The fact that only about one-third of single-cell embryos form blastocysts reflects the one-third success rate of IVF that is found clinically. By playing the film backward, and using software to measure various parameters, the Stanford group identified just three factors that were predictive of future blastocyst formation: the duration of time that it takes the first cell to divide for the first time; the time between that first division and the second; and the synchronicity of the second and third mitosis.
