The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy Status
Previous studies have suggested that aneuploidy rates are co-related with cell asymmetry at the cleavage stage. A retrospective study was carried out to determine the significance of blastomere symmetry at the 4-cell stage on blastocyst grade and ploidy status. 732 Day 5/6 blastocysts from 191 patie...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
World Scientific Publishing
2019-06-01
|
| Series: | Fertility & Reproduction |
| Subjects: | |
| Online Access: | http://www.worldscientific.com/doi/epdf/10.1142/S2661318219500117 |
| _version_ | 1818413371883520000 |
|---|---|
| author | Diana Chieh Xing Tain Michelle Sheng Rong Lim Bee Lian Ng Elizabeth Hammond Pak Seng Wong |
| author_facet | Diana Chieh Xing Tain Michelle Sheng Rong Lim Bee Lian Ng Elizabeth Hammond Pak Seng Wong |
| author_sort | Diana Chieh Xing Tain |
| collection | DOAJ |
| description | Previous studies have suggested that aneuploidy rates are co-related with cell asymmetry at the cleavage stage. A retrospective study was carried out to determine the significance of blastomere symmetry at the 4-cell stage on blastocyst grade and ploidy status.
732 Day 5/6 blastocysts from 191 patients undergoing Pre-implantation Genetic Testing for Aneuploidy were analysed with time-lapse imaging (Embryoscope, Vitrolife) during 2017. Blastomere symmetry was measured at the first image of 4-cells on Day 2 by tabulating the mean diameter of 2 lines drawn perpendicularly on each blastomere.
Symmetry was defined as the blastomere diameter difference of ≤ 25%. Trophectoderm (TE) biopsy was performed on Day 5/6 followed by chromosomal evaluation using Next Generation Sequencing (VeriSeq Protocol, Illumina). Blastocyst grade was classified as either “Good” (inner cell mass (ICM) and TE, AA respectively), “Fair/Good” (AB, BA), “Fair” (BB) and “Poor” (early blastocyst grade 2 or TE grading of C). The significance of blastomere symmetry on blastocyst grade and ploidy status was measured using chi-square tests.
There was no significance difference in resulting blastocyst quality for symmetrical and asymmetrical embryos (Table 1: p = 0.10). Furthermore, there was no significance difference in the euploid rate (42.5% vs. 45.3%) or mosaic rate (22.1% vs. 16.2%) between symmetrical and asymmetrical embryos (p = 0.24).
In conclusion, the presence of asymmetrical blastomeres at the 4-cell stage do not impact the good quality blastocyst formation rate and euploidy rate for embryos that progress into blastocysts. However, this study excludes embryos that do not develop to the blastocyst stage and those with erratic division patterns, direct cleavage and reverse cleavage on Day 2, both of which have potential to influence ploidy result.
Asymmetrical 4-cell embryos have the potential for high quality euploid blastocyst progression and can be considered for day 2 embryo transfer in the absence of symmetrical 4-cell embryos. |
| first_indexed | 2024-12-14T11:02:09Z |
| format | Article |
| id | doaj.art-e03d22b5cbb4427c8c311d7753e988da |
| institution | Directory Open Access Journal |
| issn | 2661-3182 2661-3174 |
| language | English |
| last_indexed | 2024-12-14T11:02:09Z |
| publishDate | 2019-06-01 |
| publisher | World Scientific Publishing |
| record_format | Article |
| series | Fertility & Reproduction |
| spelling | doaj.art-e03d22b5cbb4427c8c311d7753e988da2022-12-21T23:04:43ZengWorld Scientific PublishingFertility & Reproduction2661-31822661-31742019-06-011211511810.1142/S266131821950011710.1142/S2661318219500117The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy StatusDiana Chieh Xing Tain0Michelle Sheng Rong Lim1Bee Lian Ng2Elizabeth Hammond3Pak Seng Wong4Sunfert International Fertility Centre, Unit 2-2, Level 2, Nexus, Bangsar South, 7, Jalan Kerinchi, 59200 Kuala Lumpur, MalaysiaSunfert International Fertility Centre, Unit 2-2, Level 2, Nexus, Bangsar South, 7, Jalan Kerinchi, 59200 Kuala Lumpur, MalaysiaSunfert International Fertility Centre, Unit 2-2, Level 2, Nexus, Bangsar South, 7, Jalan Kerinchi, 59200 Kuala Lumpur, MalaysiaFertility Associates, Level 3, Ascot Central, 7 Ellerslie Racecourse Drive, Private Bag 28910, Remuera, Auckland 1051, New ZealandSunfert International Fertility Centre, Unit 2-2, Level 2, Nexus, Bangsar South, 7, Jalan Kerinchi, 59200 Kuala Lumpur, MalaysiaPrevious studies have suggested that aneuploidy rates are co-related with cell asymmetry at the cleavage stage. A retrospective study was carried out to determine the significance of blastomere symmetry at the 4-cell stage on blastocyst grade and ploidy status. 732 Day 5/6 blastocysts from 191 patients undergoing Pre-implantation Genetic Testing for Aneuploidy were analysed with time-lapse imaging (Embryoscope, Vitrolife) during 2017. Blastomere symmetry was measured at the first image of 4-cells on Day 2 by tabulating the mean diameter of 2 lines drawn perpendicularly on each blastomere. Symmetry was defined as the blastomere diameter difference of ≤ 25%. Trophectoderm (TE) biopsy was performed on Day 5/6 followed by chromosomal evaluation using Next Generation Sequencing (VeriSeq Protocol, Illumina). Blastocyst grade was classified as either “Good” (inner cell mass (ICM) and TE, AA respectively), “Fair/Good” (AB, BA), “Fair” (BB) and “Poor” (early blastocyst grade 2 or TE grading of C). The significance of blastomere symmetry on blastocyst grade and ploidy status was measured using chi-square tests. There was no significance difference in resulting blastocyst quality for symmetrical and asymmetrical embryos (Table 1: p = 0.10). Furthermore, there was no significance difference in the euploid rate (42.5% vs. 45.3%) or mosaic rate (22.1% vs. 16.2%) between symmetrical and asymmetrical embryos (p = 0.24). In conclusion, the presence of asymmetrical blastomeres at the 4-cell stage do not impact the good quality blastocyst formation rate and euploidy rate for embryos that progress into blastocysts. However, this study excludes embryos that do not develop to the blastocyst stage and those with erratic division patterns, direct cleavage and reverse cleavage on Day 2, both of which have potential to influence ploidy result. Asymmetrical 4-cell embryos have the potential for high quality euploid blastocyst progression and can be considered for day 2 embryo transfer in the absence of symmetrical 4-cell embryos.http://www.worldscientific.com/doi/epdf/10.1142/S2661318219500117day 24-cell embryosymmetryasymmetryevenuneven |
| spellingShingle | Diana Chieh Xing Tain Michelle Sheng Rong Lim Bee Lian Ng Elizabeth Hammond Pak Seng Wong The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy Status Fertility & Reproduction day 2 4-cell embryo symmetry asymmetry even uneven |
| title | The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy Status |
| title_full | The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy Status |
| title_fullStr | The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy Status |
| title_full_unstemmed | The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy Status |
| title_short | The Influence of Day 2 Blastomere Symmetry on Blastocyst Grade and Ploidy Status |
| title_sort | influence of day 2 blastomere symmetry on blastocyst grade and ploidy status |
| topic | day 2 4-cell embryo symmetry asymmetry even uneven |
| url | http://www.worldscientific.com/doi/epdf/10.1142/S2661318219500117 |
| work_keys_str_mv | AT dianachiehxingtain theinfluenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT michelleshengronglim theinfluenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT beelianng theinfluenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT elizabethhammond theinfluenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT paksengwong theinfluenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT dianachiehxingtain influenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT michelleshengronglim influenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT beelianng influenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT elizabethhammond influenceofday2blastomeresymmetryonblastocystgradeandploidystatus AT paksengwong influenceofday2blastomeresymmetryonblastocystgradeandploidystatus |