Lower reference limit for semen characteristics (according to WHO Laboratory Manual for Examination and Processing of Human Semen, 5th edition) Parameters Lower reference limit Semen volume 1.5 ml Total sperm count (106/ejaculate) 39*106 Sperm concentration (106/ml) 15*106 Total viability (PR+NP, %) 40% Forward motility (PR, %) 32% Survival rate (live sperm, %) 58% Sperm morphology (normal morphology, %) 4% Other consensus thresholds pH ≥7.2 Peroxidase-positive leukocytes (106/ml) <1.0 MAR test (motile sperm bound to granules, %) <50 Immunobead test (motile sperm bound to immunobeads, %) <50 Seminal plasma zinc (μmol per ejaculate) ≥2.4 Seminal plasma fructose (μmol per ejaculate) ≥13 Seminal plasma neutral glucosidase (mU/one ejaculate) ≥20