Background: The assisted reproductive technologies continue to improve in both techniques and results. The goal to achieve better clinical pregnancy rates by using time-lapse video cinematography as a non-invasive selected embryo transfer method, now under investigation.
Objective: This study aims to verify the morphokinetic criteria to discriminate good morphological blastocyst (group I) from poor morphological blastocyst (group II) by using Primo vision® (Vitrolife, Sweden).
Material and Method: The prospective study was performed in infertile couples treated with assisted reproductive technology at Thammasat Fertility Center, Thailand, in 2015. The morphokinetic study was compared between the two groups by t-test and Mann-Whitney U test with p<0.05 as statistical significance.
Results: Total of 63 blastocysts from 20 infertile couples was included. Thirty-three good quality blastocysts (52.38%) in group I and 30 poor quality blastocysts (47.62%) in group II were under morphokinetic study. T5 and CC3 were longer in group I compared to those in group II (mean = 51.85 and 15.04 vs. 47.98 and 12.42 hours, p = 0.03 and 0.04, respectively). Tm of group I was shorter than group II (mean = 88.16 vs. 96.64 hours, p = 0.00), Tb and S2 were also shorter in group I compared to those in group II (median = 109.50 and 1.00 vs. 118.19 and 1.95 hours, p = 0.00 and 0.02, respectively).
Conclusion: T5, CC3 and S2 of cleavage stage could be used to predict the quality of blastocyst. Tm and Tb of blastocyst stage are also useful in good quality blastocyst selection.

Keywords: Morphokinetic criteria, Cleavage stage embryo, Blastocyst stage embryo, Time-lapse embryoscope, Assisted
reproductive technology