title: Intra-individual variation in sperm chromatin structure assay parameters in men from infertile couples: clinical implications.
abstract: BACKGROUND
  Sperm DNA integrity is an important factor in the prognosis of male fertility. In this study, we investigated intra-individual variation of sperm chromatin structure assay (SCSA) parameters in infertility patients undergoing assisted reproductive techniques (ARTs).
  
  
  METHODS
  Retrospective study of 282 consecutive patients referred for ART [intrauterine insemination (IUI), IVF or ICSI] with repeated (between 2 and 5) SCSA measurements.
  
  
  RESULTS
  Mean coefficient of variation (CV) of DNA Fragmentation Index (DFI) for repeated SCSA measurements was 29%. A high proportion [37%; 95% confidence interval (CI): 27%, 49%] of patients with DFI >30% in the first test had DFI <30% in the second test. Also, a considerable proportion (27%; 95% CI : 16%, 40%) of patients with 21-30% DFI values in the first test had DFI >30% in the second test.
  
  
  CONCLUSIONS
  Intra-individual variability in DFI is significant, therefore repeated SCSA measurements are recommended. The biological mechanisms behind these variations remain to be elucidated.
authors: Fertility Centre, Malmö University Hospital, Lund University, Malmö, Sweden. juris.erenpreiss@med.lu.se
authors: J
authors: J
authors: Erenpreiss
authors: M
authors: M
authors: Bungum
authors: M
authors: M
authors: Spano
authors: S
authors: S
authors: Elzanaty
authors: J
authors: J
authors: Orbidans
authors: A
authors: A
authors: Giwercman