Novel markers of male infertility.

Diagnostic tests should detect disease, have prognostic value, and aid in clinical decision making. Nowhere else in laboratory medicine does one have to interpret a subject's results within the dynamic of a couple as in reproductive medicine. Abnormal markers of male reproduction do not necessarily mean sterility, but instead indicate problems with spermatogenesis, sperm maturation, transport through epididymis and ejaculatory duct, or abnormal ejaculatory function. Decades of research suggest that one test will never fit all scenarios and a battery of assays evaluating different aspects of male reproduction will likely have the best prognostic value. There is a strong need for standardization and harmonization of evolving assays to establish their clinical relevance. Next-generation genome sequencing and the discovery of small noncoding RNAs in sperm already are changing the field and permit further insight into the biology of male reproduction as well as offer new diagnostic tests.