Purpose: Pentoxifylline (PF) has been used to enhance sperm motility in many in vitro fertilization programs. The twofold purpose of this study was to determine whether PF stimulates fresh or frozen epididymal and testicular totally immotile spermatozoa and whether it can be used to select viable spermatozoa for intracytoplasmic sperm injection (ICSI).
Methods: To test the effect of PF on motility, 10 samples of totally immotile spermatozoa were incubated for 10 min with 3.6 mM PF. Motility was initiated in all cases (14.8% mean motility after PF treatment of five samples of fresh or frozen epididymal spermatozoa and 13.6% mean motility of five samples of fresh or frozen testicular spermatozoa). To assess PF for selection of viable spermatozoa before ICSI, we compared the outcome of ICSI in 20 cycles using fresh or frozen epididymal or testicular PF-treated immotile spermatozoa and 139 control ICSI using fresh or frozen epididymal or testicular spontaneously motile spermatozoa.
Results: Fertilization rates were similar in the PF and control groups (45.2% vs. 51.0%). Embryo quality and division stages at the time of transfer were comparable. Six pregnancies occurred in PF-ICSI group (30.0% per cycle vs. 26.6% in control group) including two deliveries of healthy children and four ongoing pregnancies.