CRYOPRESERVATION - THE PROBLEM OF EVALUATION

A simple evaluatory formula for reporting pregnancy rates involving cr yopreserved material has so far remained elusive, It is highly desirab le to have a method which would allow not only an evaluation of cryote chnology per se, but also an evaluation of the role of cryotechnology in enhancing the total reproductive potential of a single cycle, In th is paper, nine separate formulae are described which can be used for t he evaluation of cryopreservation, It is concluded that none of the ex isting formulae used alone expresses the total potential of cryopreser vation, and that while each formula provides information regarding som e aspect of the role of cryopreservation, the most comprehensive evalu ation requires the answer to five different equations. The other four formulae, while often used, are regarded as providing information whic h is unsubstantiated or does not allow complete evaluation.