Asthenopermia, or asthenozoospermia, is the term used when the percentage of mobile sperm is lower than average. Complete asthenozoospermia, meaning that all sperm cells in a sample are not moving, occurs in about 1 in 5000 men.
Asthenozoospermia results in infertility, as the sperm are unable to swim and reach the egg. This can be overcome using IVF-ICSI techniques.