Cleavage Stage at Compaction – A Good Predictor for IVF Outcome
2Department of Cell Biology and Development, Sackler Faculty of Medicine & Sagol School of Neuroscience, Tel-Aviv University, Israel
Purpose:
Selecting which embryo to transfer is a significant challenge in IVF. The aim of this study was to anaylze wether cleavage stage at compaction, and not only kinetics, can serve as a reliable predictor for clinical outcome.
Methods:
A total of 815 IVF embryos (175 cycles) grown in our lab during 2016-2017 were classified by compaction initiation stage (Group 1: compaction at 8 cells (n=689). Morphokinetic parameters were also annotated. For clinical validation of the embryo results, all single blastocyst thawn and transfered during years 2017-2019 were also included (379 embryos).
Results:
In total, 1194 embryos were included in the analysis. Embryos that underwent compaction from >8 cells (Group 3) exhibited significantly more synchronous cleavage compared to Groups 1 & 2 (at both S2 and S3; p<0.0001), and displayed a significantly lower fragmentation rate. The likelihood of obtaining top-quality blastocysts decreased by 73% and 44% when comparing Group 3 embryos with those of Group 1 and 2 respectively (p<0.03). Most importantly, our clinical validation of the results shows that compaction at ≥8 cell is crucial for implantation and for ending with a live birth (birth rate 11.1% & 18.5% for groups 2 & 3 respectively), compared to those compacting from
Conclusion:
Cleavage stage at compaction has a direct effect on blastocyst quality and most probably on subsequent pregnancy outcome. Hence should be included in the newly developed deep learning models for embryo selection