Preliminary morphokinetic annotation data for early equine embryo development in vitro using a time-lapse imaging system

2016 ◽  
Vol 41 ◽  
pp. 72
Author(s):  
Karen Schnauffer ◽  
Niamh Lewis ◽  
Stephen Troup ◽  
Dai Grove-White ◽  
Caroline McG. Argo
2019 ◽  
Vol 31 (12) ◽  
pp. 1851 ◽  
Author(s):  
Niamh Lewis ◽  
Karen Schnauffer ◽  
Katrin Hinrichs ◽  
Monica Morganti ◽  
Stephen Troup ◽  
...  

The use of time-lapse imaging (TLI) in the evaluation of morphokinetics associated with invitro developmental competence is well described for human, cattle and pig embryos. It is generally accepted that embryos that complete early cleavage sooner are more likely to form blastocysts and that timing of later events, such as blastocyst formation and expansion, are predictive of implantation potential and euploid status. In the horse, morphokinetics as a predictor of developmental competence has received little attention. In this study we evaluated the morphokinetics of early equine embryo development invitro for 144 oocytes after intracytoplasmic sperm injection and report the timings of blastocyst development associated with ongoing pregnancy for the first time. There was a tendency for time of cytoplasmic extrusion and first cleavage to occur earlier in the embryos that went on to form blastocysts (n=19) compared with those that arrested, and for first cleavage to occur earlier in blastocysts that established pregnancies that were ongoing (n=4) compared with pregnancies that were lost (n=2). TLI was clinically useful in identifying blastocysts when evaluation of morphology on static imaging was equivocal.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 748
Author(s):  
Joanna Kochan ◽  
Agnieszka Nowak ◽  
Barbara Kij ◽  
Sylwia Prochowska ◽  
Wojciech Niżański

The aim of this study was to analyze the morphokinetic parameters of feline embryos using a time lapse system. Oocytes matured in vitro were fertilized (IVF) and in vitro cultured in a time lapse-system (Primo Vision®, Gothenburg, Sweden). The first cell division of embryos occurred between 17 h post insemination (hpi) and 38 hpi, with the highest proportion of embryos (46%) cleaving between 21 and 24 hpi. The timing of the first cleavage significantly affected further embryo development, with the highest development occurring in embryos that cleaved at 21–22 hpi. Embryos that cleaved very early (17–18 hpi) developed poorly to the blastocyst stage (2%) and none of the embryos that cleaved later than 27 hpi were able to reach the blastocyst stage. Morphological defects were observed in 48% of the embryos. There were no statistically significant differences between the timing intervals of the first cleavage division and the frequency of morphological defects in embryos. Multiple (MUL) morphological defects were detected in more than half (56%) of the abnormal embryos. The most frequent single morphological defects were cytoplasmic fragmentation (FR) (8%) and blastomere asymmetry (AS) (6%). Direct cleavage (DC) from 1–3 or 3–5 blastomeres, reverse cleavage (RC) and vacuoles were rarely observed (2–3%). The timing of blastocyst cavity formation is a very good indicator of embryo quality. In our study, blastocyst cavity formation occurred between 127–167 hpi, with the highest frequency of hatching observed in blastocysts that cavitated between 142–150 hpi. Blastocysts in which cavitation began after 161 h did not hatch. In conclusion, the timing of the first and second cleavage divisions, the timing of blastocyst cavity formation and morphological anomalies can all be used as early and non-invasive indicators of cat embryo development in vitro.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
M Sugishima ◽  
K Yumoto ◽  
T Shimura ◽  
Y Mio

Abstract Study question Is it possible to culture ZP-free embryos to eliminate perivitelline threads, which are known to be involved in generating cytoplasmic fragments at the first cleavage? Summary answer ZP-free culturing, an innovative system that decreases the amount of cytoplasmic fragments without disrupting the blastomeres, using incubators with time-lapse imaging. What is known already A study in 2017 observed perivitelline threads in more than 50% of cleavage-stage human embryos using time-lapse imaging, and the rate of cytoplasmic fragmentation (at the first cleavage) was significantly decreased in embryos without perivitelline threads (P < 0.001). While it has been proposed that perivitelline threads play an important role in crosslinking the cumulus cells and oocyte during maturation, the mechanism underlying such a role remains unclear. It is also unknown whether the threads still function in mature MII oocytes. Study design, size, duration A prospective study was conducted using 2,852 normal (2PN/2PB) embryos from c-IVF/ICSI and 113 abnormal (3PN) embryos obtained from c-IVF between 2017 and 2019. The zona pellucida (ZP) of 71 abnormal embryos was removed at the pronuclear stage (“ZP-free”), and the rest (n = 42) were cultured as “ZP-intact”. Normal and abnormal embryos were cultured for five days in bench-top incubators (MINC, COOK) and an incubator equipped with a time-lapse imaging system. Participants/materials, setting, methods Embryos used in this study were donated by 412 couples who underwent c-IVF cycles in our clinic between 2017 and 2019. For ZP removal, 3PN embryos were placed in 0.125M sucrose-containing HEPES media drops to reduce the ooplasm size. Then, ooplasms were completely separated from ZPs by a laser and pipetting. Embryo development and morphology of the three groups (normal, ZP-intact and ZP-free abnormal) were compared based on the degree of cytoplasmic fragmentation. Main results and the role of chance The first cleavage occurred in 97.8% (n = 2,790/2,852) of 2PN/2PB, 83.3% (n = 35/42) of ZP-intact 3PN and 97.2% (n = 69/71) of ZP-free 3PN. Normal (2PN/2PB), ZP-intact and ZP-free 3PN embryos were classified into three groups based on the modified Veeck’s criteria thus: <20% fragmented compared to the total volume of cytoplasm at the first cleavage (Grade 1 and 2, Good); 20–39% fragmented (Grade 3, Fair) and ≧40% fragmented (Grade 4, Poor). Of 69 cleaved ZP-free 3PN embryos, 68.1% (n = 47) showed less than 20% fragments which was significantly higher than 2PN/2PB (43.7%, n = 1,218/2,790) and ZP-intact 3PN (45.7%, n = 16/35; P < 0.05). Furthermore, 24.6% (n = 17/69) of ZP-free 3PN embryos showed 20–39% fragments which was significantly lower than 2PN/2PB (45.9%, n = 1,281/2,790; P < 0.05). In addition, 50.7% of ZP-free 3PN embryos (n = 36) developed to the morula stage after the third cleavage, and 29.6% (n = 21) formed blastocoel and became blastocysts. Thus, removing the ZP before the first cleavage did not adversely affect embryo development and decreased the cytoplasmic fragmentation. Limitations, reasons for caution Due to ethical and clinical limitations, we only examined abnormally fertilized embryos in this study. Moreover, since the relationship between the perivitelline threads and cytoplasmic fragments is unclear, we plan to conduct molecular biological analysis of the perivitelline threads in further studies. Wider implications of the findings: This study revealed that ZP is not always necessary after the pronuclear stage because ZP-free embryos studied herein developed normally and maintained cell adhesion well. This innovative culture method might provide the breakthrough needed for patients to improve embryo quality who obtain embryos with severe fragmentation caused by perivitelline threads. Trial registration number Not applicable


2019 ◽  
Vol 31 (12) ◽  
pp. 1862 ◽  
Author(s):  
N. A. Martino ◽  
G. Marzano ◽  
A. Mastrorocco ◽  
G. M. Lacalandra ◽  
L. Vincenti ◽  
...  

Time-lapse imaging was used to establish the morphokinetics of equine embryo development to the blastocyst stage after invitro oocyte maturation (IVM), intracytoplasmic sperm injection (ICSI) and embryo culture, in oocytes held overnight at room temperature (22–27°C; standard conditions) before IVM. Embryos that developed to the blastocyst stage underwent precleavage cytoplasmic extrusion and cleavage to the 2-, 3- and 4-cell stages significantly earlier than did embryos that arrested in development. We then determined the rate of blastocyst formation after ICSI in oocytes held for 2 days at either 15°C or room temperature before IVM (15-2d and RT-2d treatment groups respectively). The blastocyst development rate was significantly higher in the 15-2d than in the RT-2d group (13% vs 0% respectively). The failure of blastocyst development in the RT-2d group precluded comparison of morphokinetics of blastocyst development between treatments. In any condition examined, development to the blastocyst stage was characterised by earlier cytoplasmic extrusion before cleavage, earlier cleavage to 2- and 4-cell stages and reduced duration at the 2-cell stage compared with non-competent embryos. In conclusion, this study presents morphokinetic parameters predictive of embryo development invitro to the blastocyst stage after ICSI in the horse. We conclude that time-lapse imaging allows increased precision for evaluating effects of different treatments on equine embryo development.


2019 ◽  
Vol 101 (6) ◽  
pp. 1146-1154 ◽  
Author(s):  
Raquel Del Gallego ◽  
José Remohí ◽  
Marcos Meseguer

Abstract The introduction of time-lapse imaging to clinical in vitro fertilization practice enabled the undisturbed monitoring of embryos throughout the entire culture period. Initially, the main objective was to achieve a better embryo development. However, this technology also provided an insight into the novel concept of morphokinetics, parameters regarding embryo cell dynamics. The vast amount of data obtained defined the optimal ranges in the cell-cycle lengths at different stages of embryo development. This added valuable information to embryo assessment prior to transfer. Kinetic markers became part of embryo evaluation strategies with the potential to increase the chances of clinical success. However, none of them has been established as an international standard. The present work aims at describing new approaches into time-lapse: progress to date, challenges, and possible future directions.


Toxicology ◽  
1997 ◽  
Vol 116 (1-3) ◽  
pp. 123-131 ◽  
Author(s):  
Lynn A. Hanna ◽  
Jeffrey M. Peters ◽  
Lynn M. Wiley ◽  
Michael S. Clegg ◽  
Carl L. Keen

Sign in / Sign up

Export Citation Format

Share Document