Table 3.

Main alterations detected in prior studies of blastocysts cultured under physiologic (5%) and atmospheric (20%) O₂ concentration, compared to in vivo blastocysts. The relative increase is based assuming 100% in vivo blastocysts.

	5% O2 Concentration	20% O2 Concentration	References
Mitochondrial numerical density	~100–200 less mitochondria/area detected.	~300 less mitochondria/area detected.	Belli et al., 2019 [5]
Vacuolization	No differences.	Nearly 200 more vacuoles/area detected.	Belli et al., 2019 [5]
mtDNA copy number	~107 less copied detected.	~1.5 (107) less copies detected.	Belli et al., 2019 [5]
Alteration of the global gene expression	The expression of 264 genes is altered compared to in vivo control.	The expression of 2133 genes is altered compared to in vivo control	Feuer et al., 2017 [37]
Cell number	25 more blastomeres than in vivo control.	10 less blastomeres than in vivo control.	Rinaudo et al., 2006 [31]