Is sperm DNA integrity assessment useful?

YES of the dye or enzyme to the sites of damaged DNA) 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 TESTS of sperm DNA integrity have been used increasingly in the evaluation of the infertile man. These tests have been developed to further our understanding of spermatogenesis and sperm function, and to potentially provide a more accurate infertility diagnosis than by evaluation of standard sperm parameters alone. Conventional sperm parameters such as sperm concentration, motility and morphology exhibit a high degree of biological variability and are only fair measures of fertility potential. Sperm DNA integrity tests have also been developed in the hope that they may predict pregnancy outcome after assisted reproductive technologies (ARTs), as conventional sperm parameters are poor predictors of ART outcomes. Animal models have played a major role in providing strong evidence that sperm DNA fragmentation is highly correlated with male fertility potential. Moreover, experimental studies have demonstrated that sperm DNA damage is associated with poor reproductive outcomes (lower pregnancy rates, chromosomal abnormalities, pregnancy loss, reduced longevity and birth defects) after ARTs. These experiments have raised some concerns regarding the use of DNA damaged sperm in the context of ARTs. However, these observations may or may not translate to equivalent clinical effects because unlike sperm DNA damage in humans, DNA damage in animal models is induced experimentally and is present in all spermatozoa. Several assays have been developed to measure sperm DNA and chromatin damage. The most common are SCSA (sperm chromatin structure assay), COMET (single cell gel electrophoresis) assay, TUNEL (Terminal deoxynucleotidyl transferasemediated dUTP Nick End-Labeling) assay and SCD (sperm chromatin dispersion) assay. It is important to consider that some assays have undergone more rigorous testing than others, that different assays measure different aspects of sperm DNA and chromatin integrity, and that these assays do not selectively differentiate clinically important from insignificant damage. Moreover, sample preparation and handling, and assay conditions (eg accessibility