Up to now, morphological assessment of embryos is still the main method to screen embryos with the most potential for implantation in in vitro fertilization (IVF) laboratories. However, due to the lack of a unified consensus and quantitative indicators, the subjective differences among laboratories limit the comparison of inter-laboratory quality among reproductive medicine centers, and it restricts the in-depth analysis and wide application of massive embryo data nationwide. In order to refine the quality system of IVF laboratories and improve the service of assisted reproductive technology, this consensus is initiated by the Chinese Association of Reproductive Medicine, and co-edited with other reproductive medicine centers.

Reproductive techniques, assisted; Cleavage-stage embryos; Blastocyst; Morphological assessment; Consensus