This test is performed to evaluate sperm quantity and quality. It is one of the principal tests required in the diagnostic evaluation of infertility. Men who have previously fathered children still need a semen analysis as sperm quantity and quality may have diminished over time. The semen analysis evaluates a variety of semen parameters including the concentration (count), motility (percentage of sperm moving) and morphology (percentage of normally-shaped sperm) in the ejaculate. Abnormalities in one or more of these parameters might compromise the ability of the sperm to fertilize the eggs. If a semen analysis is abnormal, a repeat semen analysis is warranted and in some cases we recommend that the man see a urologist for an evaluation including a history, physical examination and possible laboratory testing.