Oocytes cryopreservation: state of art.

In the present review article we sought to analyze, on the basis of a systematic review, the indications, rationale of oocytes cryopreservation, as well as the techniques that improved the aforementioned procedure in order to higher the pregnancy rate in women undergoing that procedure. Moreover, we pointed out the importance of oocytes cryopreservation in the research field as oocyte banking may be of utmost importance to increase the availability of oocytes for research applications such as genetic engineering or embryo cloning. Oocyte freezing has 25 year of history alternating successes and setbacks. Human oocytes have a delicate architecture but are freezable. Clinical efficiency remains low, but healthy children have been born, indicating that chromosomally normal embryos can originate from frozen oocytes. Freezing protocols are not yet optimal and it is now desirable to combine empirical and theoretical knowledge.