One of the issues that is generating much controversy amongst oocyte donation patients concerns the origin of the eggs. That is, whether or not they have been frozen and which of these two alternatives is best.
Use of cellular vitrification over the last few years has led to huge progress in terms of survival rates for spermatozoa, oocytes and embryos after freezing. Indeed, the clinical results for frozen oocytes are similar to those for fresh oocytes when rigorous freezing and defrosting techniques are used.
The popularity of previously frozen oocytes (vitrification) is based mainly on the fact that it affords both the team of doctors and the patient greater flexibility.