[Analysis of decline in seminal fluid in the Italian population during the past 15 years].
BACKGROUND AND AIMS: The authors wished to study whether there has been a real decline in the quality of semen over the past years, as reported in the literature by a number of studies. This paper analyses the basic parameters of semen from 1068 males who have acted as donors during the past 15 years (1981-1995) for our semen bank. METHODS: Tables have been drawn up showing the number of cases examined every year, the mean concentration of spermatozoa, the mean percentage of mobile sperm and the mean percentage of non-conforming elements. RESULTS: An analysis of the data reported here shows that the mean concentration of spermatozoa in semen has shrunk from 88 x 10(6)/ml in 1981 to 61 x 10(6)/ml in 1995, a reduction of 30.7%; mean total motility has diminished from 74 to 66%, whereas the mean percentage with typical morphology has fallen from 76 to 63%. No statistical analysis was performed since variance analysis could not be performed on the sample in question to isolate the various sources of error. CONCLUSIONS: In conclusion, there has been a marked fall in the quality of semen over the past few years in individuals who regard themselves as fertile and are selected as semen donors. In the discussion the authors examine the various hypotheses regarding the possible causes of this deterioration in quality, opting for the argument based on the increased use of pollutants during the period in question in urban and rural areas.