Human embryos with unevenly sized blastomeres have lower pregnancy and implantation rates: indications for aneuploidy and multinucleation.

@article{Hardarson2001HumanEW,
  title={Human embryos with unevenly sized blastomeres have lower pregnancy and implantation rates: indications for aneuploidy and multinucleation.},
  author={T. Hardarson and C. Hanson and A. Sj{\"o}gren and K. Lundin},
  journal={Human reproduction},
  year={2001},
  volume={16 2},
  pages={
          313-8
        }
}
Uneven blastomere cleavage in human embryos of 'good morphology', i.e. those normally used for transfer, is a phenomenon which has been poorly investigated. [...] Key Method In the first part of the study, 378 embryo transfers performed over a 3-year period were analysed retrospectively, where all the transferred embryos in each cycle were of identical morphology score and cleavage stage.Expand
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An embryo cleavage pattern based on the relative blastomere size as a function of cell number for predicting implantation outcome.
TLDR
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Fragmentation removal had a positive effect on human fragmented embryos and produced the best quality blastocysts, and apoptotic index was also significantly reduced after embryo fragmentation removal. Expand
Planar embryos have poor prognosis in terms of blastocyst formation and implantation.
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Binucleated and micronucleated blastomeres in embryos derived from human assisted reproduction cycles.
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Embryos cultured in vitro with multinucleated blastomeres have poor implantation potential in human in-vitro fertilization and intracytoplasmic sperm injection.
TLDR
This study shows that embryos with one or more multinucleated blastomeres have a poorer implantation potential than embryos with mononucleated Blastomeres, and should hence only be considered when insufficient numbers of embryos with only monon nucleatedblastomeres are present. Expand
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The results substantiate the idea of the superiority of 4-cell embryos and demonstrate that minor amounts of fragments in the embryo may not be of any importance. Expand
Multinucleation in normally fertilized embryos is associated with an accelerated ovulation induction response and lower implantation and pregnancy rates in in vitro fertilization-embryo transfer cycles.
TLDR
The presence of multinucleated blastomeres in normally fertilized embryos is associated with a more effusive response to gonadotropin therapy and is indicative of a poor developmental outcome and lower clinical pregnancy rates. Expand
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A new method to evaluate embryo viability based on the timing of the first cell division is proposed, 'early cleavage' as a simple and effective non-invasive method for selection and evaluation of embryos prior to transfer. Expand
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The data show that oocyte quality and pronuclear embryo morphology are related to implantation and that pronuclear embryos can be successfully selected for embryo transfer. Expand
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The data show a slightly higher incidence of abnormal embryos compared to those obtained with FISH in non-cryopreserved embryos and confirm that the majority of preimplantation embryos fertilised in vitro contain abnormal blastomeres. Expand
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TLDR
A 4-point embryo score is devised in which embryos are assigned 1 point each if they are cleaved, present no fragmentation, display no irregularities, and have four cells to predict the likelihood of successful implantation after in-vitro fertilization (IVF). Expand
Embryo morphology, developmental rates, and maternal age are correlated with chromosome abnormalities.
TLDR
It is demonstrated that, in morphologically and developmentally normal human embryos, cleavage-stage aneuploidy significantly increases with maternal age, and the results suggest that implantation failure in older women largely could be due to aneuPLoidy. Expand
Chromosome abnormalities in embryos obtained after conventional in vitro fertilization and intracytoplasmic sperm injection.
TLDR
If the parents are chromosomally normal, the results indicate that, at the embryo level and before any embryo selection has occurred in utero, ICSI does not produce more numerical chromosomal abnormalities than conventional IVF. Expand
Relationship between morphology and chromosomal constitution in human preimplantation embryo
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These results, pooled with data drawn from previous reports, demonstrated the prognostic value of the embryo grading system as a means for eliminating chromosomally abnormal embryos and suggested that some aspects of the IVF process might be responsible for the occurrence of these abnormalities. Expand
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