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Sperm chromatin structure assay as an independent predictor of fertility in vivo: a case-control study.

Date: 10-15-2009

Giwercman A, Lindstedt L, Larsson M, Bungum M, Spano M, Levine RJ, Rylander L.  Reproductive Medicine Centre, Malmö University Hospital, Lund University, Malmö, Sweden.   Int J Androl. 2009 Oct 15. [Epub ahead of print]

SUMMARY: Men with normal semen values were analyzed by the SCSA test.  As compared with men with a DFI <10%, men with a DFI between 10% and 20% had a 2.5 X  increased risk for infertility.  For men with a DFI > 20% the risk for infertility was 5 times greater than for men with a DFI < 10%. However, if one the standard semen parameters was abnormal and the %DFI >10%, the risk for infertility was 16 times greater compared to a man with normal semen values and a DFI <10%.  The authors concluded “that SCSA DFI adds to the value of semen analysis in prediction of the chance of natural conception”.

FULL SUMMARY OF PAPER. Standard sperm parameters have a limited power for prediction of the chance of natural conception. Recent studies have indicated that the sperm chromatin structure assay (SCSA) DNA fragmentation index (DFI), a measure for the fraction of sperms with DNA damage, is associated with fertility in vivo. The aim of this study was to evaluate the value of this parameter for prediction of infertility. One hundred and twenty-seven men from infertile couples with no known female factor and 137 men with proven fertility were included. Semen analysis was performed as recommended by the WHO. DFI was assessed using SCSA. Logistic binary regression was used to compute the odds ratios (OR) for infertility. As compared with men with a DFI <10%, men with a DFI between 10% and 20% had an increased risk for infertility (OR 2.5, 95% CI: 1.0-6.1). This was also true for men with a DFI >20% (OR 8.4; 95% CI: 3.0-23). In men with normal standard semen parameters (sperm concentration, motility and morphology) the OR for infertility was increased with DFI >20% (OR 5.1, 95% CI: 1.2-23), whereas if one of the standard semen parameters was abnormal, the OR for infertility was increased already at DFI above 10% (OR 16, 95% CI: 4.2-60). We conclude that SCSA DFI adds to the value of semen analysis in prediction of the chance of natural conception.

DPE: This manuscript and others as well as our SCSA clinical feedback is what has prompted us to reduce the Good to Fair category by 5% to <25%  with the resulting Fair to very poor category from 25 to >35%

DNA Fragmentation Index (% DFI; % sperm cells containing measurable DNA damage)
a. ≤ 15% DFI = Excellent to Good sperm DNA integrity
b. 15 to < 25% DFI = Good to Fair sperm DNA integrity
c. 25 to ≥ 35% DFI = Fair to Very Poor sperm DNA integrity
Note: The above values relate to natural and IUI conception.