ABSTRACT
Azoospermia as defined by a complete absence of sperm in the ejaculate after centrifugation of two different semen specimens can affect about 1%–2% of males and 10%–15% of infertile males. Obstructive azoospermia (OA) is the absence of spermatozoa in the ejaculate secondary to a transport failure between the testis and urethra. It may be caused by a congenital or acquired blockage anywhere along the male genital tract, the epididymis, the vas deferens, or the ejaculatory duct. Congenital OA can be a result of congenital bilateral absence of vas deferens usually accompanied by mutations of the cystic fibrosis transmembrane regulator protein, that would result in absent vasa and partial or complete absence of the epididymis. A semen analysis should be performed at least 3 times over a 6-month period with a 48-hour period of abstinence. A centrifuged semen sample must be analyzed to diagnose azoospermia.
