Prediction of the in vitro developmental competence of early‐cleavage‐stage human embryos with time‐lapse imaging and oxygen consumption rate measurement

Abstract

PurposeTo assess an embryo's ability to develop into a good‐quality blastocyst during the early‐cleavage stage using time‐lapse imaging and the oxygen consumption rate.MethodsIn total, 942 zygotes had their oxygen consumption rates measured. In total, 282 zygotes were assessed by using time‐lapse imaging. In total, 121 zygotes were examined by using both their oxygen consumption rate and time‐lapse imaging.ResultsThe embryos with moderate respiration rates of between 0.41 and 0.61 (×1014/mol s−1) on day 3 had a 22.1% chance of becoming good‐quality blastocysts; those outside that range had a 14.3% chance. With the time‐lapse system, when the first division was within 24 hours, 22.3% of the embryos grew to good blastocysts. After 24 hours, the rate dropped to 8.6%. The intervals between two consecutive cleavages were calculated and the duration of the second cell cycle was defined. When the time was between nine hours and 13 hours, there was a higher rate of good blastocysts. Regarding both criteria, when the embryos had progressed in the optimal range, a high percentage of them had become good blastocysts; it was 8.0% outside of that range.ConclusionIndividual embryos with the potential to develop into good‐quality blastocysts could be selected at day 3 of culture using these systems.

Application of extracellular flux analysis for determining mitochondrial function in mammalian oocytes and early embryos

“…Mitochondrial oxidative phosphorylation, measured as the oxygen consumption rate (OCR) 14 , is the largest contributor to cellular ATP demand during preimplantation development 12,15,16 . A number of techniques have been used to measure OCR in oocytes and embryos, including the Cartesian diver 17 , microspectrophotometry 18 , pyrene ultramicrofluorescence 10,11 , scanning electron microscopy 19,20 and micro-respirometry 21,22 . Combined, these approaches have been instrumental in defining the overall metabolism of oocytes and early embryos, and have yielded remarkably consistent data.…”

“…Combined, these approaches have been instrumental in defining the overall metabolism of oocytes and early embryos, and have yielded remarkably consistent data. Importantly, OCR of mammalian embryos has been reported to correlate with reproductive physiological outcomes including oocyte maturation 23 , embryo morphology 13,19,20 , implantation potential 24 , and pregnancy rate 13 . Generally, ‘mid-range’ or ‘Goldilocks-range’ OCR values are associated with higher oocyte/embryo quality and viability 25 .…”

Preimplantation genetic testing: A remarkable history of pioneering, technical challenges, innovations, and ethical considerations

“…Oxygen consumption measurements, metabolic measurement of embryo culture media, and hyperspectral microscopy are among the other potential tools for embryo assessment but require further testing (Houghton et al, 1996;Krisher et al, 2015;Kurosawa et al, 2016;Sutton-McDowall et al, 2017). Oxygen consumption may not correlate completely with blastocyst quality (Kurosawa et al, 2016) but measuring oxygen consumption along with morphological imaging can be effective at selecting for embryo quality (Tejera et al, 2012(Tejera et al, , 2016 and embryos competent to undergo blastocyst formation (Goto et al, 2018). The emergence of methods combining AI with image and video data as well as innovations in determining oxygen consumption patterns may provide valuable data to accompany PGT data in selecting embryos for transfer.…”

Are we approaching automated assisted reproductive technology? Embryo culture, metabolomics, and cryopreservation

“…Another recent study from Goto et al (67) analyzed OC, measured with the use of scanning electrochemical microscopy, in relation to time-lapse imaging and found that moderate oxygen consumption rate on day 3 was associated with good-quality blastocysts.…”