title: Sperm Chromatin Dispersion Test before Sperm Preparation Is Predictive of Clinical Pregnancy in Cases of Unexplained Infertility Treated with Intrauterine Insemination and Induction with Clomiphene Citrate.
abstract: OBJECTIVE
  A large proportion of men with normal sperm results as analyzed using conventional techniques have fragmented DNA in their spermatozoa. We performed a prospective study to examine the incidence of DNA fragmentation in sperm in cases of couples with previously unexplained infertility and treated with intrauterine insemination. We evaluated whether there was any predictive value of DNA fragmentation for pregnancy outcome in such couples.
  
  
  METHODS
  The percentage of DNA fragmentation and all classical variables to evaluate sperm before and after sperm treatment were determined. We studied the probable association between these results and pregnancy outcome in terms of clinical and ongoing pregnancy rate per started first cycle. We also assessed the optimal threshold level to diagnose DNA fragmentation in our center.
  
  
  RESULTS
  When using threshold levels of 20, 25, and 30%, the occurrence of DNA fragmentation was 42.9, 33.3, and 28.6%, respectively. Receiver operating characteristic (ROC) analysis of all cases revealed an area under the curve of 80% to predict the clinical pregnancy rate per cycle from testing the sperm motility (a + b) before treatment. We failed to generate an ROC curve to estimate pregnancy outcome from the amount of DNA fragmentation before treatment. However, when selecting only those men with a pretreatment DNA fragmentation of at least 20%, the pretreatment result was statistically different between couples who achieved a clinical pregnancy and those who did not.
  
  
  CONCLUSIONS
  DNA fragmentation is often diagnosed in couples with unexplained infertility. Each center should evaluate the type of test it uses to detect DNA fragmentation in sperm and determine its own threshold values.
authors.affiliation: Centre for Reproductive Medicine, University Hospital , Ghent , Belgium.
authors.forename: Frank W R C
authors.initials: FW
authors.lastname: Vandekerckhove
authors.affiliation: Centre for Reproductive Medicine, University Hospital , Ghent , Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: De Croo
authors.affiliation: Centre for Reproductive Medicine, University Hospital , Ghent , Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Gerris
authors.affiliation: Centre for Reproductive Medicine, University Hospital , Ghent , Belgium.
authors.forename: Etienne
authors.initials: E
authors.lastname: Vanden Abbeel
authors.affiliation: Centre for Reproductive Medicine, University Hospital , Ghent , Belgium.
authors.forename: Petra
authors.initials: P
authors.lastname: De Sutter
keywords: DNA fragmentation; chromatin dispersion test; in vitro fertilization; oxygen radicals; receiver operating characteristic