Asthenozoospermia

Asthenozoospermia is the medical term for a large percentage of sperm that do not swim straight forward quickly. A reduction in motility (movement) decreases the likelihood of sperm successfully swimming up the female reproductive tract in order to fertilize an egg.

According to the World Health Organization (WHO), asthenozoospermia occurs with less than 40% total motility (any movement in a semen sample) or 32% progressive motility (forward movement in a straight direction.)

An analysis of sperm motility during a semen analysis can provide insight into how sperm move, including their direction, speed, and endurance.

Asthenozoospermia may also be known as asthenospermia.