Data analysis of two in vivo fertility studies using Sperm Chromatin Structure Assay-derived DNA fragmentation index vs. pregnancy outcome

The 2006 American Society for Reproductive Medicine Compendium of Practice Report found no significant effects of elevated sperm DNA fragmentation by using a 30% DNA fragmentation index (DFI) threshold for natural fertilization and SCSA data (odds ratio, 1.07; 95% confidence interval, 0.39-2.93). In contrast, it is shown in this article that these two in vivo studies showed significant odds ratios of 6.54 (95% confidence interval, 1.71, 24.91) and 7.58 (95% confidence interval, 2.54, 22.67), which resulted in the conclusion that the pregnancy (PG) rates are statistically significantly higher for the group with DFI below the thresholds of 30% and 40%, respectively. In addition, all the chi(2) statistics used to test the null hypotheses of no association between the pregnancy status and DFI for natural (normal) fertilization confirmed this conclusion that the probability of pregnancy for the group with <30% or <40% DFI was statistically significantly higher than that for the group with >30% or >40% DFI.