There are several characteristics that, when examined in sperm testing, can indicate the health of sperm and overall male fertility.
Sperm count and concentration
Sperm count is the total number of sperm in a particular quantity of semen, the fluid that carries sperm out of the penis. Sperm concentration refers to how densely packed those sperm are within the semen. For example, a sample may include 3 milliliters of semen (volume) and a total sperm count of 45 million; that would be a concentration of 15 million sperm per mL.
Sperm motility
Motility refers to the ability of the sperm to move or “swim,” which is essential for them to move through the female reproductive system and fertilize the egg. Progressive motility is the best type of movement that can be seen in sperm testing—that means the sperm move forward in straight lines or in large circles, as opposed to in small tight circles or along erratic paths.
Sperm morphology
Morphology means the sperm’s structure or shape, which is ideally a smooth oval head, a well-defined acrosome, or cap, that covers 40–70% of the head, and a long tail with no visible abnormalities. This shape is important because it impacts a sperm’s ability to travel to and penetrate an egg.
Learn more in our guide to sperm testing.