Time-lapse imaging provides further evidence that planar arrangement of blastomeres is highly abnormal
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Recently, guidelines on the annotation of dynamic human embryo monitoring recommended screening for the presence of planar blastomere arrangement at the 4-cell stage. This observational study was set up in order to analyze whether developmental kinetics of planar human embryos are different from tetrahedral ones.
Therefore, embryos of 115 consecutive ICSI patients (showing 32 planar and 554 tetrahedral embryos) were cultured in a new time-lapse system (Miri TL) and their embryos were annotated for morphokinetic development and screened for irregular cleavages and morphological dysmorphisms.
Significantly less planar embryos reached blastocyst stage and showed worse quality as compared to regular tetrahedral embryos. The rate of bi- and/or multinucleation was also significantly higher in the affected group. Irregular cleavages, particularly embryo rolling, were more often seen in planar embryos. Morphokinetics between planar and tetrahedral were distinguishable up to 4-cell stage (t2–t4), thereafter the observed delay in planar embryos (t8) was more likely the result of a higher rate of arrested embryos in the planar group.
Planar embryos are associated with both a significant increase in irregular cleavage as well as a delay in preimplantation development. This indicates that planar embryos are rather abnormal and should only be considered for transfer if no other embryos are available.
KeywordsPlanar embryos Time-lapse imaging Morphokinetics Multinucleation Irregular cleavage
The authors would like to thank G. Schappacher-Tilp for statistical expertise.
TE: manuscript writing, data management. AH: data collection. PO: data management, manuscript editing. ER: manuscript editing. SHE: data collection. RBM: data collection. EP: protocol development, data analysis. OS: manuscript editing, project development.
Compliance with ethical standards
To ensure objectivity and transparency in research it is stated that no funding was received for this study.
Conflict of interest
None of the authors/coauthors declared a conflict of interest related to this study.
As mentioned in the “Methods” section time-lapse technology in our lab is routinely applied, therefore we refrained from applying for IRB approval for the present observational study.
Patients gave informed consent and were not charged for time-lapse imaging. In no case affected embryos were transferred. No animals were involved.
Video 1. Planar arrangement of cells. It should be noted that oocyte presents 1PN between 14h and 30h before 2Pn formed (35h). t2 (44.8h), t3 (57.8h), and t4 (58.5h) are delayed and embryo development stopped at 6-cell stage (MP4 17760 kb)
Video 2. Regularly fertilized zygote (2Pn) resulting in planar arrangement of cells (43.4h). At 112.6h early morula stage is reached upon which development stopped (MP4 38041 kb)
- 1.Wirleitner B, Schuff M, Stecher A, Murtinger M, Vanderzwalmen P (2016) Pregnancy and birth outcomes following fresh or vitrified embryo transfer according to blastocyst morphology and expansion stage, and culturing strategy for delayed development. Hum Reprod 31:1685–1695CrossRefPubMedGoogle Scholar
- 10.Alpha Scientists in Reproductive Medicine, ESHRE Special Interest Group of Embryology (2011) The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting. Reprod Biomed Online 22:632–646Google Scholar
- 11.Rhenman A, Berglund L, Brodin T, Olovsson M, Milton K, Hadziosmanovic N et al (2015) Which set of embryo variables is most predictive for live birth? A prospective study in 6252 single embryo transfers to construct an embryo score for the ranking and selection of embryos. Hum Reprod 30:28–36CrossRefPubMedGoogle Scholar
- 19.Liu Y, Chapple V, Roberts P, Matson P (2014) Prevalence, consequence, and significance of reverse cleavage by human embryos viewed with the use of the embryoscope time-lapse video system. Fertil Steril 102(1295–1300):e2Google Scholar
- 23.Liu Y, Chapple V, Roberts P, Matson P (2015) Clinical significance of intercellular contact at the four-cell stage of human embryos, and the use of abnormal cleavage patterns to identify embryos with low implantation potential: a time-lapse study. Fertil Steril 103(1485–1491):e1Google Scholar
- 37.Ergin EG, Calişkan E, Yalçinkaya E, Oztel Z, Cökelez K, Ozay A et al (2014) Frequency of embryo multinucleation detected by time-lapse system and its impact on pregnancy outcome. Fertil Steril 102(1029–1033):e1Google Scholar
- 38.Balakier H, Sojecki A, Motamedi G, Librach C (2016) Impact of multinucleated blastomeres on embryo developmental competence, morphokinetics, and aneuploidy. Fertil Steril 106(608–614):e2Google Scholar
- 40.Yang Z, Zhang J, Salem SA, Liu X, Kuang Y, Salem RD et al (2014) Selection of competent blastocysts for transfer by combining time-lapse monitoring and array CGH testing for patients undergoing preimplantation genetic screening: a prospective study with sibling oocytes. BMC Med Genom 7:38CrossRefGoogle Scholar
- 42.Kramer YG, Kofinas JD, Melzer K, Noyes N, McCaffrey C, Buldo-Licciardi J et al (2014) Assessing morphokinetic parameters via time lapse microscopy (TLM) to predict euploidy: are aneuploidy risk classification models universal? J Assist Reprod Genet 31:1231–1242CrossRefPubMedPubMedCentralGoogle Scholar
- 43.Rienzi L, Capalbo A, Stoppa M, Romano S, Maggiulli R, Albricci L et al (2015) No evidence of association between blastocyst aneuploidy and morphokinetic assessment in a selected population of poor-prognosis patients: a longitudinal cohort study. Reprod Biomed Online 30:57–66CrossRefPubMedGoogle Scholar