[Semen analysis in involuntary childlessness. What information does it provide?]

Involuntary childlessness is a common problem. In about 50% of cases, inadequate semen quality plays a relevant role. A semen analysis provides information regarding exocrine function of the male reproductive organs of the testes, epidydimis, seminal vesicles, prostate gland, and vas deferens. These parameters can only be interpreted in conjunction with medical history and physical examination. Then they can be useful to identify relevant disorders or the causes of these disturbances. The fundamental principles for the interpretation of a semen analysis are easily learned and traditionally belong to the field of dermatology. This article explains the variables which are examined in a routine semen analysis as well as the reference values. Furthermore, common causes for deviations from the normal values are discussed to allow decision-making for further diagnostic workup. The interpretation of these values must always take into account the situation of the couple.