Poor Quality Embryos Research Articles

Immature oocyte proportion in a cohort led to poor embryo development but did not reduce clinical pregnancy rate

PurposeThis study aimed to evaluate the effects of immature oocyte proportion in a cohort on both IVF laboratory and clinical outcomes.Materials and methodsThis retrospective cohort study took place at Morula IVF Jakarta Clinic from January 2016 to July 2020. A total of 1.826 couples undergoing IVF-ICSI/IMSI were included and classified into four groups according to the proportion of immature oocytes retrieved during OPU as follows: (1) immature ≤ 15% (n = 1.064), (2) immature 16–25% (n = 369), (3) immature 26–50% (n = 331), and (4) immature > 50% (n = 62). Primary outcomes were clinical pregnancy and miscarriage. Embryology laboratory results were assessed as the secondary outcomes. Statistical analyses were carried out utilizing Kruskal–Wallis or chi-square tests. p-value < 0.05 was considered statistically significant.ResultsIncreased proportion of immature oocytes in a cohort was significantly associated with body mass index, tubal factors, and estradiol level on trigger day (p < 0.05). Neither clinical pregnancy nor miscarriage was associated with the immature oocyte proportion (adjusted p-value = 0.872 and p = 0.345, respectively). However, a higher proportion of immature oocytes significantly reduced the total number of fertilized oocytes, number of top-quality cleavages, and blastocysts (p < 0.001). Furthermore, embryo transfer cancelation rates due to poor embryo quality were elevated significantly.ConclusionDespite overall poor embryo development in the laboratory, our study seems to suggest that the proportion of immature oocytes in a cohort has no impact on clinical pregnancy and miscarriage rate in IVF program.

Impact of inclusion of a poor-quality embryo with a good-quality embryo on pregnancy outcomes in vitrified-warmed blastocyst transfers

Research questionDoes the co-transfer of a good-quality embryo and a poor-quality embryo influence pregnancy outcomes in comparison to the transfer of a single good-quality embryo in vitrified-warmed blastocyst transfer cycles? DesignThis retrospective cohort study involved a total of 11,738 women who underwent IVF/intracytoplasmic sperm injection cycles and vitrified-warmed blastocyst transfer at a tertiary-care academic medical from January 2015 to June 2022. The study population was categorized into two groups: single-blastocyst transfer (SBT; participants who underwent single good-quality embryo transfer, n = 9338) versus double-blastocyst transfer (DBT; participants who underwent transfers with a poor and a good-quality embryo, n = 2400). ResultsThe live birth rate (LBR) was significantly higher in the DBT group in comparison with the SBT group (65.6% versus 56.3%, P < 0.001). Multivariable logistic regression analysis showed that DBT was an independent predictor for LBR with a strong potential impact (adjusted odds ratio 1.55, 95% confidence interval 1.41–1.71; P < 0.001). However, the multiple birth rate was significantly higher in the good-quality embryo and poor-quality embryo group compared with patients undergoing a single good-quality embryo transfer (41.4% versus 1.8%; P < 0.001). ConclusionsIn vitrified-warmed blastocyst transfer cycles, LBR was higher following DBT with one good-quality and one poor-quality embryo compared with SBT. However, this was at the expense of a marked increase in the likelihood of multiple gestations. Physicians should still balance the benefits and risks of double-embryo transfer.

Paraspeckles / CARM1 mediates the regulation of OEVs on cell differentiation during in vitro embryonic development of yak

Mammalian embryos produced in vitro have poor embryo quality and low developmental ability compared with in vivo embryos. The main manifestations are the low number of blastocysts, the low ratio of the number of inner cell mass cells to the number of trophoblastic cells, and the high apoptosis rate of blastocysts, resulting in low embryo implantation rate. Therefore, optimizing in vitro culture conditions has become a key technology to im-prove the quality of preimplantation embryos. Oviduct Epithelial cells exosomes (OEVs) can be absorbed and internalized by embryos to improve the blastocyst rate and blastocyst quality of embryos in vitro. As a special nuclear structure, Paraspeckles are involved in the fate determination of mammalian early embryonic mammalian cells. However, the regulation of embryonic cell differentiation by OEVs remains unknown. We aimed to investigate the effects of OEVs on paraspeckle formation and cell fate determination in yak in vitro fertilization (IVF) of em-bryos. To simulate the in vivo oviduct environment after ovulation, we used follicular fluid exosomes (FEVs) to stimulate yak oviduct epithelial cells and collect OEVs. OEVs were added to the yak IVF embryo culture system. Paraspeckle formation, cell differentiation, and blastocyst quality in yak embryos were determined. Our results show that, development of yak embryos is unique compared to other bovine species, and OEVs can be used as a supplement to the in vitro culture system of yak embryos to improve embryonic development and blas-tocyst quality. And also Paraspeckles/CARM1 mediated the regulation of OEVs on cell differentiation during in vitro yak embryo production. These results provide new insights into the study of yak embryonic development and the role of OEVs in embryonic development.

Preimplantation genetic testing for aneuploidy: predictive embryonic factors.

In a preimplantation genetic testing for aneuploidy (PGT-A) cycle, does the blastocyst quality before biopsy, or the day of biopsy, or the embryo hatching status have an impact on either euploidy or the rate of embryo survival after freezing? This was a retrospective study including 6130 biopsied blastocysts coming from 1849 PGT-A cycles performed in our center (2016-2022). Embryos were categorized according to the inner cell mass and trophectoderm quality, using Gardner's scoring (excellent: AA; good: AB, BA, BB; poor: AC, CA, BC, CB, CC); the day of biopsy (5 or 6); and their hatching status (fully hatched blastocysts [FHB] or non-fully hatched blastocysts [nFHB]). The independent relationship between each group and both euploidy and survival rate was assessed. Excellent-quality embryos were more euploid than both good- and poor-quality embryos (52.69%, 39.69%, and 26.21%; p < 0.001), and day 5-biopsied embryos were more euploid than day 6-biopsied embryos (39.98% and 34.80%; p < 0.001). Survival rates of excellent-quality (92.26%) and good-quality (92.47%) embryos were higher than survival rates in the poor-quality group (84.61%) (p = 0.011 and p = 0.002). Day 5-biopsied embryos survived better than day 6-biopsied embryos (93.71% vs. 83.69%; p < 0.001) and FHB had poorer survival than nFHB (78.61% vs. 93.52%; p < 0.001). Excellent-quality and day 5-biopsied embryos are more prone to be euploid than good and poor or day 6-biopsied embryos, respectively. Poor-quality, day 6-biopsied embryos, and FHB have significantly lower survival after biopsy and vitrification.

Effect of frozen-thawed embryo transfer with a poor-quality embryo and a good-quality embryo on pregnancy and neonatal outcomes.

To evaluate the impact of embryo quality and quantity, specifically a poor quality embryo (PQE) in combination with a good quality embryo (GQE), by double embryo transfer (DET) on the live birth rate (LBR) and neonatal outcomes in patients undergoing frozen-thawed embryo transfer (FET) cycles. A study on a cohort of women who underwent a total of 1462 frozen-thawed cleavage or blastocyst embryo transfer cycles with autologous oocytes was conducted between January 2018 and December 2021. To compare the outcomes between single embryo transfer (SET) with a GQE and DET with a GQE and a PQE, propensity score matching (PSM) was applied to control for potential confounders, and a generalized estimating equation (GEE) model was used to determine the association between the effect of an additional PQE and the outcomes. Subgroup analysis was also performed for patients stratified by female age. After PS matching, DET-GQE + PQE did not significantly alter the LBR (adjusted odds ratio [OR] 1.421, 95% CI 0.907-2.228) compared with SET-GQE in cleavage-stage embryo transfer but did increase the multiple birth rate (MBR, [OR] 3.917, 95% CI 1.189-12.911). However, in patients who underwent blastocyst-stage embryo transfer, adding a second PQE increased the live birth rate by 7.8% ([OR] 1.477, 95% CI 1.046-2.086) and the multiple birth rate by 19.6% ([OR] 28.355, 95% CI 3.926-204.790), and resulted in adverse neonatal outcomes. For patients who underwent cleavage-stage embryo transfer, transferring a PQE with a GQE led to a significant increase in the MBR ([OR] 4.724, 95% CI 1.121-19.913) in women under 35 years old but not in the LBR ([OR] 1.227, 95% CI 0.719-2.092). The increases in LBR and MBR for DET-GQE + PQE compared with SET-GQE in women older than 35 years were nonsignificant toward. For patients who underwent blastocyst-stage embryo transfer, DET-GQE + PQE had a greater LBR ([OR] 1.803, 95% CI 1.165-2.789), MBR ([OR] 24.185, 95% CI 3.285-178.062) and preterm birth rate (PBR, [OR] 4.092, 95% CI 1.153-14.518) than did SET-GQE in women under 35 years old, while no significant impact on the LBR ([OR] 1.053, 95% CI 0.589-1.884) or MBR (0% vs. 8.3%) was observed in women older than 35 years. The addition of a PQE has no significant benefit on the LBR but significantly increases the MBR in patients who underwent frozen-thawed cleavage-stage embryo transfer. However, for patients who underwent blastocyst-stage embryo transfer, DET-GQE + PQE resulted in an increase in both the LBR and MBR, which may lead to adverse neonatal outcomes. Thus, the benefits and risks of double blastocyst-stage embryo transfer should be balanced. In patients younger than 35 years, SET-GQE achieved satisfactory LBR either in cleavage-stage embryo transfer or blastocyst-stage embryo transfer, while DET-GQE + PQE resulted in a dramatically increased MBR. Considering the low LBR in women older than 35 years who underwent single cleavage-stage embryo transfer, selective single blastocyst-stage embryo transfer appears to be a more promising approach for reducing the risk of multiple live births and adverse neonatal outcomes.

Evaluation of Oxidative and Nitrosative Stress Markers Related To Inflammation in The Cumulus Cells and Follicular Fluid of Women Undergoing Intracytoplasmic Sperm Injection: A Prospective Study.

Oxidative/nitrosative stress in the oocyte microenvironment could have an impact on intracytoplasmic sperm injection (ICSI) outcomes. The presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) can stimulate the secretion of pro-inflammatory cytokines, leading to chronic inflammation and potentially affecting embryo as well as oocyte quality. This study aimed to examine the relationship of lipid peroxidation [measured by the malondialdehyde (MDA) assay] with protein carbonyl [measured by the 2,4 dinitrophenylhydrazine (DNPH) assay] levels in cumulus cells (CCs), as well as nitric oxide (NO), peroxynitrite (ONOO-), and C-reactive protein (CRP) levels in follicular fluid (FF). The potential relationship of these levels with ICSI outcome was also evaluated. In this prospective study, 63 FF samples and their corresponding CCs were collected for ICSI procedures. Spectrophotometry was used to assess levels of DNPH, MDA, NO, and ONOO-. CRP levels were evaluated using an immunoturbidimetric assay. The patients under 37 years with normal ovarian reserve had significantly lower levels of MDA, DNPH, NO, ONOO-, and CRP compared to those over 37 years. Additionally, we observed higher levels of MDA, DNPH, NO, ONOO-, and CRP in the group with an oocyte maturity rate of less than 60%. No significant difference was observed between the DNPH levels and factors such as infertility duration, embryo quality, pregnancy, or the number of retrieved oocytes. A higher level of MDA, NO, ONOO-, and CRP was found to be significantly related to the lower number of retrieved oocytes, longer periods of infertility, poor embryo quality, and negative pregnancy outcomes. Oxidative/nitrosative stress, linking to inflammation in the oocyte microenvironment, can be considered as a potentially useful biomarker for assessing the development and competence of oocytes and embryos and predicting ICSI outcomes.

Association of Methylenetetrahydrofolate Reductase Gene Polymorphism C677T with Oocyte Number and Embryo Quality in Iraqi Infertile Women Undergoing Intracytoplasmic Sperm Injection

Background: Methylenetetrahydrofolate reductase (MTHFR) C677T is a single nucleotide polymorphism (SNP) that affects the production of 5-methyltetrahydrofolate (5-MTHF), the active folate that enables the recycling of homocysteine (Hcy) to methionine. Objective: to investigate the association between the MTHFR (C677T) polymorphism and the outcomes of intracytoplasmic sperm injection (ICSI). Methods: A prospective cohort study included 85 infertile women undergoing ICSI treatment at the High Institute of Infertility Diagnosis and Assisted Reproductive Technologies in Baghdad, Iraq. The study period extended from January 2022 to September 2023. The MTHFR C677T polymorphism genotyping was evaluated in these patients, and they were classified into three groups according to genotyping results: normal (CC), heterozygote mutated (CT), and mutated homozygote (TT). In addition, we conducted a comparative analysis of oocyte, embryo and pregnancy rates among these three groups. Results: In comparison to the CT and TT genotypes, the total number of oocytes, total embryos, mature oocytes, good-quality embryos, and pregnancy rate were all found to be significantly higher (p&lt;0.05) in the CC genotype. Compared to the CC group, the proportion of immature oocytes and poor-quality embryos was significantly higher in the TT and CT groups (p&lt;0.05). The rate of fertilization was comparable among the study groups. Conclusions: The maternal MTHFR C677T polymorphism is linked to oocyte number, maturity, total embryo, embryo quality, and pregnancy in ICSI. In light of this, MTHFR polymorphism in our community offers useful data regarding the success of ICSI.

Impaired embryo development potential associated with thyroid autoimmunity in euthyroid infertile women with diminished ovarian reserve.

The aim of this study was to evaluate the associations of thyroid autoimmunity (TAI) with the number of oocytes retrieved (NOR), fertilization rate (FR), and embryo quality (EQ) in euthyroid women with infertility and diminished ovarian reserve (DOR). This retrospective cohort study involved 1,172 euthyroid women aged 20-40 years with infertility and DOR who underwent an oocyte retrieval cycle. TAI was diagnosed in the presence of serum thyroperoxidase antibody (TPOAb) concentrations higher than 34 IU/ml and/or serum thyroglobulin antibody (TgAb) concentrations exceeding 115.0 IU/ml. Among these women, 147 patients with TAI were classified as the TAI-positive group, while 1,025 patients without TAI were classified as the TAI-negative group. Using generalized linear models (GLMs) adjusted for confounding factors, we evaluated the associations of TAI and the serum TPOAb and TgAb concentrations and NOR, FR, and EQ in this study's subjects. The TPOAb and TGAb values were subjected to log10 transformation to reduce skewness. Logistic regression models were used to estimate the effects of TPOAb and TgAb concentrations on the probabilities of achieving a high NOR (≥7) and high FR (>60%). For the whole study population, women with TAI had a significantly lower NOR and poorer EQ than women without TAI (P < 0.001 for both). Interestingly, in the TSH ≤2.5 subgroup, the TAI-positive group also had a significantly lower NOR and poorer EQ than the TAI-negative group (P < 0.001 for both). Furthermore, negative associations were observed between log10(TPOAb) concentrations and NOR and the number of high-quality embryos and available embryos (P < 0.05 for all). The log10(TgAb) concentrations were inversely associated with NOR and the number of high-quality embryos (P < 0.05 for all). In the regression analysis, the log10(TPOAb) concentrations had lower probabilities of achieving a high NOR [adjusted odds ratio (aOR): 0.56; 95% confidence interval (95% CI) 0.37, 0.85; P = 0.007]. TAI and higher TPOAb and TgAb concentrations were shown to be associated with reductions in the NOR and EQ in the study population. Our findings provide further evidence to support systematic screening and treatment for TAI in euthyroid women with infertility and DOR.

#328 : Fertilization and Embryo Quality of Human Mature Oocytes with Morphological Abnormalities After Intracytoplasmic Sperm Injection (ICSI)

Background and Aims: The dysmorphism of oocytes either extra or intracytoplasmic could decrease viability and developmental competence of oocytes. There are several reports describing that specific dysmorphisms are related with decrease in fertilization and embryo competence. The aim of this research is to investigate fertilization and embryo quality of specific dysmorphic mature oocytes obtained from ICSI. Method: A retrospective analysis was performed in 183 patients with 1700 mature oocytes. Mature oocytes were classified as normal morphology (control), oocytes with intra-cytoplasmic dysmorphism (fragile oocytes, inclusion bodies, vacuoles, mild granularity of cytoplasm, severe granularity of cytoplasm, and central granulation), and oocytes with extra-cytoplasmic dysmorphism (granulation in perivitelline space, polar body fragmentation, large perivitelline space, and abnormal zona pellucida). All oocytes were inseminated with ICSI. Oocytes were cultured and scored on day 3 then some of them were transferred. The rest of oocytes were extended culture until day 5. Day 3 embryos were classified based on grading by Kamardi et al., 2021. Grade 1 and 2 embryos are considered good quality embryos. Day 5 embryos were classified based on modified grading by Gardner and Schoolcraft., 1999. Results: Overall, fertilization rate was significantly lower in the dysmorphic oocytes compared to control (P&lt;0.01). Good quality embryo development on day 3 was significantly lower in oocytes with severe granularity of cytoplasm compared to control (P&lt;0.05). Looking at embryo development on day 5, oocytes with inclusion bodies and central granulation had significantly lower on good quality blastocyst (P&lt;0.05). Conclusion: The fertilization potential of dysmorphic oocytes in our study was lower compared to normal morphology oocytes, however, only severe granularity of cytoplasm, inclusion bodies and central granulation related with poor embryo quality on day 3 and day 5. In this study, we were able to define several specific of oocyte dimorphism related with lower fertilization and embryo quality.

#289 : Mitochondrial Activator BGP-15 Protects Sperm from DNA Damage During Sperm Recovery for Assisted Reproductive Technology

Background and Aims: The recovery of sperm by assisted reproductive technology (ART) results in significant DNA damage. Elevated levels of DNA damage in sperm have been linked to poor-quality embryos and increased pregnancy loss after ART. Therefore, in this study, we aimed to investigate potential of the new mitochondrial activator BGP-15 to prevent sperm DNA damage in an in vitroejaculate over time. Additionally, we sought to determine whether BGP-15 can preserve sperm quality during various sperm recovery techniques used in ART. Method: We incubated donated human semen specimens untreated or treated with BGP-15, then examined sperm motility and DNA damage (DNA fragmentation and oxidation). Semen samples were then processed using different clinical sperm recovery methods: simple wash (SW), swim-up (SU) and density gradient centrifugation (DGC); and the purified sperm underwent further analysis including motility, vitality, ROS levels, mitochondrial membrane integrity and mitochondrial membrane potential (MMP), and DNA damage. Results: Semen samples incubated with BGP-15 demonstrated improved sperm motility and reduced DNA damage levels. SW samples had the highest sperm count, while SU had the highest vitality and DNA integrity, but the lowest MMP. DGC sperm had increased MMP after BGP-15 Treatment. Although BGP-15 treatment only reduced sperm DNA fragmentation in SW samples, it reduced DNA oxidation in all recovery methods. Conclusion: Our findings indicate that clinical manipulation of patient semen samples can negatively impact sperm quality, and different sperm recovery methods have unique effects. However, the addition of BGP-15 to clinical processes can preserve sperm quality, potentially leading to improved embryo quality and ART success.

#142 : “No Result” Embryos After PGTA: Should They Be Disposed?

Background and Aims: Sometimes the preimplantation genetic testing for aneuploidy (PGTA) results return with “no result” (NR) even though the percentage of this type of result is quite small. Our desire was to rebiopsy these embryos and reanalysis, then determining whether it is efficient to perform reanalysis in “no result” embryos with different embryo qualities and evaluating the efficacy of rebiopsied blastocyst transfers. Materials and Methods: Performing trophectoderm rebiopsy for inconclusive blastocysts after PGTA test. The blastocysts would be transferred if the second analysis was eligible. Results: From September 2020 through December 2022, 2838 embryos were biopsied and tested for PGTA, 95 samples were returned as “no result”, accounting for 3.3%. There was no difference between the embryo quality grades in NR embryos (p&gt;0.05), but the NR day 5 embryos was statistically higher than the group of day 6 embryos (85.3% vs 14.7%, p&lt;0.05). The rate of ICM grade A was significantly higher than the rate of ICM grade C (42.1% vs 23.2%, p&lt;0.05). However, TE grade B group was significantly higher than the group of TE grade A and TE group C. We performed re-biopsy and repeated PGTA test for 67 eligible embryos, 66/67 (98.5%) samples had results. The euploid rate after the second analysis was 46.3%. 16 euploid cases were transferred after the second analysis, the warming survival rate was 100% and the ongoing pregnancy rate was 56.3% (9/16) and there were 7 live births. The ongoing pregnancy rate in the group of good blastocyst grade (grade 1, 2) was higher than those in the group of poor blastocyst grade (grade 3) (44.4% vs 11.2%, respectively). Conclusions: Performing re-biopsy and repeat PGTA testing can reduce the risk of embryo wastage, increasing the chance of embryo transfer for patients indicated for PGTA. However, in cases of poor-quality embryo re-biopsy, the pregnancy rate after embryo transfer is very low even though the biopsy result is euploid. Therefore, it is necessary to weigh the benefits and risks of rebiopsy in cases where embryo quality is not eligible to optimize efficiency of time and cost for the patients.

Original delayed-start ovarian stimulation protocol with a gonadotropin-releasing hormone antagonist, medroxyprogesterone acetate, and high-dose gonadotropin for poor responders and patients with poor-quality embryos.

The delayed-start gonadotropin-releasing hormone antagonist protocol seems effective for patients who are poor ovarian responders, but there are insufficient data on whether it is also effective for patients with poor-quality embryos and low rates of good blastocyst formation. Specifically, the effectiveness of delayed-start gonadotropin-releasing hormone antagonists with progesterone has not been adequately investigated. Therefore, we compared the efficacy of the original delayed-start gonadotropin-releasing hormone antagonist protocol using medroxyprogesterone acetate (MPA) and high-dose gonadotropin in patients with poor ovarian response. Overall, 156 patients with recurrent assisted reproductive technology failure who underwent the original protocol were included. They received cetrorelix acetate (3 mg) and MPA (10 mg) on cycle day 3, and high-dose gonadotropin was initiated on day 11. When the leading follicle reached 14mm, ganirelix acetate (0.25 mg) was administered until the trigger day. The number of oocytes retrieved, metaphase II (MII) oocytes, two pronuclear (2PN) zygotes, and good blastocysts and live birth rates were compared between the previous (Cycle A) and original (Cycle B) cycles in three groups (Group A, all patients; Group B, poor responders; and Group C, patients with poor-quality embryos). In Group A (n=156), the number of MII oocytes (3.6 ± 3.3 versus 4.5 ± 3.6), 2PN zygotes (2.8 ± 2.9 versus 3.8 ± 3.1), good blastocysts (0.5 ± 0.9 versus 1.2 ± 1.6), and live birth rates (0.6 versus 24.4) significantly increased in Cycle B. Similar results were obtained in Group B (n=83; 2PN zygotes [1.7 ± 1.7 versus 2.3 ± 1.8], good blastocysts [0.4 ± 0.7 versus 0.9 ± 1.3], live birth rates [0 versus 18.1]) and Group C (n=73; MII oocytes [5.1 ± 3.8 versus 6.6 ± 4.0], 2PN zygotes [4.0 ± 3.4 versus 5.4 ± 3.4], good blastocysts [0.7 ± 1.1 versus 1.6 ± 1.9], and live birth rates [1.4 versus 31.5]). This original protocol increased the number of MII oocytes retrieved, 2PN zygotes, good blastocysts, and live birth rates in both poor responders and in patients with poor-quality embryos.

The following article for this Special Issue was published in a different issue. They can be found in their respective issue.

Increased sperm deoxyribonucleic acid damage leads to poor embryo quality and subfertility of male rats treated with methylphenidate hydrochloride in adolescence. ANDR. 2022; 10(8): 1632-1643. https://doi.org/10.1111/andr.13277.

Evaluation of Clinical Outcomes after Poor-Quality Embryo Transfer and Prognostic Parameters.

We aimed to investigate the clinical results following poor-quality embryo transfer and the parameters to foresee the prognosis. In this study, 2123 cycles that had day 3 and day 5 single-fresh embryo with poor-quality embryo transfers and good-quality embryo transfers were compared. The cycles according to transfer day were evaluated by conducting a subgroup analysis. The correlation between all the obtained demographic characteristics, controlled ovarian stimulation parameters, and cycle results were analysed. Clinical pregnancy was established in 53 patients that underwent transfer in the poor-quality embryo group (14.9%). Of these patients, 36 had live birth (live birth rate per clinical pregnancy 67.9%). In cleavage-stage embryos, live birth rates per clinical pregnancy were higher in poor-quality blastocyst transfer. When analysing the factors affecting live births in the poor-quality embryo group, as the total gonadotropin dose increases, the probability of live birth decreases, as in the probability of hCG positivity. In conclusion, although the probability of pregnancy is low, when clinical pregnancy is established, there is a high chance of having a live birth after poor-quality embryo transfers. This could be regarded as an acceptable option in cycles when only poor-quality embryos are available.

Effects of embryo characteristics in frozen-thawed single euploid blastocyst transfers on pregnancy outcomes: a retrospective cohort study

Objectives: Our study examined the effects of the trophectoderm biopsy (TB) day and the presence of necrotic foci (NF) or separate blastomeres (SB) within euploid embryos on in vitro fertilization (IVF) pregnancy outcomes. Methods: This retrospective cohort study was conducted from January 2017 to September 2021 at Memorial Sisli Hospital, Istanbul, Turkey. The study comprised a total of 2758 frozen-thawed euploid embryo transfer cycles. After thawing, blastocysts were graded using Gardner's classification Top-Quality (TQ), Good-Quality (GQ), Moderate-Quality (MQ), Poor-Quality (PQ) and further divided into groups according to the presence of NF and/or SB and evaluated for pregnancy outcomes. Results: There were significant correlations between pregnancy outcomes and the degree of blastocoele expansion, as well as the presence of NF or SB in the euploid embryo. Ongoing pregnancy rates were lower in the group with NF in the inner cell mass (ICM) or trophectoderm (TE) than in the group without NF. The presence of SB decreased the rates of ongoing pregnancy and increased the rates of miscarriage. Embryos with expansion grades ≤ 3 had lower rates of ongoing pregnancy and higher rates of miscarriage compared to embryos with expansion grades&amp;gt; 3. TQ and GQ embryos had a higher rate of ongoing pregnancy and a lower rate of miscarriage than MQ and PQ embryos. Conclusions: When selecting the embryo to be transferred to a patient, careful consideration should be given to the morphological grade of the embryo as well as whether or not it contains NF and SB.

Interpretable artificial intelligence-assisted embryo selection improved single-blastocyst transfer outcomes: a prospective cohort study

Research questionWhat is the pregnancy and neonatal outcomes of an interpretable artificial intelligence (AI) model for embryo selection in a prospective clinical trial? DesignThis single-centre prospective cohort study was carried out from October 2021 to March 2022. A total of 330 eligible patients were assigned to their preferred groups, with 250 patients undergoing a fresh single-blastocyst transfer cycle after the exclusion criteria had been applied. For the AI-assisted group (AAG), embryologists selected the embryos for transfer based on the ranking recommendations provided by an interpretable AI system, while with the manual group, embryologists used the Gardner grading system to make their decisions. ResultsThe implantation rate was significantly higher in the AAG than the manual group (80.87% versus 68.15%, P = 0.022). No significant difference was found in terms of monozygotic twin rate, miscarriage rate, live birth rate and ectopic pregnancy rate between the groups. Furthermore, there was no significant difference in terms of neonatal outcomes, including gestational weeks, premature birth rate, birth height, birthweight, sex ratio at birth and newborn malformation rate. The consensus rate between the AI and retrospective analysis by the embryologists was significantly higher for good-quality embryos (i.e. grade 4BB or higher) versus poor-quality embryos (i.e. less than 4BB) (84.71% versus 25%, P < 0.001). ConclusionsThese prospective trial results suggest that the proposed AI system could effectively help embryologists to improve the implantation rate with single-blastocyst transfer compared with traditional manual evaluation methods.

Current Insights in the Repeat Breeder Cow Syndrome.

Cows can have difficulties becoming pregnant, and in certain cases, these reproductive failures do not have an evident cause. Furthermore, when these failures are repeated three or more times with estrous cycles of normal duration and in the absence of evident clinical signs, it is considered repeat breeder cow (RBC) syndrome. A substantive incidence of RBC syndrome has been reported all over the world, which severely affects the farm economy. This paper reviews those studies particularly focused on RBC syndrome from 2000 to 2023 but also includes consolidated information until this date. Hormonal imbalances, undetectable oviductal or uterine defects, or poor oocyte or embryo quality have been reported as causes of RBC syndrome, while subclinical endometritis has been considered a relevant causal agent. However, it is unresolved why this condition is recurrent in certain animals, despite the implementation of corrective management actions or treatments. Recent studies evaluate the putative role of certain genes, factors, hormones, or proteins in the pathogenesis of RBC syndrome. Numerous risk factors contribute to the appearance of this syndrome, and some of them could be mitigated to partially prevent this infertility, while others cannot be changed. Due to the complexity of this syndrome, it is important to increase knowledge about the mechanisms involved, develop new diagnostic tools to differentiate causal agents, and implement new treatments to restore fertility. There is consensus about the huge repercussions of this syndrome on farm profitability, but further studies are now needed to describe its economic impact.

Should ICSI be implemented on patients with poor-quality embryos in the previous IVF cycle?

This study was to evaluate whether Intracytoplasmic sperm injection (ICSI) can improve the quality of embryo in patients with poor-quality embryos in the previous In-vitro fertilization (IVF) cycle, which was cancelled before transfer. This was a retrospective cohort study of 178 IVF and 158 ICSI cycles for patients with poor-quality embryos in the previous IVF cycle in the Center for Reproductive Medicine, Women and Children's Hospital of Chongqing Medical University from March 2016 to June 2022. The 2 PN rate, oocyte utilization rate , high-quality embryo rate and clinical pregnancy rate were compared between the two groups. Furthermore, the implantation rate, miscarriage rate and cycle cancelation rate were measured and compared. ICSI resulted in a comparable 2 PN rate, oocyte utilization rate and cycle cancelation rate with IVF. The high-quality embryo rate of ICSI group was significantly higher than that of IVF group (5.56% vs. 2.60%, P < 0.05). Eventually, a total of 239 patients performed embryo transfer. ICSI resulted in a significantly higher clinical pregnancy rate (55.56% vs. 40.98%, P < 0.05) compared with IVF, however, there were no notable differences in miscarriage rate and implantation rate. The present study suggested that ICSI significantly improved the high-quality embryo rate and clinical pregnancy of the patients with poor-quality embryos in the previous IVF cycle. Prospective randomized controlled trials are needed to further verify.

Pre-Implantation Bovine Embryo Evaluation—From Optics to Omics and Beyond

Approximately 80% of the ~1.5 million bovine embryos transferred in 2021 were in vitro produced. However, only ~27% of the transferred IVP embryos will result in live births. The ~73% pregnancy failures are partly due to transferring poor-quality embryos, a result of erroneous stereomicroscopy-based morphological evaluation, the current method of choice for pre-transfer embryo evaluation. Numerous microscopic (e.g., differential interference contrast, electron, fluorescent, time-lapse, and artificial-intelligence-based microscopy) and non-microscopic (e.g., genomics, transcriptomics, epigenomics, proteomics, metabolomics, and nuclear magnetic resonance) methodologies have been tested to find an embryo evaluation technique that is superior to morphologic evaluation. Many of these research tools can accurately determine embryo quality/viability; however, most are invasive, expensive, laborious, technically sophisticated, and/or time-consuming, making them futile in the context of in-field embryo evaluation. However accurate they may be, using complex methods, such as RNA sequencing, SNP chips, mass spectrometry, and multiphoton microscopy, at thousands of embryo production/collection facilities is impractical. Therefore, future research is warranted to innovate field-friendly, simple benchtop tests using findings already available, particularly from omics-based research methodologies. Time-lapse monitoring and artificial-intelligence-based automated image analysis also have the potential for accurate embryo evaluation; however, further research is warranted to innovate economically feasible options for in-field applications.

P-165 Artificial removal of the zona pellucida at the pronuclear stage in patients with poor quality embryos with severe fragmentation

Abstract Study question Is artificial removal of the zona pellucida (ZP) at the pronuclear stage effective in patients with poor quality embryos with severe fragmentation? Summary answer Artificial removal of the ZP at the pronuclear stage significantly improved culture results in patients with poor quality embryos with severe fragmentation. What is known already In 2020, Yumoto et al. first reported that artificial removal of the ZP (ZP-free) at the pronuclear stage decreased the rate of fragmentation and improved the culture outcomes of 3 pronuclei (3PN) embryos reaching to the good blastocysts. Therefore, the ZP may not always be necessary for normal embryonic development after the pronuclear stage. The same group presented at the 37th ESHRE meeting in 2021, that the blastocyst transfer after ZP-free embryo of 2 pronuclei (2PN) resulted in normal pregnancy in two patients with poor-quality embryos resulting in live births. Study design, size, duration This study included 211 of 2PN embryos from 46 cycles for 30 couples obtained between July 2021 and December 2022, whose previous oocyte retrieval cycle showed massive cytoplasmic fragmentation at the first cleavage confirmed by a time-laps incubator (TLI). Average age of women was 38.8years. The embryos with artificial removal of the ZP at the pronuclear stage were cultured in a TLI up to 7 days. All blastocysts were cryopreserved for future embryo transfer cycles. Participants/materials, setting, methods All participants provided written informed consent, and Institutional Review Board approval was obtained. Artificial removal of the ZP at the pronuclear stage was performed by following procedure. 1) Embryos were placed in 0.125M sucrose-containing HEPES for cytoplasm shrinking. 2) The ZP without adhesion was removed with a laser system. 3) Ooplasms were completely separated from ZP by blowing the medium to adhesion point like a jet car wash. 4) ZP-free embryo was obtained. Main results and the role of chance Day 3 embryos were divided into 3 groups using the Veeck’s classification: 8 cell embryos with grade 2 or higher were defined as good, embryos with grade 4 or 5 regardless of the number of cells were defined as poor, and others were defined as fair. We compared the culture results of ZP-free cycle and previous oocyte retrieval cycle (ZP-intact). For day 3 embryos, good, fair and poor grade were 19.4% (41/211), 62.6% (132/211) and 18.0% (38/211) in ZP-free embryos compared with 2.9% (15/561), 37.4% (210/561), and 59.9% (336/561) in the past, respectively (p &amp;lt; 0.001). Good-quality blastocysts were defined as 3BB or more on day 5 by the Gardner’s classification. As to the blastocysts, blastocysts development and good-quality blastocysts rates were 45.0% (95/211) and 27.0% (57/211) in ZP-free embryos compared with 23.0% (112/488) and 6.8% (33/488) in the past, respectively (p &amp;lt; 0.001). Of these, 30 embryo transfers were performed resulting in 11 clinical pregnancies. We had 3 live births without any congenital anomalies and one miscarriage. One was delivered at 33 weeks of gestation with caesarian section, one mother had gestational diabetes. Limitations, reasons for caution This study was retrospective study without any control group and was conducted at only single fertility center. It is necessary to conduct sibling oocytes study to demonstrate the effectiveness of ZP-free culture, and to create criteria who are benefit from ZP-free culture. Moreover, safety of ZP-free culture should be evaluated. Wider implications of the findings ZP-free culture reduced fragments and improved culture outcomes in patients with poor quality embryos with severe fragmentation. ZP-free culture might bring light to the patients who have difficulty obtaining good-quality embryos with severe fragmentation. Trial registration number Not Applicable