Morphokinetic features of the bovine embryo may be associated with lethal chondrodysplasia condition

This case report details the identification of lethal chondro­dysplasia (LCD) in a Holstein embryo following embryo trans­fer and initial normal development during pregnancy. Lethal chondrodysplasia is a genetic disorder characterized by se­vere skeletal deformities during the developing pregnancy, leading to detrimental live-calf outcomes and cow-calf wel­fare. In this study, an in vitro produced (IVP) Holstein embryo was classified stage 7, quality grade 2, by an experienced bo­vine embryologist and was transferred to a recipient Holstein heifer. A video of this embryo was recorded with a View 4k camera attached to a Nikon SMZ 1270 microscope before load­ing and transferring. The recipient showed normal pregnancy progression, but resulted in abortion near ~180 days post em­bryo transfer. Post-abortion examination revealed severe skel­etal deformities consistent with LCD. Upon analysis, embryo morphokinetics which evaluates developmental patterns and cellular activity from the embryo video showed normal activ­ity levels, but higher variability and standard deviation in the LCD-affected embryo. This case underscores the limitations of initial embryo evaluations and highlights the potential of advanced embryo analysis technologies, such as computer vi­sion morphokinetic assessment, to detect genetic abnormali­ties earlier and improve breeding programs’ accuracy.