Blastulation time measured with time-lapse system can predict in vitro viability of bovine blastocysts

Abstract

The objective of this study was to evaluate the time of blastulation monitored by time-lapse technology to predict in vitro viability of bovine blastocysts. This technology can be a powerful tool for bovine embryos selection with higher implantation capacity and competence. Also, in humans an early blastulation is associated with higher quality and pregnancy rate. Cumulus oocyte complexes (COCs) were matured for 20 to 22 h and then fertilized by co-incubation of COCs and spermatozoa (10,000 sperm per oocyte) for 18 h. Presumptive zygotes were placed individually in microwells, in droplets of commercial culture medium. The Primo Vision TL system (EVO+; Vitrolife) captured digital images of developing embryos every 15 minutes. The time frame from IVF to the start of blastulation (tSB) and to blastocyst development (tB) was recorded. After day 7.5, the blastocysts were in vitro culture for 48 h until day 9.5 after IVF to evaluate post hatching development. In vitro viability was evaluated at day 9.5: those with a diameter greater than 200 μm and a total cell count greater than 180 were classified as viable (value 1), while the rest were classified as non in vitro viable (value 0). The area under the ROC curve (AUC) was estimated to determine the predictive power of in vitro viability through blastulation time. In addition, binary logistic regression analysis was used to generate a mathematical model with morphokinetic variables that allow the best prediction of in vitro viability. In 13 sessions, the blastocyst production rate was 46.2% (96/208). The cut-off time to discriminate early or late blastulation was 149.8 h. The post-hatching development of the embryos with early blastulation was 63.3% (31/49), being statistically superior (p = 0.001) than the late blastulation group 14.9% (7/47). Likewise, the time of blastulation showed an accuracy of 90.8% (p < 0.001) in predicting in vitro viability of bovine blastocysts. In conclusion, the selection of blastocysts based on blastulation time (< 155 h) and blastocyst diameter measured on day 7.5 after IVF (> 180 μm) maximizes the in vitro viability.

The Effect of Artificial Oocyte Activation on Embryomorphokinetic Parameters and Blastulation Time

“…However, in contrast to their ndings, in our study pronuclei transformation or third cell cycle synchronization were not different and we found a prolonged tb in AOA cycles. Research on humans has highlighted the potential of tb as a determining factor for selecting embryos, surpassing other components of embryo morphological grading [35][36][37]. Lee et al and Moustafa et al noted delayed tb in embryos with chromosome abnormalities [36,38].…”

Correction: Blastulation time measured with time-lapse system can predict in vitro viability of bovine blastocysts

“…After publication of this article [ 1 ], concerns were raised that Fig 2 in [ 1 ] was duplicated from Figure 3 in a previous article [ 2 ] by a different author group, and that [ 2 ] was not cited in [ 1 ].…”

“…During editorial follow up on this issue, the corresponding author stated that Fig 2 in [ 1 ] was included in error.…”

“…Owing to the concerns about duplication with previously published content [ 2 ], published in 2010 by Oxford University Press [ 2 ], which is not offered under a CC BY license, this article [ 1 ] was republished on June 24, 2024, to correct the Fig 2 error. The updated figure reports demonstrative images of individual cultures in 16 microwell plates to monitor embryonic development in cattle.…”

“…The updated figure reports demonstrative images of individual cultures in 16 microwell plates to monitor embryonic development in cattle. These images are from the original experiments reported in [ 1 ] at day 7.5 post IVF ( S5 File ). Replicate images from the time of the original experiments and images from earlier and later repeat experiments are provided here in S1 – S4 Files.…”