Relative kinetic expressions defining cleavage synchronicity are better predictors of blastocyst formation and quality than absolute time points

Abstract

PurposeMorphology alone is not enough for the selection of the embryo (s) with the highest implantation potential and time-lapse imaging has added embryo development kinetics as another selection criterion. Therefore, a combination of morphology with kinetics has inspired a new field termed “morphokinetics”, providing a new way of evaluating and selecting embryos. The aim of the study was to identify a criterion solely based on morphokinetic data and available up to the 8-cell stage (t8) to predict blastocyst formation and quality.MethodsThe study included 3,354 embryos, with annotations up to t8, and cultured until day 5 from 626 infertile patients. A total of 17 kinetic expressions, either absolute cleavage timings and time intervals or time ratios were tested retrospectively for the prediction of blastocyst formation and quality.ResultsRelative timings (t8-t5, the cleavage synchronicity from 4 to 8 cells and from 2 to 8 cells) were found to be better indicators of blastocyst formation and quality when compared to absolute time-points. Especially, the cleavage synchronicity from 2 to 8 cells (CS2-8) = ((t3-t2) + (t5-t4))/(t8-t2)) was found to be the best predictor available on day 3 for blastocyst formation and quality (AUC:0.786; sensitivity: 83.43; specificity: 62.46).ConclusionsTime intervals and relative ratios based on selected cleavage cycles defining synchronicity allowed a specific analysis providing high predictivity of blastocyst formation and quality.Electronic supplementary materialThe online version of this article (doi:10.1007/s10815-014-0341-x) contains supplementary material, which is available to authorized users.

Decrease in bovine in vitro embryo production efficiency during winter season in a warm-summer Mediterranean climate

“…In contrast, higher embryo production was obtained in autumn and spring. These results support the cleavage rate as a good predictor of the in vitro blastocyst development (Cetinkaya et al., ; Fu et al., ). Accordingly, the results show a significant decrease in cleavage rates and blastocyst production during winter, corroborating our hypothesis.…”

Morphokinetics of embryos developed from oocytes matured in vitro

“…As mentioned above, longer s2 intervals (i.e., reduced synchrony) have been hypothesized to be associated to reduced implantation rates [13]. It was also observed that time intervals and relative ratios defining synchronicity are highly predictive of blastocyst development and quality [28]. Therefore, the difference in s2 emerged in our study from the comparison of embryos generated in IVM and stimulated cycles should not be overlooked but rather further investigated.…”

Do morphokinetic data sets inform pregnancy potential?

“…Aparicio et al claim that important improvements in embryo selection may be realized using time-lapse technology because of the possibility of selecting viable embryos with a high developmental potential [ 3 ]. Cetinkaya et al present an itemized comparative analysis of kinetic parameters focusing on relative time ratios and time intervals [ 4 ]. They produced an equation based on analyzed morphokinetic variables, allowing for the prediction of blastocyst formation.…”