Demonstration of the site of obstruction in azoospermia by biochemical markers.

This study was carried out on 25 patients with azoospermia and normal serum FSH levels signifying obstruction as its cause. To determine the site of obstruction semen transferrin levels, carnitine and fructose were estimated. Patients with an obstruction at the testis-epididymal junction had low levels of transferrin but normal levels of carnitine and fructose. Patients who had lower levels of transferrin and carnitine, but normal levels of fructose had obstruction at the epididymal level, probably in the tail of the epididymis. Obstruction of the ejaculatory ducts was signified by lower levels of all parameters in the semen. Our study showed that levels of transferrin, carnitine and fructose when used in conjunction with each other could localize the site of obstruction in azoospermia.