Morphological classification of human in-vitro fertilization embryos based on the regularity of the asynchronous division process.

A previous study detailed the morphometric characteristics of living in-vitro fertilized human pronuclear zygotes and cleaved embryos. A comparison of the different embryo cell stages confirmed the asynchronous division process during early embryo development. Global results showed no evidence of morphometrical differences between embryo subpopulations according to their classical microscopical grading. In this report, further information on illumination of human embryos and analysis of image processing is given. Some examples of embryo images belonging to a normal asynchronous division process are shown. A new parameter was retrospectively attributed to each cleaved embryo based on whether or not they were considered to have undergone asynchronous division that qualified as normal. A non-parametric analysis of this preliminary sample showed that this qualifier was correlated with implantation and acted complementarily with embryo grading. In conclusion, the asynchronous division process qualified as normal and its deviations seem to be a new parameter to take into account during embryo scoring.