What is the most relevant standard of success in assisted reproduction? Is there a single 'parameter of excellence'?

An optimal standard of success reflects all risk and safety aspects of the treatment-related procedures. In this debate, we question whether one single standard of success can cover the complexity of assisted reproduction technology (ART). To emphasize the use of different parameters as standards of success, we calculated data from all IVF and ICSI cycles initiated at the Fertility Clinic, Rigshospitalet, Copenhagen, Denmark between 1999 and 2001. Several already established parameters were computed and, additionally, new suggestions for end-points were calculated. Three parameters were proposed as the best standards of success in ART: (i) number of oocytes per aspiration (8.7); (ii) number of ongoing implantations per embryo transferred (20%); and (iii) number of deliveries per embryo transferred (14%). These parameters cover aspects of all steps in ART, i.e. the stimulation, laboratory and embryo transfer/outcome phase, also termed the pre-in vitro, in vitro and post-in vitro phase. We suggest that the final description of an ART programme should be a balanced choice of the three standards of success proposed herein. If these standards are implemented as national gold standards, the future goal of homogeneous reporting of success rates in ART is within reach.