Preimplantation genetic diagnosis of chromosome abnormalities: implications from the outcome for couples with chromosomal rearrangements

2003 ◽  
Vol 23 (8) ◽  
pp. 652-662 ◽  
Author(s):  
M. Simopoulou ◽  
J. C. Harper ◽  
E. Fragouli ◽  
A. Mantzouratou ◽  
B. E. Speyer ◽  
...  
Keyword(s):  
Preimplantation Genetic Diagnosis ◽  
Chromosomal Rearrangements ◽  
Genetic Diagnosis ◽  
Chromosome Abnormalities

Morphometric analysis and developmental comparison of embryos from carriers with balanced chromosomal rearrangements in preimplantation genetic diagnosis cycles

2016 ◽  
Vol 28 (12) ◽  
pp. 1953
Author(s):  
Baoheng Gui ◽  
Zhongyuan Yao ◽  
Yanru Huang ◽  
Libin Mei ◽  
Yanping Li ◽  
...  
Keyword(s):  
Preimplantation Genetic Diagnosis ◽  
Chromosomal Rearrangements ◽  
In Situ Hybridisation ◽  
Genetic Diagnosis ◽  
Developmental Outcomes ◽  
Blastocyst Stage ◽  
Qualitative Assessment ◽  
Fluorescence In Situ Hybridisation ◽  
Morphometric Characteristics ◽  
Developmental Potential

The morphological parameters of embryos from 22 carriers with balanced chromosomal rearrangements (CRs) were quantified and evaluated to determine their possible link to chromosomal composition. The morphometric characteristics of 168 embryos diagnosed by fluorescence in situ hybridisation were measured using an imaging tool and then analysed retrospectively. The mean zygotic diameter of normal–balanced embryos was significantly smaller compared with that of abnormal embryos (P = 0.015). In addition, the reduction in total cytoplasmic volume for Day-3 embryos was significantly lower in normal or balanced embryos than in abnormal embryos (P = 0.027). Moreover, the pronuclear volumes of embryos that failed to reach the blastocyst stage were significantly smaller compared with those of blastocysts (P = 0.016). These findings indicate that morphometric characteristics are correlated with developmental outcomes as well as with chromosomal composition in embryos from balanced CR carriers. However, an effective indicator of developmental outcomes may not accurately reflect chromosomal composition. Combining morphometric and traditional qualitative assessment may increase the precision and standardisation of embryo evaluation as well as contributing to improved efficiency of preimplantation genetic diagnosis by selecting embryos with high developmental potential and preferentially testing embryos predicted to have a low risk of chromosomal imbalance.

141 BIOPSY TECHNIQUE IN BOVINE EMBRYOS PRODUCED IN VITRO AT EARLY STAGES OF DEVELOPMENT: EVALUATION OF QUALITY AND DEVELOPMENT CAPACITY

2008 ◽  
Vol 20 (1) ◽  
pp. 151
Author(s):  
J. Polisseni ◽  
M. O. Guerra ◽  
R. V. Serapião ◽  
M. M. Pereira ◽  
I. M. Folhadella ◽  
...  
Keyword(s):  
Preimplantation Genetic Diagnosis ◽  
Embryo Quality ◽  
Genetic Diagnosis ◽  
Blastocyst Stage ◽  
Chromosome Abnormalities ◽  
Control Group ◽  
Bovine Embryos ◽  
Blastocyst Rate ◽  
Number Of Cells

One of the causes of embryo mortality is chromosome abnormalities that occur during gametogenesis, fertilization, and embryo early development. Thus, a combination of morphological standards and techniques of molecular analyses could identify abnormal embryos. Preimplantation genetic diagnosis (PGD) is an emergent technology for use with farm animal embryos. With this procedure, blastomeres are removed by the biopsy of embryos at the 8- to 16-cell stage to provide cells for analyses of chromosome abnormalities prior to transfer. The aim of this study was to evaluate the effect of biopsy in bovine 8- to 16-cell embryos fertilized in vitro on embryo quality and subsequent development in vitro. A group of 706 oocytes were obtained from slaughterhouse ovaries, matured, and fertilized in vitro at 38.8�C with 95% humidified air and 5% CO2. The zygotes were semi-denuded and cultured in CR2aa medium under the same conditions as for in vitro fertilization. The rate of cleavage was 78.20%. Three days after fertilization, part of the 8- to 16-cell (298/706) embryos were distributed randomly across two groups: control (n = 103) and biopsy (n = 92) of blastomeres, and then returned to in vitro embryo culture to evaluate development until the blastocyst stage and the capacity to hatch. The amount of cells removed was one-fourth of the embryo. The blastocyst rate was evaluated on Day 8 after fertilization and the hatching rate on Day 10. Embryo morphology and quality were evaluated as previously described in the International Embryo Transfer Society manual (1998). To evaluate overall quality, embryos were stained on the 10th day of culture and the blastomeres were counted with the imaging software AxioVision 3.1 (Carl Zeiss, Feldbach, Switzerland). The blastocyst rate was analyzed by treatment groups with the chi-square test and the number of cells/embryo was analyzed by ANOVA with SAS (SAS Institute, Inc., Cary, NC, USA). The percentage of 8- to 16-cell embryos that developed to the blastocyst stage was similar (P > 0.05) between the control (66.0%, 68/103) and the biopsied (53.3%, 49/92) groups. Furthermore, no difference was noted in the hatching rates between the control group and the biopsied group (42.6%, 29/42 v. 44.9%, 22/49, respectively). Overall, no impact was detected on embryo quality from embryo biopsy with no difference in mean (�SE) blastocyst cell number between the control group (blastocysts: 67.1 � 3.1; expanded blastocysts: 100.7 � 6.9; hatched blastocysts: 189.9 � 16.1) and the biopsied group (blastocysts: 61.1 � 5.5; expanded blastocysts: 121.87 � 10.6; hatched blastocysts: 187.3 � 18.5). In conclusion, the biopsy used on 8- to 16-cell bovine IVF-derived bovine embryos does not affect the subsequent embryo development and number of cells/embryo or blastocyst, showing that it can be used to provide genetic material for preimplantation genetic diagnosis without affecting embryo quality. This work was supported financially by FAPEMIG.

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