Background: The aim of this prospective study was to analyse the different sperm parameters of fertile Swiss men. To date there are no data regarding the quality of spermatozoa of fertile Swiss men.
Methods: We measured the ejaculates (pH, volume, concentration, motility, viability, morphology) of 34 men using strict inclusion criteria. The partners of these men had to be pregnant at the time of inclusion in the study and these pregnancies had to have been conceived spontaneously within 15 months. A questionnaire elucidated the consumption of alcohol, nicotine and drugs. Semen analysis was performed according to WHO-criteria, with the exception of morphology, which was analysed according to Tygerberg's strict criteria.
Results: The mean age of the males studied was 34 years. The semen analysis revealed the following following mean values: pH: 8, volume: 2.6 ml, concentration: 60 x 10(6)/ml, total count: 160 x 10(6), progressive motility: 42%, rapid progressive motility: 36%, viability: 47% and morphology: 8% normal forms. The consumption of alcohol, nicotine and drugs was low to moderate.
Conclusions: No men fulfilled all criteria of normality in the different sperm parameters examined. The most striking results are that the upper limits of normal morphology and viability seem to be too high. Concentration and rapid progressive motility appear to have a high impact on fertility. The combination of several criteria is probably more predictive than a single parameter.