Evaluation of the clinical efficacy of embryo cryopreservation.

To fully evaluate the advantages of a cryopreservation program a method needs to be established to express the additional patients pregnant from cryopreservation. The patient specific method considers cryopreservation as augmentation only among patients without a pregnancy from the fresh transfer, or from previously transferred frozen material from the same harvest. In an analysis of the pregnancy rate at the Jones Institute between January 1996 and December 1998 we found a fresh pregnancy rate of 40.8% in the good responders and 28.8% in poor responders. The patient specific pregnancy rate in the same cycles was 53.4% in good responders and 32.3% in poor responders. Good responders less than 35 years of age with ten or more mature eggs at retrieval had a fresh pregnancy rate of 40.2% and a patient specific pregnancy rate of 57.9%. It is exceedingly important for the physician and patient to understand and comprehend the potential in cryopreserved material.