睪丸精子萃取術 (TESE)取得sperm TUNEL陽性率較低

對於射精精液中TUNEL 陽性細胞數量增多且輔助生殖技術失敗的男性，可以考慮進行TESE

TUNEL陽性精子是指DNA發生斷裂的精子，可透過TUNEL檢測（末端脫氧核苷酸轉移酶dUTP缺口末端標記法）進行檢測，顯示精子DNA受損，會對生育能力產生負面影響。

在顯微鏡下，TUNEL陽性精子通常呈現明亮的綠色螢光，其比例越高，輔助生殖的懷孕結局越差。

此檢測方法透過標記遊離的3'-OH末端來識別單鍊和雙鏈斷裂，從而區分受損（陽性）精子和完整（陰性）精子，並有助於評估男性不孕症。

TUNEL-positive sperm are spermatozoa with fragmented DNA, detected using the TUNEL assay (Terminal deoxynucleotidyl transferase dUTP nick end labeling), indicating DNA damage that negatively impacts fertility, often appearing as bright green fluorescence under a microscope, with high percentages correlating to poorer pregnancy outcomes in assisted reproduction. This assay identifies single and double-strand breaks by labeling free 3'-OH ends, distinguishing damaged (positive) sperm from intact (negative) sperm, and helps assess male infertility.  

Fertil Steril. 2015 Dec;104(6):1382-7.　

Higher pregnancy rates using testicular sperm in men with severe oligospermia

Objective: To evaluate assisted reproductive technology (ART) outcomes using testicular sperm in oligospermic men who previously failed to achieve paternity using TUNEL-positive ejaculated sperm.

Patient(s): Twenty-four oligospermic men who failed one or more ART cycles using ejaculated sperm with TUNEL-positive proportion >7%, and subsequently underwent microsurgical testicular sperm extraction (TESE).

Result(s): The mean TUNEL-positive level was 24.5% for ejaculated sperm, and 4.6% for testicular sperm. Clinical pregnancy was achieved in the first ART cycle with testicular sperm in 12 (50%) out of 24 couples. There was no statistically significant difference in maternal and paternal age, maternal gravity and parity, number of previous ART attempts, concentration or motility of retrieved sperm, number of oocytes retrieved, fertilization rate, or number of embryos transferred between couples who did and did not achieve pregnancy. No miscarriages occurred. All 12 pregnancies resulted in the delivery of healthy children.

Conclusion(s): The percentage of TUNEL-positive cells is lower in testicular sperm for oligospermic men who have abnormal ejaculated sperm DNA fragmentation. The use of testicular sperm for ICSI was associated with a 50% pregnancy and live-birth rate for couples who had previously failed one or more IVF-ICSI cycles with ejaculated sperm. No other clinical predictors of successful pregnancies after the use of surgically retrieved sperm could be identified. In men with elevated TUNEL-positive ejaculated sperm and failed ART, TESE may be considered.