Obstructive and Nonobstructive Azoospermia: A Review of Clinical and Diagnostic Differences

Abstract

Azoospermia is one of the main causes of male infertility, characterized by the complete absence of spermatozoa in the ejaculate. It can be classified into two types: obstructive, when spermatogenesis is preserved but a blockage occurs in the reproductive tract; and non-obstructive, when sperm production fails, usually due to genetic, endocrine, or toxic factors. Obstructive azoospermia accounts for about 40% of cases and is associated with conditions such as congenital bilateral absence of the vas deferens, vasectomy, and infections, while non-obstructive azoospermia corresponds to 60%, mainly related to Y-chromosome microdeletions, Klinefelter syndrome, and exposure to harmful agents. The differential diagnosis between both conditions is essential for therapeutic planning, which may include surgical procedures such as PESA, MESA, TESA, TESE, and micro-TESE, as well as assisted reproduction techniques, particularly intracytoplasmic sperm injection (ICSI). This study presents a literature review on the clinical, etiological, and therapeutic differences between the two types of azoospermia, highlighting the importance of genetic counseling and sperm retrieval strategies in the management of male infertility