwent their first preimplantation genetic testing for aneuploidy (PGT-A) cycle using antagonist protocol were randomized into the GH group or the control group at 1:1 ratio, with all embryos cultured in the time-lapse monitoring system. Patients in the GH group received 2 IU/day subcutaneous GH from the 2nd day of the previous menstrual period until the day of trigger, for a total of approximately 6 weeks. Main results and the role of chance The baseline and cycle characteristics between the two groups were similar. The proportion of cycles which obtained euploid blastocysts was significantly higher in the GH group (44.74% vs 31.85%, p = 0.02). The GH group had a significantly higher euploid blastocyst rate per cohort (38.46% vs 28.01%, p = 0.01) and mean euploid blastocyst rate per cycle (per biopsy cycle 0.38±0.43 vs. 0.26±0.39, p = 0.02; per OS cycle 0.29±0.41 vs. 0.19±0.36, p = 0.03). Multivariate logistic regression indicated GH supplement was an independent factor for acquisition of euploid embryos (adjusted risk ratio=1.79, 95%CI [1.06-2.99], p = 0.03). We did not observe a statistically significant difference in the morphokinetic parameters and transfer outcomes of the euploid embryos acquired with or without GH supplemented. Limitations, reasons for caution This was a single center study which limited the sample size, further limiting the number of patients with euploid blastocysts analyzed for the morphokinetic parameters and transfer outcomes. Meanwhile, affordability may also introduce selection bias since patients were required to pay for GH. Wider implications of the findings Our research presents new evidence that GH supplementation AMA patients increased the probability of obtaining euploid blastocysts, and explains the underlying reason for the positive effect of GH on IVF outcomes in existing studies. The effect of GH on morphokinetic parameters and transfer outcomes of euploid embryos warrants further investigation. Trial registration number NCT05447208, www.clinicaltrials.gov.

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

P-507 Prediction of clinical efficacy of PGT-A based on maternal age and embryo quality in patients with recurrent implantation failure (RIF) or recurrent pregnancy loss (RPL)

Abstract Study question Can the utility of PGT-A be predicted by selecting embryos based on both maternal age and embryo quality in patients with RIF or RPL? Summary answer The predictive value of PGT-A can potentially be determined by assessing maternal age and embryo quality of experiencing patients with RIF or RPL. What is known already Embryo quality and euploid status are crucial determinants in selecting embryos for euploid embryo transfer to achieve a successful pregnancy. This is because embryos with high morphological scores may still exhibit aneuploidy, making morphologic evaluation alone limited. This limitation is particularly important in patients with a history of RIF and RPL. Aneuploidies occur during meiosis in the embryo and increase significantly with age, becoming a major contributor to implantation failure, leading to unsuccessful pregnancies, miscarriages, and congenital birth defects. Study design, size, duration This retrospective study, conducted at a single center, assessed embryo quality in 927 blastocysts derived from 221 cases of patients with RIF and 863 blastocysts derived from 204 cases of patients with RPL. The study spanned from January 2022 to November 2023. Blastocysts were scored using the KIDScore provided by the Embryoscope® time-lapse system (Vitrolife, Göteborg, Sweden) following the manufacturer’s protocols and subsequently underwent next-generation sequencing (NGS)-based PGT-A. Participants/materials, setting, methods A total of 927 RIF and 863 RPL patients’ blastocysts were analyzed, resulting in 256 and 242 euploid embryos, respectively, using NGS. Euploid embryos were classified by morphokinetics (good quality and medium quality) and maternal age groups (≤35, 36-37, 38-39, 40-41, 42-43, 44-45, ≥46). In RIF, 62.9% (161/256) of euploid embryos were classified as good quality, and 37.1% as medium quality. In RPL, 59.1% (143/242) were classified as good quality, and 40.9% as medium quality. Main results and the role of chance The euploid embryo rate decreases in both good- and medium-quality embryos as the patient’s age increases. For RIF patients: ≤35 (47.1% and 22.7%), 36-37 (46.7% and 19.8%), 38-39 (37.5% and 16.4%), 40-41 (37.5% and 11.5%), 42-43 (31.8% and 10.0%), 44-45 (0% and 11.1%), ≥46 (0% and 0%). For RPL patients: ≤35 (46.0% and 25.4%), 36-37 (45.9% and 25.0%), 38-39 (43.8% and 15.1%), 40-41 (27.9% and 18.0%), 42-43 (26.3% and 11.7%), 44-45 (0% and 12.5), ≥46 (0% and 0%). Moreover, ongoing pregnancy or live birth rates also decrease as the patient’s age increases, while the miscarriage rate increases. For RIF patients: ≤35 (57.8% and 16.1%), 36-37 (50.0% and 18.8%), 38-39 (46.2% and 25.0%), 40-41 (43.5% and 28.6%), 42-43 (36.4% and 33.3%), 44-45 (0% and 100%). For RPL patients: ≤35 (59.5% and 12.0%), 36-37 (52.0% and 18.8%), 38-39 (47.8% and 31.3%), 40-41 (43.5% and 37.5%), 42-43 (40.0% and 42.9%), 44-45 (0% and 100%). However, embryo transfer was not possible for those over 46 due to all embryos being aneuploidy. Therefore, PGT-A is valuable for patients under 42, proves beneficial for reducing the abortion rate, and achieving a high pregnancy rate for those aged 42-43, and should be considered for patients over 44. Limitations, reasons for caution This data is from a retrospective study, and well-designed prospective studies with data from multiple centers, larger samples, and extended study periods are needed to validate the current results. Additionally, obtaining information on demographic characteristics, detailed embryo information, and overall clinical outcomes can further enhance the current results. Wider implications of the findings These findings suggest that individualizing each case based on both maternal age and embryo quality is helpful in predicting the utility of PGT-A. Such personalized considerations can result in significant benefits for patients by optimizing outcomes, reducing cycle times, and consequently lowering related costs. Trial registration number not applicable

Preimplantation genetic testing for complex chromosomal rearrangements: clinical outcomes and potential risk factors.

Complex chromosome rearrangements (CCR) are rare structural abnormalities involving at least three breakpoints, categorized into three types based on their structure: type A (three-way rearrangements), type B (double two-way translocations), and type C (exceptional CCR). However, thus far, limited data exists on preimplantation genetic testing for chromosomal structural rearrangements (PGT-SR) in CCR carriers. This study aims to evaluate the clinical outcomes and influencing factors of PGT-SR in couples with CCR. Fifteen couples with unique CCR recruited from 793 couples following PGT-SR between January 2017 and May 2023. In addition, a total of 54 CCR cases, 39 previously reported as well as 15 newly added, were included in the analysis of factors associate with normal/balanced embryos. A total of 100 blastocysts were biopsied and analyzed in 15 CCR couples after 17 PGT-SR cycles, with 16.0% being euploid, 78.0% aneuploid and 6.0% mosaic. 11 normal/balanced embryos and one mosaic embryo were transferred, resulting in eight live births. Furthermore, based on the combined data from 54 CCR carriers, the proportion of normal/balanced embryos was 10.8%, with a significant decrease observed among female carriers compared to male heterozygotes (6.5% vs. 15.5%, p = 0.002). Type B exhibited the lowest rate of euploid embryos at only 6.7%, followed by type A at 11.6% and type C at 14.0%, although the differences were not significant (p = 0.182). After completing the multivariate generalized estimating equation (GEE) analysis, type B (p = 0.014) and female carrier (p = 0.002) were identified as independent risk factors for fewer euploid embryos. The occurrence of balanced CCR in patients with reproductive abnormalities may be more frequent than we expected. Despite the proportion of normal/balanced embryos being significantly low, which can be influenced by CCR type and carrier's sex, PGT-SR may improve the reproductive outcomes among CCR cases. These findings can optimize the clinical management and genetic counseling of CCR carriers seeking assisted reproductive technology (ART).

#89 : Higher Euploidy Rate in Embryos Generated by ICSI Using Sperm Obtained After Microfluidics Sperm Sorting (MFSS). A Randomised Controlled Trial

Background and Aims: MFSS is a state-of-the-art technology that has the ability to sort a subpopulation of sperm cells with lower DNA fragmentation index (DFI), higher motility and higher normal forms without the need for centrifugation. Methods: A randomised controlled trial that included 925 couples that were planned for ICSI with day 5/6 biopsy, PGT-A with Next Generation Sequencing (NGS) and blastocyst vitrification. The embryo transfer was planned for future cycles. The inclusion criteria for women were age (18–45), BMI (18–30), AMH level more than 1.1 ng/ml, regular menstrual cycle and normal uterine ultrasound. Whereas the inclusion criteria for men were age (18–50), fresh semen sample with count more than 10 million/ml and total motility more than 30%. Semen samples were randomly assigned with 1:1 ratio to either preparation by routine density gradient (DG) or (MFSS). The primary outcome of the study is PGT-A aneuploidy results. The secondary outcome is the fertilisation rate, and blastocyst development rate. Results: The study was performed between January 2020 and July 2021. 463 semen samples were prepared with density gradient and 462 semen samples were sorted with microfluidic sperm sorting. All of the prepared semen samples were used for ICSI. The euploid embryo rate for the embryos resulted from density gradient preparation was 53.1% versus 59.3% for the embryos resulted from microfluidics sperm sorting (p=0.0034). The fertilisation rate was 77.9% for density gradient group versus 78.3% microfluidics group (p=0.063) and blastocyst rate was 51.6% for the density gradient group versus 59.2% for the microfluidics group (p=0.058). Conclusion: Semen samples prepared with MFSS for ICSI generated higher euploidy embryos following PGT-A with NGS.

P-703 The role of maternal polymorphic karyotype variants among embryonic ploidy and mosaicism status in patients undergoing IVF treatments

Abstract Study question Is there a relationship between the chromosomal status of biopsied embryos and the presence of polymorphic variants in the female karyotype in IVF cycles? Summary answer The chromosomal status of biopsied embryos is prejudiced because of the presence of specific maternal polymorphic variants (qh-, qh+ and ps+) or combinations of them. What is known already Due to the increasing average age of patients who undergo IVF cycles with their own oocytes, more cycles are performed with embryo biopsy for preimplantation genetic test of aneuploidies (PGT-A). Thus, advanced maternal age has been defined as the main factor causing embryonic chromosomal abnormalities. However, few studies have established direct relationships with other factors. The prevalence of chromosomal polymorphic variants has a higher incidence in the infertile population, which is why there is a need to know the role they play in the genetic inheritance of embryos. Study design, size, duration Retrospective evaluation of a cohort of women who underwent autologous IVF cycles and karyotyping. The sample included 162 IVF cycles with embryo biopsy on D5 and/or D6 for PGT-A, performed between July 2017-December 2021: control group (CG) with normal karyotype (86) and study group (SG) with presence of polymorphisms (76). We studied the connection between maternal karyotype polymorphisms and molecular genetic outcomes in terms of euploid, mosaic, and aneuploid blastocyst rates. Participants/materials, setting, methods The analysis of the karyotype of women, prior to the IVF cycle, was performed using the guidelines of the International System for Human Cytogenetic Nomenclature (ISCN). The trophoectoderm biopsies on D5 and/or D6 blastocysts were analysed by NGS using the Illumina platform (VeriSeq Illumina®, San Diego, CA, USA). The association between the different polymorphic variants in the female karyotype and chromosomal status of embryos was analysed using R (v. 4.2.0) statistical software. Main results and the role of chance We analyzed the results of 483 embryos from 162 IVF-PGT-A cycles. Mean female age was 39.05±2.72 (CG) and 38.97±2.90 (SG). Mean number of mature oocytes (MII) was 7.16±3.94 (CG) and 8.01±5.33 (SG). Mean number of biopsied embryos was 2.97±2.15 (CG) and 2.93±1.88 (SG). No statistically significant differences were found between the CG and SG groups in terms of the rate of euploid embryos: 26.99% vs 21.50% (p = 0.3), transferable mosaic embryos: 8.90% vs 6.76% (p = 0.5), aneuploid embryos: 61.98% vs 69.96% (p = 0.12) and non-informative embryos: 2.13% vs 1.78% (p = 0.2), respectively. However, an increase in the rate of chromosomally abnormal embryos was observed when analysing each polymorphism individually. In females carrying the qh+ variant, we found a statistically significant decrease in the euploid embryo rate: 10.97% vs 26.00% found in CG (p = 0.036). Moreover, the variants qh+ and ps+ increased the rate of aneuploid embryos: 84.17% vs 63.48% in CG (p = 0.013) and 73.52% vs 61.30% in CG (p = 0.021), respectively. Furthermore, it is found that the qh- variant increased the rate of transferable mosaic embryos: 20.00% vs 8.90% in CG (p = 0.025). The results were corrected for confounding variables such as maternal age, oocyte origin and male factor variables, including polymorphic variants in the male karyotype. Limitations, reasons for caution Presence of unmeasured variables that may influence the results. Larger prospective studies including homogeneous cohorts are needed in order to corroborate our initial results. Wider implications of the findings The results show that polymorphic variants in the female karyotype may have a direct effect on the embryonic ploidy and mosaicism status. Therefore, it would be advisable for patients who undergo IVF-PGT-A cycles to have a karyotype performed and be informed of the implications that it may entail. Trial registration number Not applicable

P-176 Is there a relationship between ovarian reserve, oocyte and embryo quality in patients undergoing PGT-A?

Abstract Study question Is there a relationship between ovarian reserve, oocyte and embryo quality in patients undergoing PGT-A? Summary answer Our data revealed no relationship between percentage of aneuploid blastocysts in patients with hormonal signs of reduced ovarian reserve. What is known already Poor ovarian reserve, as determined by serum anti-mullerian hormone (AMH) and antral follicle count (AFC) levels, is a known risk factor for poor outcomes in in vitro fertilization (IVF). Ultrasound imaging is considered to be the most reliable method for measuring ovarian reserve, as it provides a direct and accurate assessment of the number of ovarian follicles. However, the relationship between ovarian reserve and oocyte quality is not well understood, and further research is needed to fully understand the implications of these test results for IVF outcomes. Study design, size, duration The present retrospective case-control study, performed between 2015 and 2021, aims to investigate the association between ORTs and the rate of euploid embryos conceived through ICSI. 680 patients underwent in vitro fertilization procedures that included blastocyst biopsy and 23-chromosome aneuploidy testing. Regardless of cycle day, a level greater than 1,2 ng/mL was regarded as normal, less than 10 antral follicles in total were associated with diminished ovarian reserve according to current knowledge. Participants/materials, setting, methods AMH and AFC were studied to determine their relationship with rates of abnormal embryo development. Patients were divided into two groups based on their baseline hormone levels. The AMH group (n = 680) had 562 individuals with normal ovarian reserve in Group 1 and 118 with lower reserve in Group 2. A similar division was made in the same group based on AFC values, resulting in 210 patients with low AFC and 348 with normal AFC. Main results and the role of chance Low AMH Group was made up of slightly older patients, as would be expected (39,9 compared with 40,41 years for group 1; P = 0,193). Patients with low AMH shown FSH levels significantly higher (P = 0,022) compared to those with normal ones. Not surprisingly, aspirated follicles, oocytes retrieved, pre-ovulatory follicles, fertilizable oocyte, fertilized oocytes and evolutionary embryos appeared significantly higher in people with normal levels of AMH (respectively P<0,01; P<0,01; P = 0,004; P = 0,013; P = 0,009; P = 0,015). This means the latter had a better oocyte quality even though they shown a comparable non-evolutionary embryo mean (P = 0,047). Regarding euploid embryos, it didn’t result in a statistically significant difference between the 2 groups (P = 0,14) AMH cohort and (P = 0,12) AFC cohort. We obtained the almost the same results taking into account AFC cohort. As expected, regarding protocols and gonadotropins used to stimulate women, our data shown a statistically significant value (P = 0,016) due to personalized protocols for women predicted as poor or normal/high responders. Limitations, reasons for caution There are many points affecting diminished ovarian reserve (DOR), linked to a variety of etiologies. However, the genetic determinants of DOR remain largely unknown. All these features don’t allow making an easy model for better studying this condition. Wider implications of the findings This study can help clinics provide more accurate and informative counseling to patients undergoing IVF, by giving them a better understanding of the factors that affect their chances of success and how they can impact their treatment. Trial registration number None

The effect of parental carrier of de novo mutated vs. inherited balanced reciprocal translocation on the chance of euploid embryos

To evaluate whether the effect of de novo mutated balanced reciprocal translocation on the rate of euploid embryos varied from inherited balanced reciprocal translocation. A retrospective cohort study compared the percentage of euploid embryo and proportion of patients with at least 1 euploid embryo between de novo mutated balanced reciprocal translocation (i.e., the group of de novo mutated carriers) and inherited balanced reciprocal translocation (i.e., the group of inherited carriers). An academic fertility center. A total of 413 couples with balanced reciprocal translocation (219 female carriers and 194 male carriers) who underwent their first cycle of preimplantation genetic testing for structural rearrangements were included. Carriers of balanced reciprocal translocation either de novo mutated or inherited. The percentage of euploid embryo and proportion of patients with at least 1 euploid embryo. The carriers of the de novo mutated balanced reciprocal translocation had a lower percentage of euploid embryos (19.5% vs. 25.5%), and were less likely to have at least 1 euploid embryo (47.1% vs. 60.1%) compared with the carriers of the inherited balanced reciprocal translocation. In the male-carrier subgroup, the percentage of euploid embryos (16.7% vs. 26.7%) and proportion of patients with at least 1 euploid embryo (41.9% vs. 67.5%) were lower among the de novo mutated carriers than those among the inherited carriers. However, in the female-carrier subgroup, there was no statistically significant difference in the percentage of euploid embryos (22.4% vs. 24.4%) or the proportion of patients with at least 1 euploid embryo (52.3% vs. 53.7%) between the de novo mutated carriers and inherited carriers. The de novo mutated balanced reciprocal translocation was associated with a lower percentage of euploid embryos and lower chance of obtaining at least 1 euploid embryo than the inherited balanced reciprocal translocation.

Medroxyprogesterone acetate: an alternative to GnRH-antagonist in oocyte vitrification for social fertility preservation and preimplantation genetic testing for aneuploidy

Research questionCan medroxyprogesterone acetate (MPA) be used as a pituitary suppressor instead of a gonadotrophin releasing hormone (GnRH) antagonist during ovarian stimulation in elective fertility preservation and preimplantation genetic testing for aneuploidy (PGT-A) cycles? DesignA multicentre, retrospective, observational, cohort study conducted in 11 IVIRMA centres affiliated to private universities. Of a total of 1652 cycles of social fertility preservation, 267 patients were stimulated using a progestin-primed ovarian stimulation protocol (PPOS), and 1385 patients received a GnRH antagonist. In the PGT-A cycles, 5661 treatments were analysed: 635 patients received MPA and 5026 patients received GnRH antagonist. A further 66 fertility preservation and 1299 PGT-A cycles were cancelled. All cycles took place between June 2019 and December 2021. ResultsIn the social fertility preservation cycles, the number of mature oocytes vitrified in MPA was similar to the number of those treated with an antagonist, a trend that was seen regardless of age (≤35 or >35 years). In the PGT-A cycles, no differences were found in number of metaphase II, two pronuclei, number of biopsied embryos (4.4 ± 3.1 versus 4.5 ± 3.1), rate of euploidy (57.9% versus 56.4%) or ongoing pregnancy rate (50.4% versus 47.1%, P = 0.119) between the group receiving MPA versus a GnRH antagonist, whereas the clinical miscarriage rate was higher in the antagonist group (10.4% versus 14.8%, P = 0.019). ConclusionsAdministration of PPOS yields similar results to GnRH antagonists in oocytes retrieved, rate of euploid embryos and clinical outcome. Hence, PPOS can be recommended for ovarian stimulation in social fertility preservation and PGT-A cycles, as it allows greater patient comfort.

P-672 Progestin primed ovarian stimulation: whether there is an effect on embryo euploidy and pregnancy rate in IVF programs with donor oocytes

Abstract Study question Is there a difference in euploid embryo rates and pregnancy rates in IVF programs with donor oocytes after PPOS and GnRH-antagonist programs ? Summary answer We report no difference in euploid embryo rates and pregnancy rates in IVF programs with donor oocytes after PPOS and GnRH-antagonist programs. What is known already Before the advances in vitrification techniques, it was impossible to consider the feasibility of using steroids during controlled ovarian stimulation since it negatively impacts endometrial receptivity. Since it is possible to cryopreserve and thaw embryos, the frozen-embryo transfer has been widely used. Progesterone soft gels have recently been shown to be an effective oral alternative for preventing premature LH surges during COH in normally ovulating women undergoing IVF/ICSI procedures with optimal pregnancy outcomes at transfer frozen-thawed embryos cycles. Thus, PPOs may be a priority choice for ovarian stimulation in the cycle of fertility preservation, oocyte donation, and preimplantation genetic testing. Study design, size, duration A retrospective cohort study of 201 IVF/ICSI programs with donor oocytes from January 2018 to September 2020. Participants/materials, setting, methods All programs were divided into 2 groups: 1 st group - 123 programs for the stimulation of oocyte donors with progestins primed ovarian stimulation, 2nd group - 93 programs with Cetrorelix as an LH peak blocker. We compared the number of mature oocytes, fertilization rate, blastulation rate, blastocyst and TQB quality, and euploid embryo rate after the preimplantation genetic screening with aCGH. Main results and the role of chance In our study, there were no statistically significant differences in the dose of gonadotropins in the groups, but the number of injections in the α group was less due to the exclusion of parenteral administration of antagonists and agonists, which improved the quality of life of donors during stimulation. There were no cases of stimulation complications in any group. The number of mature oocytes in both groups of oocyte donors did not differ (80 vs. 81%, respectively p ∠0.001.). The percentage of fertilization (80.8% in the 1st group and 77.5% in the 2nd group) and the frequency of blastulation (51.4% in the 1st group and 53.5% in the 2nd group) did not have significant differences both in the group with Utrozhestan and in the group with Cetrorelix. . The number of TQBs (68.8% vs. 66.4%) p∠0.001. and the level of euploid embryos in both groups was the same (51% vs. 59%) p ∠0.05. The pregnancy rate in both groups also did not differ significantly (50.7% in the 1st group versus 41.5% in the 2nd group p∠ 0.001.). Limitations, reasons for caution The limitations are related to the study design. More research is also needed. Wider implications of the findings Thus, the progesterone protocol is effective, safe, convenient for oocyte donation, for patients with spontaneous ovulation in previous stimulation protocols, for patients with confirmed follicular luteinization in previous stimulation protocols. PPOS does not worsen the pregnancy rate and the number of euploid embryos in the program with donor oocytes. Trial registration number not applicable

P-525 PGT-A with embryo pooling: does it result in a higher yield of euploid embryos and better clinical pregnancy outcomes?

Abstract Study question Does PGT-A with embryo pooling result in a higher yield of euploid embryos and better clinical pregnancy outcomes compared to PGT-A done after one cycle? Summary answer There is no evidence to support that embryo pooling for PGT-A purposes is favorable in preference to PGT-A after one cycle. What is known already PGT-A has been the method of choice that is thought to optimize embryo selection and enhance clinical outcomes. However, the number of embryos available for biopsy can be a source of limitation, as the yield of euploid embryos suitable for transfer can be affected when lower number of embryos are available for screening. A protocol that is suggested to overcome this limitation is to undergo multiple IVF/ICSI cycles with blastocyst biopsy and embryo pooling, then proceed with PGT-A screening once a sufficient number of biopsied embryos is attained. Study design, size, duration This is a retrospective study that included ICSI cycles from June 2019 to December 2021, involving 157 patients (average maternal age 36.4) that underwent PGT-A after one ICSI cycle (group A), and 79 patients (average maternal age 35.6 ) that underwent PGT-A after embryo pooling from more than one ICSI cycle (Group B). Patients in group B underwent pooling due to cost implications on the number of embryos to screen. Participants/materials, setting, methods A total of 843 embryos were biopsied and screened for group A, and 536 were biopsied and screened for group B. Following PGT-A screening, a number of frozen embryo transfers (FET) were conducted (120, 67 respectively). Investigations included: number of embryos available for biopsy, number of euploid embryos and clinical pregnancy outcomes after FET. Statistical analysis was calculated (P < 0.05). Main results and the role of chance Patients in group A proceeded with PGT-A after only one ICSI cycle, while in group B patients underwent 2.3 cycles on average. The average number of embryos suitable for biopsy was 5.4, and 6.9 per patient respectively. The rate of euploid embryos was 42.1% and 43.8%, and the average number of euploid embryos per patient was 5.4 and 6.5 respectively. A total of 144 embryos were transferred in group A with an average of 1.2 embryos per patient. Clinical pregnancy rate (CPR) was 60%, implantation rate was 54.9% and live birth rate (LBR) was 35.8%. In Group B a total of 67 embryos were transferred with an average of 1.1 embryos per patient. Clinical pregnancy rate (CPR) was 67.7%, implantation rate was 68.7% and live birth rate (LBR) was 40%. No significant difference was observed between both groups for clinical outcomes (P > 0.05). Limitations, reasons for caution This study is retrospective and small in size. Data on live birth rate requires further follow up as a number of patients are still in ongoing pregnancies. A larger data set study is needed to support conclusion. Wider implications of the findings Results from this study does not support the adoption of a pooling strategy for patients undergoing PGT-A. Although the number of embryos available for biopsy may increase slightly, the yield of euploid embryos is not significantly increased and the clinical pregnancy rate is not enhanced. Trial registration number not applicable

P-632 Evaluation of low AMH levels in young women

Abstract Study question The primary objective was to evaluate impact of a low AMH level on the live birth rate in a population of young women IVF/ICSI . Summary answer Low AMH level in young women in FIV/ICSI is not expected to have an impact on the live birth. What is known already AMH is an important criterion for defining ovarian reserve. The majority of studies have shown that the AMH level in the general population is not correlated with the chances of spontaneous pregnancy. The management remains a challenge and must be individualized taking into account the new quantitative and qualitative criteria to be defined (POSEIDON classification). Finally, we know that the pregnancy rate is correlated to the rate of euploid embryos, and that the rate is higher before 35 years of age. Study design, size, duration In this single-center retrospective study from January 2015 to December 2020, 1824 IVF/ICSI attempts were analyzed. We analyzed the live birth rate according to 2 categories of young women matched by AMH level. Participants/materials, setting, methods We analyzed the live birth rate according to 2 categories of young women managed in IVF/ICSI protocol. A first group was ≤30 years old and a second group was between 31 and 35 years old. Then, we matched each of these groups to an AMH level, AMH<1ng/mL and AMH ≥1ng/mL. We analyzed the live birth rate of 4 groups of young women. Main results and the role of chance 1824 IVF/ICSI attempts were analyzed in this study. We have 539 women under 30 years of age and 1285 women between 31 and 35 years of age. For women aged ≤30 years, the group with AMH<1ng/mL had a non-statistically significant live birth rate compared to those with AMH≥1ng/mL (31% vs 32.7% p = 1). For women aged 31-35 years, the group with AMH<1ng/mL, has a statistically significant lower live birth rate compared to those with AMH≥1ng/mL (14.5% vs 29.3% p = 0.001). Limitations, reasons for caution The main limitation of our study is the few number of patients. Wider implications of the findings This study tries to demonstrate that low AMH levels in young women do not predict a poor IVF/ICSI success rate. Conclusions should not be drawn too quickly for low AMH in this population. However, the threshold AMH level is still debated in the studies and should be further adjusted. Trial registration number not applicable

Euploidy rates among preimplantation genetic testing for aneuploidy cycles with oral dydrogesterone primed ovarian stimulation or GnRH antagonist protocol

Research questionDo differences exist in euploidy rates in preimplantation genetic testing for aneuploidy (PGT-A) cycles with oral dydrogesterone primed ovarian stimulation protocol or the flexible gonadotropin-releasing hormone (GnRH) antagonist protocol? DesignA retrospective cohort study. Patients received the oral dydrogesterone or the GnRH antagonist in the first PGT-A cycle between November 2017 and May 2019. Propensity matching was used to identify a propensity-matched antagonist group based on age, BMI and AMH with a 1:1 ratio. The primary outcome was the rate of euploid embryos. ResultsA total of 780 cycles were included, consisting of 390 cycles receiving dydrogesterone and 390 cycles receiving GnRH antagonist protocol. No significant difference was found in patient baseline and cycle characteristics in the two groups. No statistical difference was found in the number of oocytes retrieved, metaphase II oocytes, embryos biopsied and embryo testing between the two groups. As no biopsy blastocysts formed in some cycles, only 262 cycles in the study group and 263 cycles in the antagonist group received next-generation sequencing testing, respectively. Similar to our overall data, the euploid rate per embryo biopsied was not significantly different. No significant differences were found between the two groups after stratifying by age and controlling for PGT-A testing modality. ConclusionsOvulation inhibition by exogenous progestins in ovarian stimulation cycles should, therefore, be considered a valid modality in freeze-all PGT-A cycles, in view of its demonstrated effectiveness and known safety enhancement.

Reproductive outcomes in individuals with chromosomal reciprocal translocations

PurposePatients with reciprocal balanced translocations (RBT) have a risk for recurrent pregnancy losses (RPL), affected child, and infertility. Currently, genetic counseling is based on karyotypes found among the products of conception (POC), although factors influencing the success of assisted reproductive technologies (ART) in RBT couples are not established. MethodsCytogenetic results from 261 POC and offspring of the parents (113 women and 90 men) with RBT were evaluated. Chromosome segregation modes and number of euploid embryos were assessed in couples undergoing in vitro fertilization. ResultsPatients with translocations involving an acrocentric chromosome have a higher risk of unbalanced gametes caused by a 3:1 segregation. Female RBT patients have a statistically higher risk of aneuploidy due to an interchromosomal effect. The rate of euploid embryos is low due to meiosis I malsegregation of RBT, meiosis II nondisjunction, additional whole chromosome or segmental aneusomies. RBT patients with RPL have a higher rate of miscarriage of euploid fetuses with RBT. ConclusionChromosome-specific factors, female gender, age, and history of RPL are the risk elements influencing pregnancy and in vitro fertilization success in RBT patients. Chromosomal microarray analysis of POC is necessary to provide an accurate and timely diagnosis for patients with adverse reproductive outcomes.

P–158 Assisted Hatching on D + 3 in order to facilitate trophectoderm biopsy in blastocyst for PGT-A is not advisable in all patients

Abstract Study question Is it useful or beneficial to perform Assisted Hatching (AH) on D + 3 previously to biopsy for PGT-A on blastocyst stage on D + 5? Summary answer The routine use of AH on D + 3 to facilitate the embryo biopsy on D + 5 could negatively influence the development of the embryos to blastocyst stage. What is known already The blastocyst stage is the optimal stage for performing biopsies for PGT-A, which has been reported as a key factor determining the growing clinical application of this strategy worldwide. For trophectoderm (TE) biopsy, laser-assisted drilling is used to create a zona opening on D + 3 or D + 5 of development. The method of zona opening on D + 3 allows some of the TE cells to herniate during blastocyst formation and expansion, which facilitates the biopsy process. However, this method may result in herniation of inner cell mass cells instead of TE or maybe could affect the development of the embryo to blastocyst stage. Study design, size, duration A total of 100 PGT-A cycles were performed in 2019 and 2020. In 78 of them laser-assisted drilling was used to create a zona opening on D + 5 only in those embryos which arrived to blastocyst stage for TE biopsy (Group No-AH). In 22 cycles the same drilling was achieved on D + 3 in all embryos, independently of their quality (Group AH). The average of embryos per cycle in each group was 5 and 4.3 respectively. Participants/materials, setting, methods A total of 100 PGT-A cycles coming from 65 patients were studied. The average of the age of the patients was 40.83 (SD 3.45) in the group No-AH vs 42.18 (SD 3.42) in the Group AH (p = 0.108), so the age was not a determining factor for the development of the embryos. We analyzed by χ 2 test differences between groups on fertilization rates, number of embryos, development to blastocyst stage, euploidy and pregnancy rates. Main results and the role of chance The fertilization rate was 74.79% (No-AH group) and 68.53% (AH group) with no significative statistical differences (p = 0.12). In the No-AH group, the TE biopsy was performed on D + 5 in 63 cycles (81%). In the AH group, 41% of cycles didn’t reach the blastocyst stage, obtaining statistical differences between groups (p = 0.035). We found also significant differences in the number of cycles with biopsied blastocyst when we had 1 to 6 embryos/cycle on D + 3 between groups (p = 0.002), without obtaining any blastocyst to be diagnosed in 53% of the cycles in AH group vs 27% in No-AH group. When the number of embryos on D + 3 per cycle was > 6, at least 1 embryo reached the blastocyst stage in both groups, although this number was higher in No-AH group. The rate of biopsied blastocysts was significantly higher in the No-AH group compared to the AH group (46.61 vs 34.69) with a p = 0.031. The rate of euploid embryos analyzed was 23.30% in the No-AH group compared to 29.41% in the AH group, although no significant differences were found (p = 0.44) between groups. In the No-AH group, a clinical pregnancy rate of 52.94% was obtained (n = 34) vs 50% in the AH group (n = 4) (p = 0.91). Limitations, reasons for caution We have recently started to perform AH on D + 3, so the number of cases is smaller than No-AH group. We use a time lapse incubator in all cases, so in the No-AH the culture dish is changed, disturbing the stable incubation environment, while in the other group it is not. Wider implications of the findings: The use of AH on D + 3 in order to facilitate the TE biopsy on D + 5 could affect negatively the development of the embryos to blastocyst stage. Its routine use should be avoided based on laboratory workload, mainly if the patient has less than 7 embryos at D + 3. Trial registration number Not applicable

P–390 The intrauterus administration of peripheral blood mononuclear cells increase the pregnancy rates for the patients with advanced maternal age after single euploid embryo transfer

Abstract Study question Does the intrauterine administration of peripheral blood mononuclear cells (PBMCs) effect the outcome of IVF for patients with advanced maternal age when the euploid embryos after PGT-A are transferred? Summary answer The implantation rates were significantly higher after the intrauterine application of PBMCs in patients with advanced maternal age (AMA) before transfer of the euploid embryo. What is known already The aneuploidy rates of blastocysts in IVF is in range 45–70% depending on different factors. Besides that, the endometrium plays an important role in achieving optimal outcomes of assisted reproductive technologies. It has been proposed that intrauterine administration of peripheral blood mononuclear cells modulates maternal immune response to favor implantation. Study design, size, duration The effect of the intrauterine application of PBMCs to improve the implantation rates in the group of patients with advanced maternal age was studied. Two group of patients (PBMCs-group and non-PBMCs-group_ were formed. Single euploid embryo was transferred for each patient. Participants/materials, setting, methods: The ploidy status of 373 blastocysts from 82 AMA-patients was analyzed by the method of next generation sequencing (NGS). PBMCs were applied for 39 women with the mean age 39.2±3.2 y.o. before embryo transfer (Group 1). For 43 patients with the mean age 38.2±2.1 y.o. single euploid embryo transfers were performed without PBMCs administration (Group 2). Chi-squared test was used for data analysis. The study’s protocol was approved by the Center’s IRB. Main results and the role of chance Totally the rate of euploid embryos was 27.1% (101 blastocysts). In the mentioned study 55.0% of examined blastocysts were aneuploid (205 embryos) and 17.9% of blastocysts were detected as mosaic (67 embryos). Single euploid embryo was transferred in each case in the patients of both experimental groups. The implantation rate was significantly higher in Group 1 with PBMCs application comparing with non-PBMCs experimental Group 2 (38.5% (15 pregnancies) vs. 23.3% (10 pregnancies), df = 1, χ2 = 5.487, χ2critical = 3.841, P = 0.020). Limitations, reasons for caution The embryo biopsy was performed only for blastocyst with top-quality morphology. Wider implications of the findings: The implantation rates were significantly higher when the intrauterine application of PBMCs in patients with advanced maternal age before the transfer of the euploid embryo (P = 0.020). The randomized studies to improve our knowledge in immunogenic therapy in reproductive medicine should be performed. Trial registration number -

Elevated serum progesterone does not impact euploidy rates in PGT-A patients.

Some women undergoing stimulated cycles have elevated serum progesterone (P) on the day of ovulation trigger, but its effect on embryo quality is unclear. We analyze embryo quality among patients with high and low serum P undergoing preimplantation genetic testing for aneuploidy (PGT-A). This retrospective study included 1597 patients divided into two groups by serum P values: < 1.5 ng/mL or ≥ 1.5 ng/mL. A gonadotrophin-releasing hormone (GnRH) antagonist protocol was established for each patient. Serum P levels were measured on the day of triggering. Propensity score matching and Poisson regression were done. Age, body mass index, and ovarian sensitivity index were also compared. Elevated serum P was not significantly associated with euploid embryo rate or other embryo-quality variables evaluated in our study. Age was the only variable associated with euploidy rate (per MII oocyte, P < 0.001; per biopsied embryo, P = 0.008), embryo biopsy rate (P < 0.001), absolute number of euploid embryos (P = 0.008), and top-quality embryo rate (P = 0.008). Categorical variables decreased in value for every year of increased age in patients with high serum P. Elevated serum P did not affect the number of euploid and good-quality embryos for transfer in GnRH antagonist intracytoplasmic sperm injection (ICSI) cycles. Contrary to the clear influence of premature P elevation on endometrial receptivity based on literature, our results may help to tip the balance towards the absence of a negative effect of P elevation on embryo competence. More studies are needed to fully understand the effect of P elevation on reproductive outcomes.

Conventional ICSI improves the euploid embryo rate in male reciprocal translocation carriers.

To evaluate whether the morphologically normal spermatozoa selected for intracytoplasmic sperm injection (ICSI) under microscope had a higher rate of normal/balanced chromosome contents than that in the whole unselected sperm from reciprocal translocation carriers. Five hundred unselected spermatozoa from each of 40 male translocation carriers were performed with fluorescence in situ hybridization (FISH), to determine the rates of gametes with different meiotic contents of translocated chromosomes. Meanwhile, 3030 biopsied blastocysts from 239 male and 293 female reciprocal translocation carriers were detected with the microarray technique to analyze the rates of embryos with different translocated chromosome contents. The D3 embryo rate, blastocyst formation rate, and euploid rate of blastocysts were remarkably higher in male carriers than those in female (p = 0.001, p = 0.004, and p = 0.035, respectively). In addition, the percentages of alternate products, which contained normal/balanced chromosome contents, in embryos from male carriers were markedly higher than those in sperm FISH (p = 2.48 × 10-5 and p = 2.88 × 10-10), while the percentages of adjacent-2 and 3:1 products were lower than those in sperm FISH (p = 0.003 and p = 5.28 × 10-44). Moreover, consistent results were obtained when comparing the rates of products in embryos between male and female carriers. Specifically, the incidence of alternate products in male carriers was higher than those in female carriers (p = 0.022). However, no similar differences were seen between sperm and embryos of female carriers. ICSI facilitates the selection of spermatozoa with normal/balanced chromosome contents and improves the D3 embryo rate, blastocyst formation rate, and the euploid embryo rate in male carriers.

The influence of balanced complex chromosomal rearrangements on preimplantation embryonic development potential and molecular karyotype

BackgroundBalanced complex chromosome rearrangements (BCCR) are balanced chromosomal structural aberrations that involve two or more chromosomes and at least three breakpoints. It is very rare in the population. The objective is to explore the difference of influence of three types of BCCR on early embryonic development and molecular karyotype.ResultsTwelve couples were recruited including four couples of three-way rearrangements carriers (group A), three couples of double two-way translocations carriers (group B) and five couples of exceptional CCR carriers (group C). A total of 243 oocytes were retrievedin the seventeen preimplantation genetic testing (PGT) cycles, and 207 of these were available for fertilization. After intracytoplasmic sperm injection, 181oocytes normally fertilized. The rates of embryos forming on day3 in three groups were 87.88, 97.78 and77.14%, which was significantly different (P = 0.01). Compared with group B, the rate of embryo formation was statistically significantly lower in group C (P = 0.01). Furthermore, the rates of high-quality blastocysts in three group were 14.71, 48.15 and 62.96%, respectively, which was significantly different (P = 0.00). Compared with group B andC, the rate of high-quality blastocysts in group A was statistically significantly lower (P = 0.00;P = 0.00).Comprehensive chromosome analysis was performed on 83 embryos, including 75 trophectodermcellsand 8 blastomeres. Except 7 embryos failed to amplify, 9.01%embryos were diagnosed as euploidy, and 90.91% were diagnosed as abnormal. As for group A, the euploid embryo rate was 10.71%and the abnormal embryo rate was 89.29%. In group B,the euploid embryo rate was 3.85%, the abnormal embryo rate was 96.15%. The euploid embryo rate was 13.04%, the abnormal embryo rate was 86.96% in group C. There were no significant differences among the three groups (P = 0.55).ConclusionsThe lowest rate of high quality blastocysts has been for three-way rearrangements and the lowest rate of euploidy has been for double two-way translocations, although no significant difference. Different types of BCCR maybe have little effect on the embryonic molecular karyotype. The difference of influence of BCCR on early embryonic developmentandmolecular karyotypeshould be further studied.

15.IMPACT OF MATERNAL AGE IN THE INCIDENCE OF UNIFORM AND MOSAIC ANEUPLOIDIES

Introduction Female fertility decreases with age and increases the incidence of aneuploidies mostly due to meiotic errors. The incidence of aneuploid embryos turn around 60% confirming the high abortion rates observed by the presence of chromosomal aneuploidies. Next generation sequencing (NGS) proved to be the most appropriate technology for aneuploidy testing in trophectoderm biopsies, with accurate results, high throughput and cost efficiency. However, the rates and levels of embryonic mosaicism are still a subject of discussion. It is known that they can lead to miscarriage and birth defects but the data linking advanced maternal age and mosaicism is limited. Thus, this study aims to assess the differences between the incidence of different levels of mosaicism and uniform aneuploidies in blastocyst biopsies according to maternal age to verify if they follow a similar pattern. Material & methods A total of 34,387 blastocyst biopsies were sent for PGT-A analysis between October and December 2018 from private assisted reproduction centers to our laboratory. NGS technology (ThermoFisher platform) combined with diagnosis a proprietary validated algorithm was used to optimize results. Patients were stratified by age in seven groups: 50% - 30% - Results 33,341 biopsies were informative with 6% (n=1997) of total mosaicism, 47% uniform aneuploidy (n= 15.670) and 47% euploid biopsies (n=15.674). Regarding the mosaicism rates, 65.3 % (n= 1305) were low mosaic degree, and 34.6% (n=692) were high mosaic degree. A significant decrease (p Conclusions The rate of euploid embryos decreased with advanced maternal age and aneuploidies increased, corroborating previous data from other studies. Regarding mosaicism different trends were observed for low mosaic degree, with a trend towards a decrease of low mosaic degree with maternal age, and high mosaic degree without an effect of maternal age.