Sperm motility refers to the sperm’s ability to move in a straight line. If the movement of the sperm is sluggish or not in a straight line, then the sperm will have a hard time attempting to invade the cervical mucus, or penetrate the egg.
Healthy, normal shaped, quick swimming sperm are pertinent in not only fertilizing an egg, but also in providing optimal DNA so that the embryo is genetically healthy and has a greater chance of surviving.