RESUMO
<p><b>OBJECTIVE</b>One of the important reasons for male infertility is asthenozoospermia, for which there is no specific cure for the time being. The authors explored the clinical effect of L-carnitine for infertile males with asthenozoospermia.</p><p><b>METHODS</b>A total of 135 patients with asthenozoospermia were randomly divided into Groups A (n = 68) and B (n = 67), the former treated with L-carnitine (2 g/d) and vitamin E, while the latter with vitamin E only, both for 3 months. All the patients received semen analyses before and after the treatment, and were observed for adverse effects. The pregnancy rates of their wives were recorded.</p><p><b>RESULTS</b>Group A showed a significantly increased percentage of forward motile sperm after the treatment (45.4% +/- 11.1%) as compared with pretreatment (28.6% +/- 9.2%) (P < 0.01), but no statistically significant differences were found in sperm density and the percentage of the sperm of normal morphology (P > 0.05). The rate of pregnancy was significantly higher in Group A (31.1%) than in B (3.8%) after the treatment (P < 0.01). No adverse events were found during the treatment.</p><p><b>CONCLUSION</b>L-carnitine, capable of significantly improving sperm motility and raising the rate of pregnancy, is a safe and effective therapeutic option for asthenozoospermia.</p>