Testicular biopsy is an additional test for the study of male fertility. It is a surgical procedure in which a fragment of the testicle is removed in order to look for spermatozoa that can later be used to perform an ICSI.
This test is also useful in cases of absence of sperm in the ejaculate, which is known as azoospermia. The main reason for this is that testicular biopsy will help distinguish between a problem of sperm production or a blockage in the passage of sperm, i.e. the diagnosis of secretory azoospermia and obstructive azoospermia respectively can be established.