BACKGROUND: The sperm chromatin structure assay (SCSA) parameter DNA fragmentation index (DFI) has been shown to predict in vivo and in vitro fertility. So far most SCSA studies have been based on SCSA analysis performed on neat semen. The aim of this study is to assess whether SCSA analysis of sperm prepared by density gradient centrifugation (DGC) could add more information in regard to the prediction of treatment outcome. METHODS: The study included 510 assisted reproductive technique (ART)

more »

... ycles. SCSA was performed in neat semen and post DGC. SCSA results were expressed in terms of DFI and high DNA stainability (HDS) cell fractions. The outcome parameter was clinical pregnancy (CP). RESULTS: Scatter-plot diagrams demonstrated that for DGC samples, no DFI cut-off values could be set for in vivo or in vitro fertility. In intrauterine insemination, IVF and ICSI groups the mean difference (95% CI) in DFI post DGC between those who achieved CP and those who did not was 0.2% (21.7 to 2.0%), 0.4% (21.9 to 2.8%) and 1.3% (23.1 to 5.9%), respectively, none of these being statistically significant. The corresponding differences for HDS were 0.1% (21.3 to 1.5%), 0.1% (20.7 to 0.9%) and 0.6% (21.6 to 2.7%), respectively (all P-values >0.6). CONCLUSIONS: SCSA performed in semen prepared by DGC cannot predict the outcome of ART.