Is morphokinetic analysis the answer?

Efforts aimed at improving pregnancy rates have focused on the search for additional markers of viability to supplement current criteria for embryo selection. Time-lapse technology represents a powerful tool in assisted reproduction for evaluating embryos dynamically. Whilst standard methods of embryo assessment are based on subjective morphology evaluation at discrete time points, thereby limiting the information produced for embryo selection, time-lapse recording introduces several additional morphokinetic parameters for embryo evaluation. This additional information can improve implantation rates and reproductive outcomes. This review surveys available knowledge on time-lapse imaging to provide an overview of the advantages and applications of this technology.Standard methods of embryo assessment in an IVF laboratory are based on subjective morphology evaluation. These evaluations are done at discrete time points because of the negative effects that manipulation has on embryo development, limiting the information for selecting the best embryos. The efforts aimed at improving pregnancy rates have focused on the search of additional markers of viability, new ways of evaluating embryos with more information to supplement current criteria for embryo selection. Time-lapse technology represents a powerful tool in assisted reproduction. It is based on especially designed instruments which take images of the embryos every 15–20 min automatically, without taking the embryos outside the incubator to minimize manipulation. This also provides additional information to the embryologist, being able to evaluate embryos from a dynamic point of view by studying exact timings of some important parameters of embryo development. The aim of this new selection method is to improve implantation and pregnancy rates by having extra information to select embryos with higher implantation potential. This objective and reliable data should also be useful to reduce multiple pregnancies, because of the possible complications involved, transferring only one embryo. This review details what is known about time-lapse imaging, providing an overview of the advantages and applications of this technology as well as going through some of the most relevant studies published in this field.