Azoospermia: incidence, and biochemical evaluation of seminal plasma by the differential pH method.

BACKGROUND Recent artificial reproductive technologies (ART) have enabled even azoospermic subjects to take part in "in vitro fertilization" programs. The aim of the present study was: a) to evaluate the incidence of azoospermic male partners of infertile couples; b) to determine whether biochemical evaluation of such azoospermic males can help to discriminate between obstructive and secretory azoospermia. METHODS Semen samples (n. 28,339; period 1990-1997) were analyzed according to WHO guidelines. In addition, in 108 azoospermic subjects, fructose, citric acid and L-carnitine (taken respectively as markers of seminal vesicle, prostate and epididymal function) were assayed using a new, faster technique, the differential pH method. RESULTS The incidence of azoospermic semen samples was 4.76%. The biochemical analyses were indicative diagnostically, especially with regard to obstructive azoospermia. However, in secretory azoospermia, biochemical analysis of seminal plasma did not offer particularly helpful indications, except in cases of hypogonadism. CONCLUSIONS Azoospermia accounts for a relatively high number of cases and justifies detailed attention to the diagnostic and therapeutic approach. Biochemical analysis of the seminal markers is a valid support for differential diagnosis between secretory obstructive azoospermia. It can therefore help in the correct recruitment of such patients for ART programs.