Two letters to the editor were published on Human Reproduction, Volume 35, Issue 11, November 2020. They have different opinions about if the cryostorage duration affects the clinical outcome of vitrified embryos. The opinions from both sides are very interesting.
1. Lodovico Parmegiani, et al, “The effect of cryostorage duration on vitrified embryos: has vitrification suddenly become unsafe?”, Human Reproduction, Volume 35, Issue 11, November 2020, Pages 2632–2633.
2. Jianghui L, et al, “Reply: We urge caution: a causal relationship between vitrification and declined clinical success cannot be inferred”. Human Reproduction, Volume 35, Issue 11, November 2020, Pages 2633–2635.
