Combination of metabolism measurement and a time-lapse system provides an embryo selection method based on oxygen uptake and chronology of cytokinesis timing.

OBJECTIVE: To evaluate correlations between oxygen consumption (OC) measurements before and after embryo cytokinesis, observing OC during embryo cleavages and combining that information with morphokinetics to relate to implantation potential.
DESIGN: Prospective cohort study.
SETTING: University-affiliated private IVF unit. PATIENT(S): A total of 1,150 injected oocytes in 86 first oocyte donation cycles with embryo transfer on day 3. INTERVENTION(S): None. MAIN OUTCOME MEASUREMENT(S): We analyzed the embryo OC and combined this data with the cytokinesis event, exact timing (in hours) of blastomeric cleavages, with the use of an incubator equipped with time-lapse videography, gathering a total of 7,630 measurements during the cytokinesis (active phase) and consecutive measurements after this division (passive phase), correlating this data with embryo outcome. RESULT(S): OC was found to increase during embryo cleavage, showing high levels during first division with a strong correlation with implantation success. Moreover, those embryos with slow or fast development gave rise to lower OC levels, whereas higher levels were associated with optimal embryo division ranges linked to higher implantation potential. CONCLUSION(S): A detailed analysis of OC by time-lapse observations enhances the value that these measurements represented as markers of embryo quality, especially during the cytokinesis events produced during preimplantation development.