Normal seminal plasma could preserve human spermatozoa against cryopreservation damages in Oligozoospermic patients

Background Cryopreservation of human spermatozoa has been identified as an efficient procedure to preserve fertility in men before any cancer therapy or surgical infertility treatment. Despite the benefits of the procedure, the deleterious effects of cryopreservation have been proven on sperm structure and function. This study aimed to evaluate seminal plasma effects on human sperm characteristics after cryopreservation, and compare the addition of normozoospermic and oligozoospermic seminal plasma in the prepared oligozoospermic samples. Semen samples were collected from fifty-five oligozoospermic men and the twenty fertile individuals who referred to the infertility center. At first, a semen analysis was carried out on each neat ejaculate, and then some were cryopreserved. The remainder of the semen was divided into two, one for seminal plasma removal and the other for sperm preparation. Then, the prepared spermatozoa were cryopreserved in three groups: one with, and another without the addition of oligozoospermic seminal plasma, and still another with the addition of normal seminal plasma. After thawing, sperm DNA integrity, viability, motility, and morphology were determined. Results The percentages of all parameters were significantly lower after cryopreservation in all groups compared to the fresh sample. However, this reduction was lower in the oligozoospermic samples cryopreserved with normal seminal plasma. Conclusion The results indicated that seminal plasma in oligozoospermic patients could not support sperm against cryo-injuries, an indication likely due to insufficient antioxidants and other protective components in oligozoospermic patients. However, normal seminal plasma could slightly preserve sperm characteristics after cryopreservation in oligozoospermic patients.