World Health Organization reference values: Semen volume: 1.5 ml or more pH: 7.2-7.8 Sperm concentration: 15 million spermatozoa per ml or more Total sperm number: 39 million spermatozoa per ejaculate or more ( Range 36-42 million /ml) Total motility : 40% or more motile or 32% or more with progressive motility Round cells: <5 million /mL Vitality: 58% or more live spermatozoa Sperm morphology (Strict criteria ): 4% or more of normal forms Sperm Agglutination:<2