Comparison of three sperm-counting methods for the determination of sperm concentration in human semen and sperm suspensions

Abstract

Background: Sperm counts are currently being performed using a variety of methods that produce results that do not correlate well with each other or with the current "gold standard" reference method, hemacytometer. Significant differences in the accuracy of sperm counts using these different counting methods emphasize the need for standardization and quality control procedures to ensure adequate intermethod agreement between sperm counting methods. We compared sperm counts using 3 commonly used methods - hemacytomer, Cell-VU, and Makler - applied to both semen and sperm suspensions prepared from semen. Methods: Semen samples were obtained by masturbation from 60 outpatient volunteers. Sperm suspensions containing low, medium, and high sperm concentrations were prepared from 38 of these semen samples. The results of sperm counts on semen and sperm suspension samples were analyzed with SPSS 11.0 software. Results: Compared with the Cell-VU method, the hemacytometer and Makler methods overestimated sperm concentration in both semen and sperm suspension samples. Sperm counts in randomly selected semen samples (n = 35), and semen samples containing low, medium, or high sperm concentrations, were higher by hemacytometer than the Makler method, due, most likely, to the dilution of semen required when counting sperm concentration using a hemacytometer. Conclusion: The Cell-VU method of sperm counting provided the best accuracy and precision among the 3 methods we studied and may represent a better worldwide "gold standard" for sperm counts than the current hemacytometer method.