| -spermia, Further information: Testicular infertility factors |
| Aspermia—lack of semen; anejaculation |
| Asthenozoospermia—sperm motility below lower reference limit |
| Azoospermia—absence of sperm in the ejaculate |
| Hyperspermia—semen volume above upper reference limit |
| Hypospermia—semen volume below lower reference limit |
| Oligospermia—total sperm count below lower reference limit |
| Necrospermia—absence of living sperm in the ejaculate |
| Teratospermia—fraction of normally formed sperm below lower reference limit |
Asthenozoospermia (or asthenospermia) is the medical term for reduced sperm motility. Complete asthenozoospermia, that is, 100% immotile spermatozoa in the ejaculate, is reported at a frequency of 1 of 5000 men.[1] Causes of complete asthenozoospermia include metabolic deficiencies, ultrastructural abnormalities of the sperm flagellum (see Primary ciliary dyskinesia) and necrozoospermia.[1]
It decreases the sperm quality and is therefore one of the major causes of infertility or reduced fertility in men. A method to increase the chance of pregnancy is ICSI.[1] The percentage of viable spermatozoa in complete asthenozoospermia varies between 0 and 100%.[1]