WHO laboratory manual for the Examination and processing of human semen FIFTH EDITION 2010

WHO laboratory manual for the Examination and processing of human semen    FIFTH EDITION 2010

224 APPENDIX 1   Reference values and semen nomenclature

Comment 5: Men whose semen characteristics fall below the lower limits given here are not necessarily infertile; their semen characteristics are below the reference range for recent fathers—as are, by definition, those of 5% of the fertile men who provided data used in the calculation of the reference range. 

Comment 6: A man’s semen characteristics need to be interpreted in conjunction with clinical information.

Comment 7: There may be regional differences in semen quality, or differences between laboratories; laboratories should consider preparing their own reference ranges, using the techniques described in this manual.

Comment 8: Time to pregnancy is also affected by the female partner’s fertility status.

Table A1.1 Lower reference limits (5th centiles and their 95% confidence intervals) for semen characteristics 

Parameter Lower reference limitSemen volume (ml) 1.5 (1.4–1.7)

Total sperm number (106 per ejaculate) 39 (33–46)

Sperm concentration (106 per ml) 15 (12–16)

Total motility (PR + NP, %) 40 (38–42)

Progressive motility (PR, %) 32 (31–34)

Vitality (live spermatozoa, %) 58 (55–63)

Sperm morphology (normal forms, %) 4 (3.0–4.0)

Other consensus threshold values

pH !7.2

Peroxidase-positive leukocytes (106 per ml) "

1.0MAR test (motile spermatozoa with bound particles, %) 

"50Immunobead test (motile spermatozoa with bound beads, %) 

"50Seminal zinc (#mol/ejaculate) 

!2.4Seminal fructose (#mol/ejaculate)  

!13Seminal neutral glucosidase (mU/ejaculate) !20