Morphokinetics of embryos—where are we now?

Conventional embryo selection by morphological evaluation is still related to relatively low implantation and live birth rates. To resolutely take up this challenge, noninvasive and invasive methods of embryo selection are still debated regarding their improvement on in vitro fertilization (IVF) success rates. Within the past few years, combining morphology with kinetics has inspired a new field named “morphokinetics,” which enabled a new way of evaluating and selecting embryos by continuous surveillance. Many studies have tried to connect more or less conclusively embryo development, timing of the mitotic divisions, embryo viability, and implantation. The aim of this review is to summarize the current understanding of time-lapse monitoring in the IVF laboratory and to discuss the evidence regarding morphokinetics as a predictive method for blastocyst formation, aneuploidy detection, and implantation potential.