Haplotyping-based preimplantation genetic testing reveals parent-of-origin specific mechanisms of aneuploidy formation.
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ABSTRACT:
SUBMITTER: Tsuiko O
PROVIDER: S-EPMC8497526 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Uterus transplantation is an emerging treatment for uterine factor infertility. In vitro fertilization with cryopreservation of embryos prior is required before a patient can be listed for transplant. Whether or not to perform universal preimplantation genetic testing for aneuploidy should be addressed by centers considering a uterus transplant program. The advantages and disadvantages of preimplantation genetic testing for aneuploidy in this unique population are presented. The available literature is reviewed to determine the utility of preimplantation genetic testing for aneuploidy in uterus transplantation protocols. Theoretical benefits of preimplantation genetic testing for aneuploidy include decreased time to pregnancy in a population that benefits from minimization of exposure to immunosuppressive agents and decreased chance of spontaneous abortion requiring a dilation and curettage. Drawbacks include increased cost per in vitro fertilization cycle, increased number of required in vitro fertilization cycles to achieve a suitable number of embryos prior to listing for transplant, and a questionable benefit to live birth rate in younger patients. Thoughtful consideration of whether or not to use preimplantation genetic testing for aneuploidy is necessary in uterus transplant trials. Age is likely a primary factor that can be useful in determining which uterus transplant recipients benefit from preimplantation genetic testing for aneuploidy.
| S-EPMC8064656 | biostudies-literature
Project description:Whole-chromosome imbalances affect over half of early human embryos and are the leading cause of pregnancy loss. While these errors frequently arise in oocyte meiosis, many such whole-chromosome abnormalities affecting cleavage-stage embryos are the result of chromosome missegregation occurring during the initial mitotic cell divisions. The first wave of zygotic genome activation at the 4-8 cell stage results in the arrest of a large proportion of embryos, the vast majority of which contain whole-chromosome abnormalities. Thus, the full spectrum of meiotic and mitotic errors can only be detected by sampling after the initial cell divisions, but prior to this selective filter. Here, we apply 24-chromosome preimplantation genetic screening (PGS) to 28,052 single-cell day-3 blastomere biopsies and 18,387 multi-cell day-5 trophectoderm biopsies from 6,366 in vitro fertilization (IVF) cycles. We precisely characterize the rates and patterns of whole-chromosome abnormalities at each developmental stage and distinguish errors of meiotic and mitotic origin without embryo disaggregation, based on informative chromosomal signatures. We show that mitotic errors frequently involve multiple chromosome losses that are not biased toward maternal or paternal homologs. This outcome is characteristic of spindle abnormalities and chaotic cell division detected in previous studies. In contrast to meiotic errors, our data also show that mitotic errors are not significantly associated with maternal age. PGS patients referred due to previous IVF failure had elevated rates of mitotic error, while patients referred due to recurrent pregnancy loss had elevated rates of meiotic error, controlling for maternal age. These results support the conclusion that mitotic error is the predominant mechanism contributing to pregnancy losses occurring prior to blastocyst formation. This high-resolution view of the full spectrum of whole-chromosome abnormalities affecting early embryos provides insight into the cytogenetic mechanisms underlying their formation and the consequences for human fertility.
| S-EPMC4619652 | biostudies-literature
Project description:Objective The purpose of this study was to evaluate the influence of abnormal semen parameters on embryo aneuploidy based on single nucleotide polymorphism microarray (SNP array). Methods A total of 464 blastocysts from 103 PGT-A cycles were analyzed. The embryo quality and embryo aneuploidy rates were compared between different groups which divided by male semen parameters (sperm concentration, motility, morphology, and DFI) according the WHO criteria (2021). Results The total blastocysts chromosome aneuploidy rate was 42.3% (191/452). In the teratozoospermia group, the good-quality embryo and blastocyst formation rate were lower than the normal group(44.4% vs 60.7%, P <0.01; 33.3% vs 43.5%, P <0.05), The good-quality embryo rate in normal DFI group was significantly higher than high-DFI group (59.0% vs 48.4%, P < 0.05). The blastocyst aneuploidy rate in low sperm concentration group, and high DFI group was no differences between with that in normal sperm concentration and DFI group (47.7% vs 37.8% and 44.7% vs 37.8%, P>0.05). The aneuploid rate of blastocyst in teratozoospermic and asthenozoospermia group was significantly higher than that of normal morphology and motility group (50.0% vs 34.0% and 46.7% vs 33.7%, P<0.05). Conclusion Our study revealed that sperm DFI were positively correlated with blastocyst aneuploidy rate, while sperm motility and sperm morphology rate were negatively correlated with blastocyst aneuploidy rate. Abnormal semen parameters may affect embryo quality and increase the aneuploidy rate of blastocyst chromosomes, suggesting that in clinical practice of assisted reproduction patients with abnormal semen parameters can be treated in advance to improve sperm quality, so as to reduce the impact on embryo quality and achieve a better pregnancy outcome.
| S-EPMC9908608 | biostudies-literature
Project description:There is a high incidence of chromosomal abnormalities in early human embryos, whether they are generated by natural conception or by assisted reproductive technologies (ART). Cells with chromosomal copy number deviations or chromosome structural rearrangements can compromise the viability of embryos; much of the naturally low human fecundity as well as low success rates of ART can be ascribed to these cytogenetic defects. Chromosomal anomalies are also responsible for a large proportion of miscarriages and congenital disorders. There is therefore tremendous value in methods that identify embryos containing chromosomal abnormalities before intrauterine transfer to a patient being treated for infertility-the goal being the exclusion of affected embryos in order to improve clinical outcomes. This is the rationale behind preimplantation genetic testing for aneuploidy (PGT-A) and structural rearrangements (-SR). Contemporary methods are capable of much more than detecting whole chromosome abnormalities (e.g., monosomy/trisomy). Technical enhancements and increased resolution and sensitivity permit the identification of chromosomal mosaicism (embryos containing a mix of normal and abnormal cells), as well as the detection of sub-chromosomal abnormalities such as segmental deletions and duplications. Earlier approaches to screening for chromosomal abnormalities yielded a binary result of normal versus abnormal, but the new refinements in the system call for new categories, each with specific clinical outcomes and nuances for clinical management. This review intends to give an overview of PGT-A and -SR, emphasizing recent advances and areas of active development.
| S-EPMC7349251 | biostudies-literature
Project description:Preimplantation genetic testing for aneuploidy (PGT-A) reduces miscarriage risk, increases the success of IVF, shortens time to pregnancy, and reduces multiple gestation rates without compromising outcomes. The progression of PGT-A has included common application of next-generation sequencing (NGS) from single nucleotide polymorphism microarray, quantitative real-time PCR, and array comparative hybridization platforms of analysis. Additional putative advances in PGT-A capability include classifying embryos as mosaic and predicting the presence of segmental imbalance. A critical component in the process of technical validation of these advancements involves evaluation of concordance between reanalysis results and initial testing results. While many independent studies have investigated the concordance of results obtained from the remaining embryo with the original PGT-A diagnosis, compilation and systematic analysis of published data has not been performed. Here, we review results from 26 primary research articles describing concordance in 1271 human blastocysts from 2260 pairwise comparisons. Results illustrate significantly higher discordance from PGT-A methods which utilize NGS and include prediction of mosaicism or segmental imbalance. These results suggest caution when considering new iterations PGT-A.
| S-EPMC8259107 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2019-10-08 | GSE133856 | GEO
Project description:PurposeTo assess whether preimplantation genetic testing for aneuploidies (PGT-A) at the blastocyst stage improves clinical outcomes compared with transfer of embryos without PGT-A in poor ovarian response (POR) patients.MethodsRetrospective cohort study of IVF cycles from 2016 to 2019 at a single academic fertility center. IVF cycles with POR and four or fewer oocytes retrieved were stratified into PGT-A (n = 241) and non-PGT (n = 112) groups. In PGT-A cycles, trophectoderm biopsy, next-generation sequencing with 24-chromosome screening, and single euploid frozen embryo transfer were performed. In non-PGT cycles, fresh or frozen transfer of untested embryos on day 3 or 5 was performed. Main outcomes included live birth rate and miscarriage rate per retrieval.Result(s)Patients who underwent PGT-A cycles were significantly less likely to reach embryo transfer compared with those who underwent non-PGT cycles (13.7% vs 70.6%). The live birth rate per retrieval did not differ between the PGT-A and non-PGT groups (6.6% vs 5.4%). Overall, the miscarriage rate was low. The PGT-A group demonstrated a significantly lower miscarriage rate per retrieval (0.4% vs 3.6%) as well as per pregnancy (5.9% vs 40.0%) compared with the non-PGT group. The number needed to treat to avoid one clinical miscarriage was 31 PGT-A cycles.Conclusion(s)PGT-A did not improve live birth rate per retrieval in POR patients with four or fewer oocytes retrieved. PGT-A was associated with a lower miscarriage rate; however, a fairly large number of PGT-A cycles were needed to prevent one miscarriage.
| S-EPMC7244670 | biostudies-literature
Project description:PurposeThis study evaluated the potential viability of embryos with low mosaicism level (< 50%) by comparing the clinical outcomes of single mosaic versus euploid blastocyst transfer. In addition, the live birth outcomes for various types of mosaicism with respect to abnormalities in chromosome structure and content were analyzed.MethodsThis study included patients who underwent in vitro fertilization with preimplantation genetic testing for aneuploidy (PGT-A). The PGT-A cycles performed through next-generation sequencing with single euploid or mosaic embryo transfers were included. We collected 299 frozen single embryo transfer cycles-216 single euploid and 83 mosaic-between July 2016 and July 2018. This study analyzed clinical outcomes, including fetal karyotyping by using amniocentesis, gestational age at delivery, and live birth weight after single mosaic embryo transfer.ResultsThe average birth weight of infants in the euploid and mosaic blastocyst transfer groups was 3146.2 and 2997.7 g, respectively. The karyotyping results of prenatal diagnosis in all pregnant women were normal. Our study indicated that mosaic embryos can develop into euploid healthy infants with various levels or types of mosaicism. No significant difference was observed between infants from euploid and mosaic blastocyst transfers.ConclusionIf patients have no euploid embryos, mosaic embryos can be transferred as they have potential for implantation and development into euploid healthy infants. This study is invaluable for counseling clinical results after single mosaic embryo transfers.
| S-EPMC7492347 | biostudies-literature
Project description:To investigate the contribution of parental genomes to early embryogenesis, we systematically profiled the single-cell transcriptomes of human biparental and uniparental embryos from one-cell to morula stages. We observed that uniparental embryos exhibit variable and overall less activation patterns of embryonic genome activation (EGA). Comparative transcriptome analysis identified 807 maternally biased expressed genes (MBGs) and 581 paternally biased expressed genes (PBGs) in preimplantation stages. MBGs became obviously appeared at the four-cell stage and contribute to EGA initiation, whereas PBGs preferentially appeared at the eight-cell stage, and possibly affect embryo compaction and trophectoderm specification. Regulatory network analysis revealed DUX4, EGR2 and DUXA as key transcription factors for MBGs expression as well as ZNF263 and KLF3 for PBGs expression. Furthermore, we revealed that the expression of MBGs and PBGs，especially PBGs, probably due to DNA methylation differences between the parental genomes. Together, our results provide a valuable resource to understand parental genome activation and may help to dissect parent-of-origin effect on early human development.
2019-10-08 | GSE133855 | GEO
Project description:Study questionDo donor oocyte recipients benefit from preimplantation genetic testing for aneuploidy (PGT-A)?Summary answerPGT-A did not improve the likelihood of live birth for recipients of vitrified donor oocytes, but it did avoid embryo transfer in cycles with no euploid embryos.What is known alreadyRelative to slow freeze, oocyte vitrification has led to increased live birth from cryopreserved oocytes and has led to widespread use of this technology in donor egg IVF programs. However, oocyte cryopreservation has the potential to disrupt the meiotic spindle leading to abnormal segregation of chromosome during meiosis II and ultimately increased aneuploidy in resultant embryos. Therefore, PGT-A might have benefits in vitrified donor egg cycles. In contrast, embryos derived from young donor oocytes are expected to be predominantly euploid, and trophectoderm biopsy may have a negative effect relative to transfer without biopsy.Study design, size, durationThis is a paired cohort study analyzing donor oocyte-recipient cycles with or without PGT-A performed from 2012 to 2018 at 47 US IVF centers.Participants/materials, setting, methodsVitrified donor oocyte cycles were analyzed for live birth as the main outcome measure. Outcomes from donors whose oocytes were used by at least two separate recipient couples, one couple using PGT-A (study group) and one using embryos without PGT-A (control group), were compared. Generalized estimating equation models controlled for confounders and nested for individual donors contributing to both PGT-A and non-PGT-A cohorts, enabling a single donor to serve as her own control.Main results and the role of chanceIn total, 1291 initiated recipient cycles from 223 donors were analyzed, including 262 cycles with and 1029 without PGT-A. The median aneuploidy rate per recipient was 25%. Forty-three percent of PGT-A cycles had only euploid embryos, whereas only 12.7% of cycles had no euploid embryos. On average 1.09 embryos were transferred in the PGT-A group compared to 1.38 in the group without PGT-A (P < 0.01). Live birth occurred in 53.8% of cycles with PGT-A versus 55.8% without PGT-A (P = 0.44). Similar findings persisted in cumulative live birth from per recipient cycle.Limitations, reasons for cautionPooled clinical data from 47 IVF clinics introduced PGT-A heterogeneity as genetic testing were performed using different embryology laboratories, PGT-A companies and testing platforms.Wider implications of the findingsPGT-A testing in donor oocyte-recipient cycles does not improve the chance for live birth nor decrease the risk for miscarriage in the first transfer cycle but does increase cost and time for the patient. Further studies are required to test if our findings can be applied to the young infertility patient population using autologous oocytes.Study funding/competing interest(s)No external funding was used for this study. There are no conflicts of interest to declare.Trial registration numberN/A.
| S-EPMC7821705 | biostudies-literature