The recent article by Karagenc et al. once again shows that atmospheric oxygen is
detrimental to embryo development in vitro. This study demonstrates that zygotes can readily
develop into blastocysts under ambient oxygen, but in spite of their morphologically normal
appearance, the viability of many of these embryos is compromised, with the most
pronounced effect on ICM development. Numerous other studies have reached the same
general conclusions, but in spite of the strong body of evidence derived from animal studies …