Suresh C. Sikka, Ph.D., HCLD

Department of Urology, Tulane University School of Medicine, New Orleans, Louisiana, USA

Received 05/30/96; Accepted 07/02/96; On-line 08/01/96

The ultimate goal of a spermatozoan is the successful fertilization of ovum resulting in normal conception. In order to achieve this, the spermatozoa after spermiation must mature within the male genital tract, travel through the female reproductive system, undergo capacitation and acrosome reaction, bind to and penetrate the zona pellucidae of the ova as well as the oolemma, and finally fuse with the female pronucleus. Normal spermatozoa should properly undergo through all of these steps in order to fertilize the ova. However, many men who demonstrate normal parameters on standard semen analysis remain infertile (2). This suggests that the routine semen analysis (measurement of seminal volume, spermatozoal motility, density, viability and morphology) does not necessarily provide complete diagnostic information (3).

As a result of active research in the area of evaluation of human semen, a series of sperm function assays have been developed (Table I). However, no single test is capable of evaluating all of the steps involved in fertilization. At present only a combination of assays complementing each other can provide a comprehensive evaluation of sperm function (4). Although, ideal tests of sperm function will markedly improve the clinician's ability to diagnose male factor infertility and help in its management, evaluation of the potential causes of sperm damage leading to abnormal sperm function and infertility is an important area of investigation.