Preimplantation Genetic Diagnosis Research Articles

Impact of double trophectoderm biopsy on reproductive outcomes following single euploid blastocyst transfer

ObjectivesTo study the effect of double trophectoderm biopsy on clinical outcomes following single euploid blastocyst transfer. Study designRetrospective cohort study of 2046 single euploid frozen-thawed blastocyst transfers from January 2015 to June 2022 in a single centre.All patients undergoing a frozen-thawed embryo transfer (FTET) cycle with euploid blastocysts, biopsied for any indication, were included. The outcomes were compared for blastocysts which were biopsied and vitrified once (Group 1, n = 1684), biopsied once but vitrified twice (Group 2, n = 312) and biopsied and vitrified twice (Group 3n = 50). We adjusted for confounders and performed subgroup analysis for PGT-A, PGT-M and PGT-SR cycles. The primary outcome was live birth rate. Secondary outcomes included pregnancy, clinical pregnancy, birthweight and sex ratio. ResultsAfter adjusting for confounders (previous failed euploid implantations, embryo quality and day of biopsy), embryos which were biopsied twice had lower OR for clinical pregnancy (0.48, CI 0.26–0.88, p = 0.019) and for live birth (0.50 CI 0.27–0.92, p = 0.025) compared to controls. Embryos which were biopsied once but vitrified twice had no different ORs for all reproductive outcomes compared to controls. No significant difference was observed for neonatal birthweight or sex ratio amongst the three groups. This is a retrospective single centre study with inherent bias and results may not be transferable to all settings. ConclusionThis study is the largest to date assessing the outcomes of FTET cycles following double trophectoderm biopsy. The results are in keeping with the existing literature and can be incorporated into patient counselling. Whilst double biopsy seems to adversely impact LBR, it is only one of the many factors that can affect success rates. The subfertility background and embryo characteristics should not be overlooked. This study provides reassuring evidence since double biopsied embryos still result in live births with no difference in sex ratio or birthweight. However, long term follow up of the off-springs is lacking and should be reported in future studies.

Preimplantation diagnosis and embryo selection in a patient with severe hereditary coproporphyria

Preimplantation diagnosis and embryo selection in a patient with severe hereditary coproporphyria

Ovarian reserve in patients with FMR1 gene premutation and the role of fertility preservation

Ovarian reserve in patients with FMR1 gene premutation and the role of fertility preservation

The impact of a second embryo biopsy for preimplantation genetic testing for monogenic diseases (PGT-M) with inconclusive results on pregnancy potential: results from a matched case-control study.

To evaluate whether a second biopsy, following a first diagnostic failure on blastocysts tested for preimplantation genetic testing for monogenic diseases (PGT-M), allows to obtain genetic diagnosis and to what extent this procedure can influence clinical pregnancy and live birth rates compared to the PGT-M process with a successful genetic diagnosis from the first biopsy. Embryos from women who underwent PGT-M in an infertility centre and who had been transferred after two biopsies for genetic analysis (n = 27) were matched in a 1:1 ratio accordingly to women's age (± 1year) and fertility status (fertilevsinfertile), as well as with the study period, with embryos who were transferred after receiving a conclusive PGT result straight after the first biopsy (n = 27). The main evaluated outcome was clinical pregnancy rate following embryo transfers in which healthy embryos were transferred after only one biopsy and those in which an embryo was transferred after being re-biopsied. Live birth rate was the secondary outcome. Clinical pregnancy rate was 52% (95% CI: 34-69) following the transfer of a single-biopsy blastocyst and 30% (95% CI: 16-48) following the transfer of a re-biopsied blastocyst. The likelihood to have a healthy baby was 33% (95% CI: 19-52) following the transfer of a blastocyst biopsied once and 22% (95% CI: 11-41) following the transfer of a re-biopsied blastocyst. The re-biopsy intervention seems to considerably reduce the pregnancy potential of a blastocyst. However, a greater sample size is necessary to clarify this issue definitively.

Genotype-phenotype correlation and mutation spectrum of HBB gene in the Hatay province of Turkey

Purpose: Thalassemia carriage and hemoglobinopathies are quite common disorders in Turkey, especially in the Çukurova region, including Hatay province. Due to the high case population and genetic diversity in our region, this study aimed to investigate the genotype-phenotype correlation in the HBB gene.
 Materials and Methods: The data of patients who applied to Hatay Mustafa Kemal University Medical Genetics or Hematology Clinic between January 2010 and November 2022 were evaluated retrospectively.
 Results: A total of 40 (100%) cases, comprising 25 (62.5%) homozygous and 15 (37.5%) compound heterozygous genotypes, were included in the study based on the mutation profiles in the HBB gene. In the analysis of the cases, it was seen that there were 17 different variants and 22 distinct genotypes. The three most common variants identified in this study were IVS-I-6 (T>C), IVS-I-1 (G>A), and IVS-II-848 (C>A). Of the cases with homozygous genotypes, 13 (52%) had the IVS-I-6 (T>C) variant. The most frequent genotypes observed in cases with compound heterozygous genotype were IVS-I-6 (T>C)/IVS-I-110 (G>A), IVS-I-6 (T>C)/Hb Knossos, and IVS-I-110 (G>A)/-101 C>T, each in 2 (13%) cases.
 Conclusion: This study provides information on the phenotypic characteristics of very rare genotypes. We think that this information will be very beneficial, especially for clinicians interested in prenatal diagnosis, preimplantation genetic diagnosis, and postnatal genetic counseling.

Assessment of the implantation window and embryonic factor impact to the treatment of recurrent implantation failure (RIF). A prospective study

The aim: to study of the prognostic value of endometrial receptivity and preimplantation genetic diagnosis of embryos, and their influence on the effectiveness of in vitro fertilization (IVF) programs. We also evaluate the importance of this factor in comparison with other potential causes of infertility. Materials and methods: This prospective cohort study included 123 infertile women who underwent in vitro fertilization (IVF) treatment. 93 patients had repeated unsuccessful implantation attempts and were divided into three groups: group 1 - patients who were treated using genetically untested embryos according to a standard fixed stimulation protocol, group 2 - patients who were treated using euploid embryos after preimplantation genetic screening according to standard fixed protocol; group 3 - patients who underwent treatment using euploid embryos after pre-implantation genetic screening and determination of the implantation window with subsequent modification of the stimulation protocol, according to the endometrial examination result. 30 patients had a first attempt at IVF, which was carried out using genetically untested embryos, according to a standard fixed protocol, and made up the control group (CG). Determination of the window of implantation was carried out by triple aspiration biopsy of the endometrium during the luteal phase of the menstrual cycle since the endometrium is most susceptible to implantation during this period. Samples were analyzed using scanning electron microscopy. Based on the results obtained, the endometrial preparation protocol was individualized for the next attempt. preimplantation genetic testing (PGT) of embryos was carried out by the next generation (NGS) method. Statistical analysis was performed using IBM SPSS V25.0 for Windows software. Results: According to the obtained results, patient characteristics, screening rates, IVF cycle characteristics, and the number, quality, and stage of transferred embryos were compared between groups. The rate of clinical pregnancy was 46.7 % among patients of group 1.70 % among patients of group 2, 82.8 % among patients of group 3 and 50.0 % of the control group and statistically significantly different between groups (χ2=10.955, p= 0.012). The rate of live birth was 43.3 % among patients of group 1, 53.3 % among patients of group 2, 72.4 % among patients of group 3 and 43.3 % - of the control group, however, it did not differ statistically significantly between groups (χ2=6,639, р=0,084) Conclusions: The unique window of implantation and the embryonic factor are among the main reasons for multiple failed implantation attempts. Personalization of the endometrial preparation protocol and preimplantation embryo diagnosis are effective methods to improve IVF outcomes

Molecular autopsy for fetal structural anomaly: diagnostic and clinical utility of multidisciplinary team approach.

In the West Midlands Regional Genetic Service, cases of perinatal death with a possible genetic diagnosis are evaluated by the Perinatal Pathology Genetic Multidisciplinary Team (MDT). The MDT assessed autopsy findings and considered genomic assessments. The objective of this retrospective service evaluation was to determine the clinical utility of the MDT. This is the first evaluation since the introduction of whole genome and whole exome sequencing in routine clinical care. The outcomes for all the perinatal MDT cases from January 2021 to December 2021 were examined. All cases received a full or partial post-mortem examination (PM) and a chromosomal microarray. Demographics, phenotype, MDT recommendations, genetic testing, diagnoses, outcomes, impact of PM and impact of genetic testing were collected from patient case notes. One hundred and twenty-three cases were discussed at the MDT meeting in 2021. Genetic evaluation was recommended in 84 cases and accepted in 64 cases. A range of genetic tests were requested according to indication and availability. Thirty diagnoses were identified in 29 cases from 26 unrelated families. The diagnostic yield was 24% (29/123) of all cases or 45% (29/64) of the cases with a suspected genetic diagnosis who underwent genetic testing. PM examination added clinically actionable phenotype data in 79% of cases. A genetic diagnosis enabled accurate counselling of recurrence risk and provision of appropriate follow-up, including prenatal testing and preimplantation diagnosis for patients with inherited conditions. Genomic testing was a clinically useful addition to (but not a substitute for) PM examination in perinatal cases associated with structural anomalies. The MDT model helped assess cases and plan appropriate follow-up. Expedited whole genome sequencing or panel-agnostic analysis were most appropriate for heterogeneous presentations. This broad approach can also expand prenatal phenotypes and detect novel disease genes and should be a priority for future research. This article is protected by copyright. All rights reserved.

Evaluating the Plausibility of Euploid Embryos Transfer on Day-5 by Reanalysis of Day-3 Single Aneuploid Embryos: A Case Series

Background: During preimplantation development, single aneuploidies are more commonly tolerated than complex aneuploidies. Some studies have reported that blastocysts with aneuploid karyotypes on Day-3 embryo biopsy can exhibit a normal karyotype on Day-5 rebiopsy, suggesting that single aneuploidies may have a higher likelihood of presenting a normal karyotype on Day-5. The purpose of the current study was to assess the benefit of reanalyzing the karyotypes of Day-3 single aneuploid embryos on Day-5.
 Methods: Day-3 and Day-5 biopsies of preimplantation embryos were subjected to array comparative genomic hybridization (aCGH). A proof of concept case series study was conducted involving 13 Day-5 embryos from 4 couples across 3 ART centers, collected between October 2019 and June 2020. Each center provided one normal embryo and 3-4 embryos with single aneuploidy based on Day-3 aCGH results. The karyotype of each Day-5 embryo was compared with its corresponding Day-3 karyotype.
 Results: Among the 10 embryos with single aneuploidy on Day-3, 3 (30%) exhibited discordant karyotypes on Day-5, while the remaining 7 single aneuploid embryos and 3 normal embryos maintained the same karyotype from Day-3 to Day-5. None of the Day-3 single aneuploid embryos displayed a normal karyotype on Day-5.
 Conclusion: Contrary to previous reports suggesting the potential correction of single aneuploidies in some embryos, the findings of this study did not support such a possibility in the analyzed embryos. Genomic reanalysis of Day-3 single aneuploid embryos on Day-5 does not appear to be a reliable method for identifying euploid embryos suitable for transfer.

Public Reason, Bioethics, and Public Policy: A Seductive Delusion or Ambitious Aspiration?

Can Rawlsian public reason sufficiently justify public policies that regulate or restrain controversial medical and technological interventions in bioethics (and the broader social world), such as abortion, physician aid-in-dying, CRISPER-cas9 gene editing of embryos, surrogate mothers, pre-implantation genetic diagnosis of eight-cell embryos, and so on? The first part of this essay briefly explicates the central concepts that define Rawlsian political liberalism. The latter half of this essay then demonstrates how a commitment to Rawlsian public reason can ameliorate (not completely resolve) many of the policy disagreements related to bioethically controversial medical interventions today. The goal of public reason is to reduce the size of the disagreement by eliminating features of the disagreement that violate the norms of public reason. The norms of public reason are those norms that are politically necessary to preserve the liberal, pluralistic, democratic character of this society. What remains is reasonable disagreement to be addressed through normal democratic deliberative processes. Specific issues addressed from a public reason perspective include personal responsibility for excessive health costs, the utility of a metaphysical definition of death for organ transplantation, and the moral status of excess embryos generated through IVF and/or their use in medical research.

Appropriate whole genome amplification and pathogenic loci detection can improve the accuracy of preimplantation genetic diagnosis for deletional α-thalassemia.

To improve the accuracy of preimplantation genetic testing (PGT) in deletional α-thalassemia patients. Article. fifty-two deletional α-thalassemia couples. Whole genome amplification (WGA), Next-generation sequencing (NGS) and PCR mutation loci detection. WGA, Single nucleotide polymorphism (SNP) and PCR mutation loci detection results; Analysis of embryo chromosome copy number variation (CNV). Multiple Displacement Amplification (MDA) and Multiple Annealing and Looping-Based Amplification Cycles (MALBAC) methods for PGT for deletional α-thalassemia. Blastocyst biopsy samples (n = 253) were obtained from 52 deletional α-thalassemia couples. The results of the comparison of experimental data between groups MALBAC and MDA are as follows: (i) The average allele drop-out (ADO) rate, MALBAC vs. MDA = 2.27% ± 3.57% vs. 0.97% ± 1.4%, P=0.451); (ii) WGA success rate, MALBAC vs. MDA = 98.61% vs. 98.89%, P=0.851; (iii) SNP haplotype success rate, MALBAC vs. MDA = 94.44% vs. 96.68%, P=0.409; (iv) The result of SNP haplotype analysis is consistent with that of Gap-PCR/Sanger sequencing results, MALBAC vs. MDA = 36(36/72, 50%) vs. 151(151/181, 83.43%), P=0; (v) Valid SNP loci, MALBAC vs. MDA = 30 ± 9 vs. 34 ± 10, P=0.02; (vi) The mean CV values, MALBAC vs. MDA = 0.12 ± 0.263 vs. 0.09 ± 0.40, P=0.916; (vii) The average number of raw reads, MALBAC vs. MDA =3244259 ± 999124 vs. 3713146 ± 1028721, P=0; (viii) The coverage of genome (%), MALBAC vs. MDA = 5.02 ± 1.09 vs. 5.55 ± 1.49, P=0.008. Our findings indicate that MDA is superior to MALBAC for PGT of deletional α-thalassemia. Furthermore, SNP haplotype analysis combined with PCR loci detection can improve the accuracy and detection rate of deletional α-thalassemia.

Mapping crossover events of mouse meiotic recombination by restriction fragment ligation-based Refresh-seq

Single-cell whole-genome sequencing methods have undergone great improvements over the past decade. However, allele dropout, which means the inability to detect both alleles simultaneously in an individual diploid cell, largely restricts the application of these methods particularly for medical applications. Here, we develop a new single-cell whole-genome sequencing method based on third-generation sequencing (TGS) platform named Refresh-seq (restriction fragment ligation-based genome amplification and TGS). It is based on restriction endonuclease cutting and ligation strategy in which two alleles in an individual cell can be cut into equal fragments and tend to be amplified simultaneously. As a new single-cell long-read genome sequencing method, Refresh-seq features much lower allele dropout rate compared with SMOOTH-seq. Furthermore, we apply Refresh-seq to 688 sperm cells and 272 female haploid cells (secondary polar bodies and parthenogenetic oocytes) from F1 hybrid mice. We acquire high-resolution genetic map of mouse meiosis recombination at low sequencing depth and reveal the sexual dimorphism in meiotic crossovers. We also phase the structure variations (deletions and insertions) in sperm cells and female haploid cells with high precision. Refresh-seq shows great performance in screening aneuploid sperm cells and oocytes due to the low allele dropout rate and has great potential for medical applications such as preimplantation genetic diagnosis.

96 The effect of embryo stage and biopsy on embryo viability

Abstract The importance of embryo biopsy is running a 50K genomic test will be completed on the DNA biopsy, giving us the ability to collect genetic prediction data before the calf is even born. The objective of this study was to compare the viability of bovine embryos (n = 24) at different stages of embryo maturation, after microblade biopsy and embryo transfer. This process was achieved by taking a small biopsy of each embryo. The results of aspirating oocytes from packing house ovaries and in vitro fertilization (IVF), within a 48 h time period marked d 0. After a 7-d incubation period, the results consisted of 14 blastocysts and 10 early blastocysts. The final sample size, of 24 embryos, differing in stages between early blastocyst (TRT 6) and blastocyst (TRT 7). All the embryos, except for one, was a Grade 1 embryo. On d 7 the embryos were grouped by stage of embryo. Each embryo was washed, and biopsied with a microblade by a single technician. After the biopsy, the embryos were incubated for a 24 h period. Immediately after the incubation period, each embryo was analyzed for viability. On d 8, TRT 7 embryos had a 50% viability rate (n = 7), whereas TRT 6 embryos had a 70% viability rate (n = 7). Data were analyzed using GLIMMIX procedure of SAS 9.4. The viability did not differ between either treatment (P = 0.58). However, the biopsy of each embryo resulted in a significant effect on embryo viability (P < 0.01). In conclusion, using embryo biopsy and the stage of the embryo may affect embryo viability.

Lessons learned from over 64,000 embryos (day 3 embryos or blastocysts) subjected to PGT-A in the same laboratory: general results, recurrence pattern and analysis of the indications

Research questionWhat is the influence of biological, technical and clinical factors on PGT-A embryo outcomes and what is the recurrence pattern? DesignRetrospective study including 64,701 embryos undergoing PGT-A in the same laboratory between 2011 and 2019. Biopsies were performed at the day 3 embryo stage (48.3%) or blastocyst stage (51.7%). Advanced maternal age (AMA) was the main indication (65.6%). ResultsThe aneuploidy rate (AR) was 67.8%, higher in women >35 years than in ≤35 years (71.8% vs 47.4%), and higher in day 3 embryo vs blastocyst biopsies (77.50% vs 58.60%). The trisomy/ monosomy ratio was 1.0 on blastocysts vs 0.8 in day 3 embryos. Trisomy 21 was present in 4.9% of the embryos. In aneuploid embryos, the probability of having ≥1-involved chromosome followed a decreasing exponential pattern. The probability of an embryo being was constant around 30% (40% in blastocysts, 20% in day 3 embryos). The cumulative probability of having ≥1 euploid embryo after 10 biopsied embryos was 95% in blastocysts and 80% in day-3 embryos. AMA was associated with a much higher AR than all other indications, which among them had similar AR and chromosomal involvement. ConclusionsThere is a considerable decrease in AR from blastocysts to day 3 embryos, which is most notable for monosomies. While AMA shows an increase in AR and a specific chromosomal pattern of involvement, the remaining indications showed a similar AR and chromosomal pattern. Even after producing many consecutive aneuploid embryos, the possibility of obtaining a euploid embryo is not negligible.

Predictive factors of aneuploidy in infertile patients undergoing IVF: a retrospective analysis in a private IVF practice

BackgroundPGT-A has become an important part of IVF treatments. Despite its increased use, there are contradicting results on its role in improving reproductive outcomes of ART cycles. Given that aneuploidy is a main limiting factor for IVF success, we aimed to study the predictive factors of aneuploidy in infertile patients undergoing IVF and hence highlight the patients who would benefit the most from genetic testing.ResultsA retrospective analysis of 1242 blastocysts biopsied in the setting of PGT-A cycles was performed. The euploid group included 703 embryos, while the aneuploid group had 539 embryos. The factors included in the analyses were the couple’s history as well as the embryo characteristics. The primary outcome was the rate of aneuploid embryos per patient’s history as well as per embryo characteristics. The aneuploidy rate (AR) in our cohort was 43.4%. The woman’s age was found to be a significant predictor (OR 1.045, 95% CI 1.008–1.084, p = 0.016). Biopsy on day 5 as well as degree of expansion 3 was also found to affect significantly (OR 0.724, 95% CI .541–.970, p = 0.03 and OR 2.645, 95% CI 1.252–5.585, p = 0.011). Lack of consanguinity decreased the AR by an OR 0.274 with 95% CI .137–.547, p < 0.001. The number of blastocysts available, trophectoderm quality, embryo grade, gonadotropins as well as trigger used were not found to be significant predictors (p = 0.495, 0.649, 0.264, 0.717 and 0.659 respectively).ConclusionAdvanced female age, consanguinity, the day of embryo biopsy, and the degree of blastocyst expansion were all found to affect the incidence of AR. The age of the male partner, cause of infertility, and grade of embryo at biopsy were not found to correlate with aneuploidy.

Preimplantation genetic testing in the current era, a review.

Preimplantation genetic testing (PGT), also referred to as preimplantation genetic diagnosis (PGD), is an advanced reproductive technology used during in vitro fertilization (IVF) cycles to identify genetic abnormalities in embryos prior to their implantation. PGT is used to screen embryos for chromosomal abnormalities, monogenic disorders, and structural rearrangements. Over the past few decades, PGT has undergone tremendous development, resulting in three primary forms: PGT-A, PGT-M, and PGT-SR. PGT-A is utilized for screening embryos for aneuploidies, PGT-M is used to detect disorders caused by a single gene, and PGT-SR is used to detect chromosomal abnormalities caused by structural rearrangements in the genome. In this review, we thoroughly summarized and reviewed PGT and discussed its pros and cons down to the minutest aspects. Additionally, recent studies that highlight the advancements of PGT in the current era, including their future perspectives, were reviewed. This comprehensive review aims to provide new insights into the understanding of techniques used in PGT, thereby contributing to the field of reproductive genetics.

A critical view on using "life not worth living" in the bioethics of assisted reproduction.

This paper critically engages with how life not worth living (LNWL) and cognate concepts are used in the field of beginning-of-life bioethics as the basis of arguments for morally requiring the application of preimplantation genetic diagnosis (PGD) and/or germline genome editing (GGE). It is argued that an objective conceptualization of LNWL is largely too unreliable in beginning-of-life cases for deriving decisive normative reasons that would constitute a moral duty on the part of intending parents. Subjective frameworks are found to be more suitable to determine LNWL, but they are not accessible in beginning-of-life cases because there is no subject yet. Conceptual and sociopolitical problems are additionally pointed out regarding the common usage of clear case exemplars. The paper concludes that a moral requirement for the usage of PGD and GGE cannot be derived from the conceptual base of LNWL, as strong reasons that can be reliably determined are required to limit reproductive freedom on moral grounds. Educated predictions on prospective well-being might still be useful regarding the determination of moral permissibility of PGD and/or GGE. It is suggested that due to the high significance of subjective experience in the normativity of beginning-of-life bioethics, the discipline is called to more actively realize the inclusion of people with disabilities. This regards for instance research design, citation practices, and language choices to increase the accessibility of societal debates on the reproductive ethics of genetic technologies.

The reproductive potential of vitrified-warmed euploid embryos declines following repeated uterine transfers

BackgroundRecurrent implantation failure (RIF) represents a vague clinical condition with an unclear diagnostic challenge that lacks solid scientific underpinning. Although euploid embryos have demonstrated consistent implantation capabilities across various age groups, a unanimous agreement regarding the advantages of preimplantation genetic testing for aneuploidy (PGT-A) in managing RIF is absent. The ongoing discussion about whether chromosomal aneuploidy in embryos significantly contributes to recurrent implantation failure remains unsettled. Despite active discussions in recent times, a universally accepted characterization of recurrent implantation failure remains elusive. We aimed in this study to measure the reproductive performance of vitrified-warmed euploid embryos transferred to the uterus in successive cycles.MethodsThis observational cohort study included women (n = 387) with an anatomically normal uterus who underwent oocyte retrieval for PGT-A treatment with at least one biopsied blastocyst, between January 2017 and December 2021 at a university-affiliated public fertility center. The procedures involved in this study included ICSI, blastocyst culture, trophectoderm biopsy and comprehensive 24-chromosome analysis of preimplantation embryos using Next Generation Sequencing (NGS). Women, who failed a vitrified-warmed euploid embryo transfer, had successive blastocyst transfer cycles (FET) for a total of three using remaining cryopreserved euploid blastocysts from the same oocyte retrieval cycle. The primary endpoints were sustained implantation rate (SIR) and live birth rate (LBR) per vitrified-warmed single euploid embryo. The secondary endpoints were mean euploidy rate (m-ER) per cohort of biopsied blastocysts from each patient, as well as pregnancy and miscarriage rates.ResultsThe mean age of the patient population was 33.4 years (95% CI 32.8–33.9). A total of 1,641 embryos derived from the first oocyte retrieval cycle were biopsied and screened. We found no associations between the m-ER and the number of previous failed IVF cycles among different ranges of maternal age at oocyte retrieval (P = 0.45). Pairwise comparisons showed a significant decrease in the sustained implantation rate (44.7% vs. 30%; P = 0.01) and the livebirth rate per single euploid blastocyst (37.1% vs. 25%; P = 0.02) between the 1st and 3rd FET. The cumulative SIR and LBR after up to three successive single embryo transfers were 77.1% and 68.8%, respectively. We found that the live birth rate of the first vitrified-warmed euploid blastocyst transferred decreased significantly with the increasing number of previously failed IVF attempts by categories (45.3% vs. 35.8% vs. 27.6%; P = 0.04). A comparable decrease in sustained implantation rate was also observed but did not reach statistical significance (50% vs. 44.2 vs. 37.9%; P = NS). Using a logistic regression model, we confirmed the presence of a negative association between the number of previous IVF failed attempts and the live birth rate per embryo transfer cycle (OR = 0.76; 95% CI 0.62–0.94; P = 0.01).ConclusionsThese findings are vital for enhancing patient counseling and refining management strategies for individuals facing recurrent implantation failure. By tailoring interventions based on age and ovarian reserve, healthcare professionals can offer more personalized guidance, potentially improving the overall success rates and patient experiences in fertility treatments.Trial registration numberN/A.

PGT and deferred embryo transfer: is blastocyst biopsy more effective than cleaved embryo biopsy?

Blastocyst biopsy has recently been implemented in our laboratory for PGT with a "freeze all" indication. The aim of this study is to compare PGT results between embryos biopsied at the cleaved and embryos biopsied at the blastocyst stage. This is a retrospective cohort study conducted from January 2017 to December 2022 in France. All couples with a "freeze all" indication the day of hCG trigerring during the study period were included in the study. Patients were retrospectively assigned in one group of two groups based on the day of embryo biopsy: the cleavage group if a blastomere biopsy was performed on day 3/4 or the blastocyst group if a trophectoderm biopsy was performed on day 5/6. We evaluated and compared the results between the two groups for biological parameters and clinical outcomes. In total, 325 PGT cycles (291 patients) were included in our study. Frozen-thawed embryo transfer was performed for 285 cycles, 122 in the blastocyst group and 163 in the cleavage group. The number of biopsied embryos per cycle is significantly higher in the cleavage group with a mean of 7.2±4.1 embryos biopsied per cycle vs. 2.9±2.8 embryos in the blastocyst group (p<0.001). The rate of the useful embryos was similar between the two groups with 14.6% of frozen healthy embryos among the 1352 cleaved embryos obtained in blastocyst group, compared to 17.1% in the cleavage group. No significant differences in clinical pregnancy rate per transfer and implantation rate were observed between the blastocyst and cleavage groups (36.4% vs. 40.4% and 33.1% vs. 33.2% respectively). For "freeze all" PGT cycles, the day of embryo biopsy (cleaved vs blastocyst biopsy) does not impact pregnancy outcomes. Knowing how to perform embryo biopsy at different stages helps to better organize daily laboratory activity and to rescue some undiagnosed embryos after day 3 biopsy.

PREIMPLANTATION GENETIC DIAGNOSIS FOR HUNTINGTON’S DISEASE - CASE REPORT AND LITERATURE REVIEW

Background: Huntington’s disease is a rare, neurodegenerative, autosomal dominant disorder with adult onset caused by an expansion of 36 or more CAG trinucleotide repeats in the HTT gene.  In Brazil and in some other countries, carriers of HTT’s expanded allele of submitted to in vitro fertilization procedure can investigate embryos genetically to identify the ones that have inherited the expanded allele and the ones that inherited only the normal size alleles. In some instances, an individual has a positive familial history for the disease and do not want to know his/her personal carrier status but is willing to conceive children without the disease. Objective: to demonstrate the reproductive possibilities available to patients with Huntington disease through a case report and literature review. Methods: Here, we discussed the application and viability of the genetic screening techniques, based on a non-disclosure case of Preimplantation Genetic Testing (PGT). Results: a couple submitted to a non-disclosure test for Huntington disease was submitted to IVF, embryo biopsy and genetic analysis of the samples due to a familial history of the condition. Chromosome and mutation specific tests were applied, and one embryo was selected for uterine transfer. The couple was not informed why the other embryos were discharged. Conclusion: Although many ethical and practical aspects are involved in this decision, a non-disclosure PGT can be offered as an option for these couples, besides sperm, egg or embryo adoption, or child adoption.

Does embryo biopsy, independent of vitrification, impact perinatal outcomes? An analysis of perinatal outcomes following preimplantation genetic testing biopsy in fresh and frozen embryo transfer cycles

Does embryo biopsy, independent of vitrification, impact perinatal outcomes? An analysis of perinatal outcomes following preimplantation genetic testing biopsy in fresh and frozen embryo transfer cycles