SEMEN PARAMETERS IN A FERTILE VERSUS SUBFERTILE POPULATION - A NEED FOR CHANGE IN THE INTERPRETATION OF SEMEN TESTING

This prospectively designed study was conducted to compare a fertile a nd a subfertile population so as to define normal values for different semen parameters, Semen analyses were performed according to the Worl d Health Organization (WHO) guidelines, except for sperm morphology (s trict criteria), In the fertile population (n = 144), all patients had recently achieved pregnancy, within 12 months of unprotected coitus, As subfertile controls we examined semen samples from 143 consecutive men attending our infertility clinic during the same study period, Cou ples with tubal factor infertility and/or ovulatory disorders were exc luded from our study, Using receiver operating characteristic (ROC) cu rve analysis we determined the diagnostic potential and cut-off values for single and combined sperm parameters, Sperm morphology scored bes t, with a value of 78% (area under the ROC curve), Summary statistics showed a shift towards abnormality for most semen parameters in the su bfertile population, Using the 10th percentile of the fertile populati on as the cut-off value, the following results mere obtained: 14.3 x 1 0(6)/ml for sperm concentration, 28% for progressive motility and 5% f ar sperm morphology. Using ROC analysis, cutoff values were 34x10(6)/m l, 45% and 10% respectively, Cut-off values for normality were differe nt from those described in the WHO guidelines, Routine bacterial and n on-bacterial cultures turned out to be of little prognostic value.