Computerized semen analysis: objective measurement of semen characteristics is biased by subjective parameter setting

To test the influence of parameter settings on results of automated semen analysis, microscopic images of 43 semen samples were videotaped. Tapes were analyzed by the CellSoft system (CRYO Resources Ltd., New York, NY) at 12 different parameter combinations for gray scale, number of frames analyzed, and minimum number of frames analyzed for velocity measurements. The data indicate that values obtained for concentration, percentage of motile sperm, velocity, and linearity depend, to varying degrees, on the settings of the computer. It is concluded that results of automated semen analysis may not be comparable among different laboratories unless identical parameter settings are used. The need for general agreement of these details among different users is stressed.