Figure 1
From: Evaluation of day one embryo quality and IVF outcome – a comparison of two scoring systems
Simplified classification of pronuclear morphology originally published by Tesarik and Grecco [6]. Pattern "0": Zygotes exhibiting the same number of small nucleolar precursor bodies (NPB) evenly distributed in the nucleus or large NPB with polarized distribution between the two pronuclei. Pattern "other": All other non-symmetrical alignments of the NPBs including different numbers of NBPs.