Received June 30, 2015
Accepted August 01, 2015

Dear Editor-in-Chief: The Editorial of this year’s second issue of your interesting journal commented on the increasing use of time-lapse (TL) image systems in laboratories of assisted reproduction (Franco Jr, 2015). It was concluded that possible advantages of TL systems over classical morphological analyses are still lacking clear evidence. Moreover, new parameters assessing the pronuclear stage obviously have been introduced quite recently whereas the classical TL parameters mostly focused on the kinetics of embryo development (Franco Jr, 2015). Particularly with respect to deviations from the normal number of pronuclei (PN) I should like to add some thoughts.