Clinical use and misuse of automated semen analysis.
Abstract
During the past six years, there has been an explosion of technology which allows automated machine-vision for sperm analysis. CASA clearly provides an opportunity for objective, systematic assessment of sperm motion. But there are many caveats in using this type of equipment. CASA requires a disciplined and standardized approach to semen collection, specimen preparation, machine settings, calibration and avoidance of sampling bias. Potential sources of error can be minimized. Unfortunately, the rapid commercialization of this technology preceded detailed statistical analysis of such data to allow equally rapid comparisons of data between different CASA machines and among different laboratories. Thus, it is now imperative that we standardize use of this technology and obtain more detailed biological insights into sperm motion parameters in semen and after capacitation before we empirically employ CASA for studies of fertility prediction. In the basic science arena, CASA technology will likely evolve to provide new algorithms for accurate sperm motion analysis and give us an opportunity to address the biophysics of sperm movement. In the clinical arena, CASA instruments provide the opportunity to share and compare sperm motion data among laboratories by virtue of its objectivity, assuming standardized conditions of utilization. Identification of men with specific sperm motion disorders is certain, but the biological relevance of motility dysfunction to actual fertilization remains uncertain and surely the subject for further study.