Jacques Cohen, et. al. RBM Online (2012) 25, 585
There is high variability from country to country and clinic to clinic. The number of variables encountered throughout the complete Artificial Reproductive Technology (A.R.T.) process is tremendous as each individual A.R.T. process has its own set of variables. Everything from technique to equipment to procedures to laboratory environment to staff training needs to be considered. The amount of variability increases exponentially with the number of processes.
Listen to Dr. Robert Woolcott's keynote address at the GFA reception at ESHRE to learn more.