無精症

阻塞性無精症
副睪近輸精管處精蟲較成熟&數量較多
精蟲濃度可達100萬/ml

非阻塞性無精症
精蟲活動力較低&常不動
需幾小時培養後活動力較為提高
http://www.maleinfertility.org/new-retrieval4.html

Sperm quality in obstructive and non-obstructive azoospermia

In the normal male reproductive tract, sperm exiting the testis have minimal motility and limited egg fertilizing capacity. Sperm acquire the potential for improved motility and fertilizing ability during epididymal transit. So, in the unobstructed epididymis, sperm of optimal quality (as evaluated by percent motile cells) are found in the most distal epididymis.

1. Obstructive Azoospermia: The obstructed epididymis or congenital absence of the vas deferens shows the opposite pattern of sperm quality: optimal sperm quality in the proximal epididymis and very poor quality in the most distal segments. This finding of "inverted motility" is expected in the obstructed male reproductive tract since sperm production that continues in the testis and reabsorption of those sperm is an active process in the most distal regions of the system. The most distal obstructed epididymis tends to contain dilated yellow tubules that are packed with macrophages reabsorbing old, degenerated sperm.⁹ Therefore, sperm retrieval should be performed from the proximal obstructed epididymis and testis, and higher quantities of motile spermatozoa can be obtained. In fact, motile spermatozoa are found at concentrations up to 1 million sperm per microliter in the fluid of obstructed epididymis.

2. Non-obstructive Azoospermia: A common observation for testicular sperm samples is that retrieved spermatozoa are immobile or have a sluggish twitching motion. In this situation, some sperm production is focally present within the testis, despite the fact that inadequate numbers of sperm are released from the testis to make it into the ejaculate. After several hours of incubation in vitro, testicular sperm typically show some motility. The lack of initial motility does not necessarily reflect a lack of viability for testicular sperm, since these sperm have never acquired motility. Non-motile ejaculated sperm have acquired and lost motility, as sperm viability is lost, rendering the sperm useless for ICSI.

Typical criteria for poor sperm production, including an elevated serum FSH level or decreased testicular volume, does not predict which patients have sperm found with testicular sperm extraction (TESE). Even the histologic patterns on diagnostic testicular biopsy (Sertoli cell-only, maturation arrest, hypospermatogenesis) cannot perfectly predict the chance of finding sperm with TESE. However, many centers require diagnostic biopsies prior to TESE procedures to rule out carcinoma-in-situ (intratubular germ cell neoplasia) that is present in up to 3% of men with NOA who are candidates for treatment with TESE-ICSI.⁸