This study investigated whether one of the two viability tests is superior to the other in cases with asthenozoospermia (reduced sperm motility) in which the rate of immotile spermatozoa exceeded 50%. A total of 21 male patients who visited the IVF (In Vitro Fertilization) Unit of the Department of Obstetrics and Gynecology at the Faculty of Medicine of Dokuz Eylul University were included in the study. Semen samples were subjected to both macroscopic and microscopic examinations. Makler counting chamber was used for the sperm motility and concentration analyses. All semen samples were subjected to eosin viability test and HOS (hypo-osmolar swelling test) test. The result of the eosin test was accepted as normal in the case of presence of 75% or more unstainable spermatozoa in a semen sample. The result of the HOS test was accepted as normal if swelling behavior were observed in more than 60% of the spermatozoa tails in a semen sample. Both tests yielded normal results in 10 cases, while the test results were found to be abnormal in 4 of the cases. In 7 cases, the HOS test yielded abnormal results, while the results of the eosin test were found to be normal. The binomial (sign test) statistical evaluation revealed that the two tests have no superiority over one another(p>0,05). The fact that the HOS test as a viability test yielded very similar results when compared to the eosin test demonstrates the significance of the HOS test in the sense that it is economic.

Keywords: asthenozoospermia, eosin test, HOS test, sperm motility