When a couple is unable to conceive a child after at least a year of trying, approximately 40 percent of the time the problem is associated with male infertility. Causes of male infertility can range from impaired sperm production to a testosterone deficiency, a congenital defect or disease process, testicular trauma, prostatitis or another type of infection, and even certain medications. Sperm production may also be impacted by an underlying medical condition such as a spinal cord injury. Urologists who specialize in male fertility can provide advanced diagnostic tests and treatments to help couples who are confronting male infertility. Treatment usually starts with medications but can also involve surgical interventions such as microsurgical vasovasostomy (vasectomy reversal), transurethral resection of the ejaculatory duct (TURED), hormone replacement therapy and assisted reproductive techniques such as in vitro fertilization.