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Park JK, Jeon Y, Bang S, Kim JW, Kwak IP, Lee WS. Time-lapse imaging of morula compaction for selecting high-quality blastocysts: a retrospective cohort study. Arch Gynecol Obstet 2024; 309:2897-2906. [PMID: 38649499 DOI: 10.1007/s00404-024-07461-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 03/04/2024] [Indexed: 04/25/2024]
Abstract
PURPOSE Before blastocyst development, embryos undergo morphological and metabolic changes crucial for their subsequent growth. This study aimed to investigate the relationship between morula compaction and blastocyst formation and the subsequent chromosomal status of the embryos. METHODS This retrospective cohort study evaluated embryo development (n = 371) using time-lapse imaging; 94 blastocysts underwent preimplantation genetic testing for aneuploidy (PGT-A). RESULTS The embryos were classified as fully (Group 1, n = 194) or partially (Group 2, n = 177) compacted. Group 1 had significantly higher proportions of good- and average-quality blastocysts than Group 2 (21.6% vs. 3.4%, p = 0.001; 47.9% vs. 26.6%, p = 0.001, respectively). The time from the morula stage to the beginning and completion of compaction and blastocyst formation was significantly shorter in Group 1 than in Group 2 (78.6 vs. 82.4 h, p = 0.001; 87.0 vs. 92.2 h, p = 0.001; 100.2 vs. 103.7 h, p = 0.017, respectively). Group 1 embryos had larger surface areas than Group 2 embryos at various time points following blastocyst formation. Group 1 blastocysts had significantly higher average expansion rates than Group 2 blastocysts (653.6 vs. 499.2 μm2/h, p = 0.001). PGT-A revealed a higher proportion of euploid embryos in Group 1 than in Group 2 (47.2% vs. 36.6%, p = 0.303). CONCLUSION Time-lapse microscopy uncovered a positive relationship between compaction and blastocyst quality and its association with embryo ploidy. Hence, compaction evaluation should be prioritized before blastocyst selection for transfer or cryopreservation.
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Affiliation(s)
- Jae Kyun Park
- Department of Obstetrics and Gynecology, Fertility Center of CHA Gangnam Medical Center, CHA University School of Medicine, 566 Nonhyeon-ro, Gangnam-gu, Seoul, 06135, Korea
| | - Yunmi Jeon
- Department of Obstetrics and Gynecology, Fertility Center of CHA Gangnam Medical Center, CHA University School of Medicine, 566 Nonhyeon-ro, Gangnam-gu, Seoul, 06135, Korea
| | - Soyoung Bang
- Department of Obstetrics and Gynecology, Fertility Center of CHA Gangnam Medical Center, CHA University School of Medicine, 566 Nonhyeon-ro, Gangnam-gu, Seoul, 06135, Korea
| | - Ji Won Kim
- Department of Obstetrics and Gynecology, Fertility Center of CHA Gangnam Medical Center, CHA University School of Medicine, 566 Nonhyeon-ro, Gangnam-gu, Seoul, 06135, Korea.
| | - In Pyung Kwak
- Department of Obstetrics and Gynecology, Fertility Center of CHA Gangnam Medical Center, CHA University School of Medicine, 566 Nonhyeon-ro, Gangnam-gu, Seoul, 06135, Korea
| | - Woo Sik Lee
- Department of Obstetrics and Gynecology, Fertility Center of CHA Gangnam Medical Center, CHA University School of Medicine, 566 Nonhyeon-ro, Gangnam-gu, Seoul, 06135, Korea.
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Yazdani A, Halvaei I, Boniface C, Esfandiari N. Effect of cytoplasmic fragmentation on embryo development, quality, and pregnancy outcome: a systematic review of the literature. Reprod Biol Endocrinol 2024; 22:55. [PMID: 38745305 PMCID: PMC11092204 DOI: 10.1186/s12958-024-01217-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 04/01/2024] [Indexed: 05/16/2024] Open
Abstract
The role of cytoplasmic fragmentation in human embryo development and reproductive potential is widely recognized, albeit without standard definition nor agreed upon implication. While fragmentation is best understood to be a natural process across species, the origin of fragmentation remains incompletely understood and likely multifactorial. Several factors including embryo culture condition, gamete quality, aneuploidy, and abnormal cytokinesis seem to have important role in the etiology of cytoplasmic fragmentation. Fragmentation reduces the volume of cytoplasm and depletes embryo of essential organelles and regulatory proteins, compromising the developmental potential of the embryo. While it has been shown that degree of fragmentation and embryo implantation potential are inversely proportional, the degree, pattern, and distribution of fragmentation as it relates to pregnancy outcome is debated in the literature. This review highlights some of the challenges in analysis of fragmentation, while revealing trends in our evolving knowledge of how fragmentation may relate to functional development of the human embryos, implantation, and pregnancy outcome.
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Affiliation(s)
- Ariella Yazdani
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont Medical Center, The Robert Larner College of Medicine at the University of Vermont, Burlington, VT, 05405, USA
- Present address: Obstetrics and Gynecology Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Iman Halvaei
- Department of Anatomical Sciences, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Catherine Boniface
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont Medical Center, The Robert Larner College of Medicine at the University of Vermont, Burlington, VT, 05405, USA
| | - Navid Esfandiari
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont Medical Center, The Robert Larner College of Medicine at the University of Vermont, Burlington, VT, 05405, USA.
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology and Reproductive Sciences, University of Vermont, 111 Colchester Avenue, Burlington, Vermont, 05401, USA.
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Zhang X, Zheng PS. Mechanism of chromosomal mosaicism in preimplantation embryos and its effect on embryo development. J Assist Reprod Genet 2024; 41:1127-1141. [PMID: 38386118 PMCID: PMC11143108 DOI: 10.1007/s10815-024-03048-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 01/30/2024] [Indexed: 02/23/2024] Open
Abstract
Aneuploidy is one of the main causes of miscarriage and in vitro fertilization failure. Mitotic abnormalities in preimplantation embryos are the main cause of mosaicism, which may be influenced by several endogenous factors such as relaxation of cell cycle control mechanisms, defects in chromosome cohesion, centrosome aberrations and abnormal spindle assembly, and DNA replication stress. In addition, incomplete trisomy rescue is a rare cause of mosaicism. However, there may be a self-correcting mechanism in mosaic embryos, which allows some mosaicisms to potentially develop into normal embryos. At present, it is difficult to accurately diagnose mosaicism using preimplantation genetic testing for aneuploidy. Therefore, in clinical practice, embryos diagnosed as mosaic should be considered comprehensively based on the specific situation of the patient.
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Affiliation(s)
- Xue Zhang
- Department of Reproductive Medicine, The First Affiliated Hospital, Xi'an Jiaotong University of Medical School, Xi'an, 710061, Shanxi, P.R. China
| | - Peng-Sheng Zheng
- Department of Reproductive Medicine, The First Affiliated Hospital, Xi'an Jiaotong University of Medical School, Xi'an, 710061, Shanxi, P.R. China.
- Section of Cancer Stem Cell Research, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of People's Republic of China, Xi'an, 710061, Shanxi, P.R. China.
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Martín Á, Mercader A, Beltrán D, Mifsud A, Nohales M, Pardiñas ML, Ortega-Jaén D, de Los Santos MJ. Trophectoderm cells of human mosaic embryos display increased apoptotic levels and impaired differentiation capacity: a molecular clue regarding their reproductive fate? Hum Reprod 2024; 39:709-723. [PMID: 38308811 DOI: 10.1093/humrep/deae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/29/2023] [Indexed: 02/05/2024] Open
Abstract
STUDY QUESTION Are there cell lineage-related differences in the apoptotic rates and differentiation capacity of human blastocysts diagnosed as euploid, mosaic, and aneuploid after preimplantation genetic testing for aneuploidy (PGT-A) based on concurrent copy number and genotyping analysis? SUMMARY ANSWER Trophectoderm (TE) cells of mosaic and aneuploid blastocysts exhibit significantly higher levels of apoptosis and significantly reduced differentiation capacity compared to those of euploid blastocysts. WHAT IS KNOWN ALREADY Embryos diagnosed as mosaic after PGT-A can develop into healthy infants, yet understanding the reasons behind their reproductive potential requires further research. One hypothesis suggests that mosaicism can be normalized through selective apoptosis and reduced proliferation of aneuploid cells, but direct evidence of these mechanisms in human embryos is lacking. Additionally, data interpretation from studies involving mosaic embryos has been hampered by retrospective analysis methods and the high incidence of false-positive mosaic diagnoses stemming from the use of poorly specific PGT-A platforms. STUDY DESIGN, SIZE, DURATION Prospective cohort study performing colocalization of cell-lineage and apoptotic markers by immunofluorescence (IF). We included a total of 64 human blastocysts donated to research on Day 5 or 6 post-fertilization (dpf) by 43 couples who underwent in vitro fertilization treatment with PGT-A at IVI-RMA Valencia between September 2019 and October 2022. A total of 27 mosaic blastocysts were analyzed. PARTICIPANTS/MATERIALS, SETTING, METHODS The study consisted of two phases: Phase I (caspase-3, n = 53 blastocysts): n = 13 euploid, n = 22 mosaic, n = 18 aneuploid. Phase II (terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), n = 11 blastocysts): n = 2 euploid, n = 5 mosaic, n = 4 aneuploid. Following donation for research, vitrified blastocysts were warmed, cultured until re-expansion, fixed, processed for IF, and imaged using confocal microscopy. For each blastocyst, the following cell counts were conducted: total cells (DAPI+), TE cells (GATA3+), inner cell mass (ICM) cells (GATA3-/NANOG+), and apoptotic cells (caspase-3+ or TUNEL+). The incidence of apoptosis was calculated for each blastocyst by dividing the number of caspase-3+ cells (Phase I) or TUNEL+ cells (Phase II) by the number of TE or ICM cells. Statistical analysis was performed according to data type and distribution (P < 0.05 was considered statistically significant). MAIN RESULTS AND THE ROLE OF CHANCE Phase I: Mosaic blastocysts displayed a similar number of total cells (49.6 ± 15 cells at 5 dpf; 58.8 ± 16.9 cells at 6 dpf), TE cells (38.8 ± 13.7 cells at 5 dpf; 49.2 ± 16.2 cells at 6 dpf), and ICM cells (10.9 ± 4.2 cells at 5 dpf; 9.7 ± 7.1 cells at 6 dpf) compared to euploid and aneuploid blastocysts (P > 0.05). The proportion of TE cells retaining NANOG expression increased gradually from euploid blastocysts (9.7% = 63/651 cells at 5 dpf; 0% = 0/157 cells at 6 dpf) to mosaic blastocysts (13.1% = 104/794 cells at 5 dpf; 3.4% = 12/353 cells at 6 dpf) and aneuploid blastocysts (27.9% = 149/534 cells at 5 dpf; 4.6% = 19/417 cells at 6 dpf) (P < 0.05). At the TE level, caspase-3+ cells were frequently observed (39% = 901/2310 cells). The proportion of caspase-3+ TE cells was significantly higher in mosaic blastocysts (44.1% ± 19.6 at 5 dpf; 43% ± 16.8 at 6 dpf) and aneuploid blastocysts (45.9% ± 16.1 at 5 dpf; 49% ± 15.1 at 6 dpf) compared to euploid blastocysts (26.6% ± 16.6 at 5 dpf; 17.5% ± 14.8 at 6 dpf) (P < 0.05). In contrast, at the ICM level, caspase-3+ cells were rarely observed (1.9% = 11/596 cells), and only detected in mosaic blastocysts (2.6% = 6/232 cells) and aneuploid blastocysts (2.5% = 5/197 cells) (P > 0.05). Phase II: Consistently, TUNEL+ cells were only observed in TE cells (32.4% = 124/383 cells). An increasing trend was identified toward a higher proportion of TUNEL+ cells in the TE of mosaic blastocysts (37.2% ± 21.9) and aneuploid blastocysts (39% ± 41.7), compared to euploid blastocysts (23% ± 32.5), although these differences did not reach statistical significance (P > 0.05). LIMITATIONS, REASONS FOR CAUTION The observed effects on apoptosis and differentiation may not be exclusive to aneuploid cells. Additionally, variations in aneuploidies and unexplored factors related to blastocyst development and karyotype concordance may introduce potential biases and uncertainties in the results. WIDER IMPLICATIONS OF THE FINDINGS Our findings demonstrate a cell lineage-specific effect of aneuploidy on the apoptotic levels and differentiation capacity of human blastocysts. This contributes to unravelling the biological characteristics of mosaic blastocysts and supports the concept of clonal depletion of aneuploid cells in explaining their reproductive potential. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by grants from Centro para el Desarrollo Tecnológico Industrial (CDTI) (20190022) and Generalitat Valenciana (APOTIP/2019/009). None of the authors has any conflict of interest to declare. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- Ángel Martín
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
| | - Amparo Mercader
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - Diana Beltrán
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - Amparo Mifsud
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - Mar Nohales
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
| | - María Luisa Pardiñas
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
| | - David Ortega-Jaén
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
| | - María José de Los Santos
- Department of Innovation, IVIRMA Global Research Alliance, IVI Foundation, Health Research Institute La Fe, Valencia, Spain
- Department of Research, IVF Laboratory, IVIRMA Global, Valencia, Spain
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Sobkowiak A, Fluks M, Kosyl E, Milewski R, Szpila M, Tamborski S, Szkulmowski M, Ajduk A. The number of nuclei in compacted embryos, assessed by optical coherence microscopy, is a non-invasive and robust marker of mouse embryo quality. Mol Hum Reprod 2024; 30:gaae012. [PMID: 38407286 PMCID: PMC10978378 DOI: 10.1093/molehr/gaae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 01/15/2024] [Indexed: 02/27/2024] Open
Abstract
Optical coherence microscopy (OCM) visualizes nuclei in live, unlabeled cells. As most cells are uninucleated, the number of nuclei in embryos may serve as a proxy of the cell number, providing important information on developmental status of the embryo. Importantly, no other non-invasive method currently allows for the cell number count in compacted embryos. We addressed the question of whether OCM, by providing the number of nuclei in compacted mouse embryos, may help evaluate embryo quality. We subjected compacted embryonic Day 3 (E3.0: 72 h after onset of insemination) mouse embryos to OCM scanning and correlated nuclei number and developmental potential. Implantation was assessed using an outgrowth assay (in vitro model meant to reflect embryonic ability to implant in vivo). Embryos with more cells at E3.0 (>18 cells) were more likely to reach the blastocyst stage by E4.0 and E5.0 (P ≪ 0.001) and initiate hatching by E5.0 (P < 0.05) than those with fewer cells (<12 cells). Moreover, the number of cells at E3.0 strongly correlated with the total number of cells in E4.0 and E5.0 embryos (ρ = 0.71, P ≪ 0.001 and ρ = 0.61, P ≪ 0.001, respectively), also when only E4.0 and E5.0 blastocysts were considered (ρ = 0.58, P ≪ 0.001 and ρ = 0.56, P ≪ 0.001, respectively). Additionally, we observed a strong correlation between the number of cells at E3.0 and the number of trophectoderm cells in E4.0 and E5.0 blastocysts (ρ = 0.59, P ≪ 0.001 and ρ = 0.57, P ≪ 0.001, respectively). Importantly, embryos that had more cells at E3.0 (>18 cells) were also more likely to implant in vitro than their counterparts with fewer cells (<12 cells; P ≪ 0.001). Finally, we tested the safety of OCM imaging, demonstrating that OCM scanning affected neither the amount of reactive oxygen species nor mitochondrial activity in the embryos. OCM also did not hinder their preimplantation development, ability to implant in vitro, or to develop to term after transfer to recipient females. Our data indicate that OCM imaging provides important information on embryo quality. As the method seems to be safe for embryos, it could be a valuable addition to the current repertoire of embryo evaluation methods. However, our study was conducted only on mouse embryos, so the proposed protocol would require optimization in order to be applied in other species.
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Affiliation(s)
- Aleksandra Sobkowiak
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Monika Fluks
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Ewa Kosyl
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Robert Milewski
- Department of Biostatistics and Medical Informatics, Medical University of Bialystok, Białystok, Poland
| | - Marcin Szpila
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Szymon Tamborski
- Department of Biophotonics and Optical Engineering, Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Torun, Toruń, Poland
| | - Maciej Szkulmowski
- Department of Biophotonics and Optical Engineering, Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Torun, Toruń, Poland
| | - Anna Ajduk
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
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Tonyan ZN, Puppo IL, Saifitdinova AF, Vavilova TV, Glotov AS. Assessment of quadrivalent characteristics influencing chromosome segregation by analyzing human preimplantation embryos from reciprocal translocation carriers. COMPARATIVE CYTOGENETICS 2024; 18:1-13. [PMID: 38298496 PMCID: PMC10825968 DOI: 10.3897/compcytogen.18.115070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/21/2023] [Indexed: 02/02/2024]
Abstract
Patterns of meiotic chromosome segregation were analyzed in cleavage stage and blastocyst stage human embryos from couples with autosomal reciprocal translocations (ART). The influence of quadrivalent asymmetry degree, the presence of terminal breakpoints, and the involvement of acrocentric chromosomes in the rearrangement were analyzed to evaluate their contribution to the formation of non-viable embryos with significant chromosomal imbalance due to pathological segregation patterns and to assess the selection of human embryos by the blastocyst stage. A selection of viable embryos resulting from alternate and adjacent-1 segregation and a significant reduction in the detection frequency of the 3 : 1 segregation pattern were observed in human embryos at the blastocyst stage. The presence of terminal breakpoints increased the frequency of 3 : 1 segregation and was also associated with better survival of human embryos resulting from adjacent-1 mode, reflecting the process of natural selection of viable embryos to the blastocyst stage. The demonstrated patterns of chromosome segregation and inheritance of a balanced karyotype in humans will contribute to optimizing the prediction of the outcomes of in vitro fertilization programs and assessing the risks of the formation of unbalanced embryos for ART carriers.
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Affiliation(s)
- Ziravard N. Tonyan
- D. O. Ott Research Institute of Obstetrics, Gynaecology and Reproductology, 3 Mendeleevskaya Line, 199034, Saint Petersburg, RussiaAlmazov National Medical Research CentreSaint PetersburgRussia
- Almazov National Medical Research Centre, 2 Akkuratova Street, 197341, Saint Petersburg, RussiaD. O. Ott Research Institute of Obstetrics, Gynaecology and ReproductologySaint PetersburgRussia
| | - Irina L. Puppo
- Almazov National Medical Research Centre, 2 Akkuratova Street, 197341, Saint Petersburg, RussiaD. O. Ott Research Institute of Obstetrics, Gynaecology and ReproductologySaint PetersburgRussia
- International Centre for Reproductive Medicine, 53/1 Komendantskij prospect, 197350, Saint Petersburg, RussiaInternational Centre for Reproductive MedicineSaint PetersburgRussia
| | - Alsu F. Saifitdinova
- International Centre for Reproductive Medicine, 53/1 Komendantskij prospect, 197350, Saint Petersburg, RussiaInternational Centre for Reproductive MedicineSaint PetersburgRussia
- Department of Human and Animal Anatomy and Physiology, Herzen State Pedagogical University of Russia, 48 Moyka River Embankment, 191186, Saint Petersburg, RussiaHerzen State Pedagogical University of RussiaSaint PetersburgRussia
| | - Tatyana V. Vavilova
- Almazov National Medical Research Centre, 2 Akkuratova Street, 197341, Saint Petersburg, RussiaD. O. Ott Research Institute of Obstetrics, Gynaecology and ReproductologySaint PetersburgRussia
| | - Andrey S. Glotov
- D. O. Ott Research Institute of Obstetrics, Gynaecology and Reproductology, 3 Mendeleevskaya Line, 199034, Saint Petersburg, RussiaAlmazov National Medical Research CentreSaint PetersburgRussia
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Ezoe K, Takahashi T, Miki T, Kato K. Developmental perturbation in human embryos: Clinical and biological significance learned from time-lapse images. Reprod Med Biol 2024; 23:e12593. [PMID: 38983691 PMCID: PMC11232294 DOI: 10.1002/rmb2.12593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 05/30/2024] [Accepted: 06/07/2024] [Indexed: 07/11/2024] Open
Abstract
Background Time-lapse technology (TLT) has gained widespread adoption worldwide. In addition to facilitating the undisturbed culture of embryos, TLT offers the unique capability of continuously monitoring embryos to detect spatiotemporal changes. Although these observed phenomena play a role in optimal embryo selection/deselection, the clinical advantages of introducing TLT remain unclear. However, manual annotation of embryo perturbation could facilitate a comprehensive assessment of developmental competence. This process requires a thorough understanding of embryo observation and the biological significance associated with developmental dogma and variation. This review elucidates the typical behavior and variation of each phenomenon, exploring their clinical significance and research perspectives. Methods The MEDLINE database was searched using PubMed for peer-reviewed English-language original articles concerning human embryo development. Main findings TLT allows the observation of consecutive changes in embryo morphology, serving as potential biomarkers for embryo assessment. In assisted reproductive technology laboratories, several phenomena have not revealed their mechanism, posing difficulties such as fertilization deficiency and morula arrest. Conclusion A profound understanding of the biological mechanisms and significance of each phenomenon is crucial. Further collaborative efforts between the clinical and molecular fields following translational studies are required to advance embryonic outcomes and assessment.
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Hur C, Nanavaty V, Yao M, Desai N. Correction to: The presence of partial compaction patterns is associated with lower rates of blastocyst formation, sub‑optimal morphokinetic parameters and poorer morphologic grade. Reprod Biol Endocrinol 2023; 21:63. [PMID: 37443021 DOI: 10.1186/s12958-023-01117-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/15/2023] Open
Affiliation(s)
- Christine Hur
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Women's Health Institute, Cleveland Clinic, 26900 Cedar Road, Beachwood, OH, 44122, USA.
| | - Vaani Nanavaty
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Women's Health Institute, Cleveland Clinic, 26900 Cedar Road, Beachwood, OH, 44122, USA
| | - Meng Yao
- Quantitative Health Sciences, Cleveland Clinic, 9500 Euclid Ave. JJN3, Cleveland, OH, 44195, USA
| | - Nina Desai
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Women's Health Institute, Cleveland Clinic, 26900 Cedar Road, Beachwood, OH, 44122, USA
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