Prediction of blastocyst development and implantation potential <i>in utero</i> based on the third cleavage and compaction times in mouse pre-implantation embryos

Abstract

Cytokinesis and cell division during pre-implantation embryonic development occur as an orchestrated spatiotemporal program. Cleavage, compaction, and blastulation in pre-implantation embryos are essential for successful implantation and pregnancy. Their alteration is associated with chromosomal imbalance and loss of developmental competence. In this study, we evaluated the time of cleavage and compaction as predictors for in vitro pre- and peri-implantation development and in utero implantation potential by time-lapse monitoring. Mouse 2-cell embryos were collected on 1.5 days post coitum (dpc) and were individually cultured to the outgrowth (OG) stage (7.5 dpc). Developmental stages were classified as 3-cell, 4-cell, 8-cell, morula, blastocyst, and OG. Cut-off times for successful blastocyst development were determined by receiver operating characteristic curve analysis. When cut-off times were set as 9 h for the third cleavage from the 2- to 4-cell stage, and 40 h for compaction from the 2-cell to morula stage, blastocyst and OG development rates, respectively, were significantly higher (P < 0.0001). Embryos were grouped according to the above cut-off time and transferred to the contralateral uterine horn on 3.5 dpc. Implantation rates in utero on 5.5 dpc were significantly higher in early third cleaved (≤ 9 h from 2- to 4-cell) and early compacted embryos (≤ 40 h from 2-cell to morula) than those in delayed embryos (P < 0.05). Therefore, the time of the third cleavage from 2- to the 4-cell stage and compaction from 2-cell to morula stage may be a useful morphokinetic parameter for predicting developmental potential, including successful implantation and pregnancy in human in vitro fertilization-embryo transfer programs.

Are cleavage anomalies, multinucleation, or specific cell cycle kinetics observed with time-lapse imaging predictive of embryo developmental capacity or ploidy?

“…Time-lapse (TL) imaging of developing embryos offers more accurate quantification of cellular kinetics and cell cycle events than was possible with conventional static morphology assessment. A wide array of kinetic markers have been proposed to be predictive for continued embryonic development and blastocyst formation (8,(10)(11)(12)(13)(14)(15)(16). TL has also revealed the prevalence of specific dysmorphisms such as multinucleation (MU), reverse cleavage (RC), direct uneven cleavage (DUC), and irregular chaotic division (ICD) in human preimplantation embryos (10,(17)(18)(19)(20).…”

Advantages of the outgrowth model for evaluating the implantation competence of blastocysts

“…In our previous studies, we confirmed a correlation in the developmental competence of preimplantation embryos between blastocyst outgrowth in vitro and implantation in utero [42,43]. We established a novel coculture system with outgrowth and preimplantation embryos, and investigated how this coculture system improved preimplantation and peri-implantation embryonic development both in vitro and in utero.…”

“…A time-lapse monitoring system has been applied to select transferrable embryos and to predict the developmental competence of preimplantation embryos in human IVF-ET programs. We studied blastocyst development and implantation potential in utero based on the third cleavage and compaction times using a mouse model [43]. Our results provided evidence that analyzing morphokinetics by a time-lapse monitoring system may improve the efficacy of selection of transferrable embryos with high implantation potential in human IVF-ET programs.…”

“…Our results provided evidence that analyzing morphokinetics by a time-lapse monitoring system may improve the efficacy of selection of transferrable embryos with high implantation potential in human IVF-ET programs. In that study, we found that the times of the third cleavage to the four-cell stage and compaction to the morula stage were useful morphokinetic parameters for predicting the potential of mouse preimplantation embryos to develop into outgrowth in vitro and implantation in utero [43].…”

Effects of dynamic oxygen concentrations on the development of mouse pre- and peri-implantation embryos using a double-channel gas supply incubator system

“…Aspects of the in vitro trophoblastic outgrowth model, such as activation and spread, are related to proliferation and invasion in in vivo implantation processes [40][41][42][43]. In addition, morphokinetics and metabolism, as evidenced by the trophoblastic outgrowth assay, are correlated with viability and implantation potential [44,45]. In this study, the outgrowth rate after 3 days of culture of blastocysts in the dynamic-O2 (5% to 2%) and low-O2 (5%) groups was superior to that in the high-O2 (20%) group.…”