Blastomere cleavage plane orientation and the tetrahedral formation are associated with increased probability of a good-quality blastocyst for cryopreservation or transfer: a time-lapse study.
OBJECTIVE
To determine whether blastomere spatial arrangement in early human embryos is reflective of embryonic potential.


DESIGN
Retrospective analysis of prospectively collected data.


SETTING
Single academic center.


PATIENT(S)
Patients undergoing a single blastocyst transfer.


INTERVENTION(S)
None.


MAIN OUTCOME MEASURE(S)
Developmental kinetics, blastocyst quality, embryo dysmorphisms, and live birth rate.


RESULT(S)
A total of 716 embryos were examined in detail for cleavage plane orientation, blastomere arrangement, and morphokinetic behavior. Tetrahedral (TET) and nontetrahedral embryos (nTET) differed significantly in developmental kinetics. The frequency of dysmorphisms, multinucleation, and irregular chaotic division was higher in nTET embryos. Only 44% of nTET versus 62.9% of TET embryos were scored as top-quality blastocysts. After adjusting for age, our data indicated that having TET embryos significantly increased the odds of having a blastocyst for cryopreservation/transfer (odds ratio, 3.58; confidence interval, 2.42-5.28) when compared with nTET. A total of 164 fresh single ETs were performed with blastocyst-stage embryos. The implantation rate for TET- and nTET-derived blastocysts were similar (64.7% and 62%, respectively). The live birth rate was 55% in both groups. A meridonal first division was noted in 85% of the fresh SET blastocysts.


CONCLUSION(S)
Cleavage plane orientation during the first three divisions appeared to dictate final blastomere spatial arrangement. The TET formation at the four-cell stage was predictive for embryos most likely to develop into good-quality blastocysts for cryopreservation/transfer. Morphokinetic markers of embryo potential were significantly different between TET and nTET embryos.
['Desai|Nina|N|', 'Gill|Pavinder|P|']
D000328:Adult D001757:Blastomeres D015925:Cryopreservation D004624:Embryo Transfer D047108:Embryonic Development D005260:Female D005298:Fertility D006801:Humans D007246:Infertility D007700:Kinetics D050498:Live Birth D018715:Microscopy, Video D011247:Pregnancy D018873:Pregnancy Rate D012189:Retrospective Studies D018570:Risk Assessment D012307:Risk Factors D059008:Time-Lapse Imaging D016896:Treatment Outcome
morphokinetics Planar embryos spatial arrangement and multinucleation time-lapse imaging