Diagnostic applications for inhibin and activins

► Diagnostic value of inhibin and activin measurements were evaluated. ► Inhibin A enhances diagnosis of Down syndrome in second trimester pregnancy. ► Total inhibin is a marker of certain forms of ovarian cancer. ► Inhibin B is useful in male infertility. ► Other applications remain unclear. Inhibin and activins play major roles as paracrine and autocrine signaling molecules in reproduction and development where the main emphasis has been placed in developing potential diagnostic applications. While a role for activin assays in diagnostics has so far been unfounded, ELISAs specific for the biologically active inhibin A and B dimers, and for free inhibin alpha subunits, alone or in combination have found some specific diagnostic applications. Addition of inhibin A to the triple test for Down syndrome in the second trimester of pregnancy, measurement of total inhibin as a marker of certain forms of ovarian cancer in specific circumstances, and inhibin B for male fertility are useful diagnostics. A review of the evidence so far suggests that other applications for inhibin and activin assays have yet to be confirmed, or translated into reliable tools for clinical practice.