Expansion
Volume, concentration, motility and morphology
Expansion
Approximate World Health Organization lower reference limits:
| Parameter | Lower limit |
|---|---|
| Volume | 1.5 ml |
| Concentration | 15 million per ml |
| Total count | 39 million |
| Progressive motility | 32 per cent |
| Total motility | 40 per cent |
| Normal morphology | 4 per cent |
| Vitality | 58 per cent |
Terminology: oligospermia (low count), asthenospermia (poor motility), teratospermia (abnormal forms), azoospermia (none).
Causes of impaired spermatogenesis
- Pre-testicular: hypogonadotrophic hypogonadism, hyperprolactinaemia, anabolic steroid use (which suppresses the axis)
- Testicular: varicocele, cryptorchidism, mumps orchitis, Klinefelter syndrome, chemotherapy, radiation, heat
- Post-testicular: obstruction, congenital absence of the vas (associated with cystic fibrosis), retrograde ejaculation
Sample collection matters: 2 to 7 days of abstinence, examined within an hour, and kept at body temperature.