Received April 18, 2020
Accepted October 20, 2020

Objetive: Investigate the possible effect of an acute sildenafil dose in astenozoospermic patients. Methods: An experimental, descriptive, prospective and non-blinded study was performed in 32 patients that were diagnosed asthenozoospermic according to the WHO criteria after two consecutive semen analyses (samples 1 and 2) and were asked to provide a new semen sample two weeks after the initial exams (sample 3). One hour prior to the semen collection, patients were treated orally with 100 mg of sildenafil. Samples 2 and 3 were allowed to liquefy and density gradients were performed. Sperm motility was assessed by Computer-assisted sperm analysis (CASA). Results: No significant differences were observed when samples obtained before (sample2) or after sildenafil administration (sample3) were compared. However, a single oral 100 mg sildenafil dose in asthenozoospermic patients increase the percentage of motile sperm recovered after density gradient centrifugation. Conclusions: An acute administration of sildenafil increases mobile sperm recovery after density gradient centrifugation in asthenozoospermic males and may produce more available motile sperm to perform intra uterine insemination or to improve the chances of success in this procedure. This approach may be used as an alternative strategy in assisted reproductive programs. Sildenafil was well tolerated and no patient was withdrawn from the study due to adverse events attributed to sildenafil.