When resorting to egg donation, the chances of achieving pregnancy are practically identical whether fresh or frozen (vitrified) eggs are used.
The reality is that, once the sperm is introduced into the egg by microinjection, the subsequent biological development does not distinguish between one method or the other.
The only important factor to consider is the number of eggs with which the treatment begins. When working with vitrified eggs, they must undergo a preliminary thawing phase, and it is possible that some will not survive this step. If the number of viable eggs at the outset is reduced, we could logically obtain fewer embryos, which could affect the cumulative chances of pregnancy.
For this reason, the technology and experience of the assisted reproduction laboratory play a crucial role. Although in the early days of this technique it was common to lose oocytes during the thermal process, current advances have radically changed the landscape, achieving extremely high survival rates.
