“…Same beneficial effects of the co‐culture have been obtained with embryos cultured in groups rather than alone (Spindler & Wildt, ). It is likely that the secretion and the sharing of beneficial paracrine factors and embryotrophic compounds modulate the nutrient profile and protect cell against culture‐induced stress, ROS and toxins (Buccione, Vanderhyden, Caron, & Eppig, ; Conway‐Myers, ; Plachot, ; Vanderhyden, Caron, Buccione, & Eppig, ; Wiemer, Cohen, Tucker, & Godke, ). In general, the presence of denuded oocytes in co‐culture positively influence the cumulus cells activities of mammalian COCs due to an active exchange of oocyte‐secreted factors (OSFs) that regulate the oocyte metabolism, proliferation, cumulus expansion and differentiation (Gilchrist, Lane, & Thompson, ; Hussein, Thompson, & Gilchrist, ).…”