[Spermiologic parameters in Czech men from 1950 to 1984 (analysis of data from the archives of the Sexology Institute of the First Medical School of Charles University and the General Medical School Hospital in Prague].
Reports maintaining that sperm concentration in male ejaculates had decreased markedly over the past decades captured mind-share all over the world. However, literary data diverge about such a lasting trend. Our objective has been to contribute to the ongoing debate by presenting results of our own research. We have studied semen analyses of 5,363 men who had been tested at an outpatient care unit of the Prague Institute of Sexology between 1950 and 1984. These semen analyses measured volume of the ejaculate, sperm concentration, sperm motility, and a share of sperms with morphological abnormalities. None of these values showed statistically significant deterioration among seven groups of patients, each spanning five years. Therefore, our data did not confirm the above-mentioned lasting trend in semen analysis values. Research teams from all over the world have recently attracted a lot of attention by reporting a no-table decrease over the past decades in sperm concentration in the male ejaculates. However, literary data diverge about such a lasting trend. Our objective has been to contribute to the ongoing debate by presenting results of our own research. We have analysed semen tests filed in the archives of the Institute of Sexology at the 1st Faculty of Medicine of Charles University. We have studied a set of 5,363 men who had undergone their first sperm analysis between 1950 and 1984. We have gathered our data from medical records, using a uniform pattern of investigation. The set was divided into seven five-year groups based on the year of the first analysis. Volume of the ejaculate: The groups showed the following average volume of the ejaculate: 3.9-3.8-3.8-3.8-3.8-3.7-3.7 (ml). Neither the distribution nor the mean value of this variable has changed much over time. Sperm concentration: The groups showed the following mean sperm concentration: 32.9-42.3-56.2-57.9-72.2-70.8-72.3 (million per ml). It is obvious from these results that the mean sperm concentration increased over time in our set. Sperm motility: The groups showed the following mean sperm motility: 34.7-46.4-53.3-57.7-59.6-58.5-58.2 (per cent). Sperm morphology: The share of ejaculates with a high percentage of morphologically abnormal sperm cells has not grown much. Our data did not confirm the hypothesis that sperm analysis results have been gradually worsening. We have not found deteriorating trends in any of the sperm quality measures in the five-year intervals between 1950 and 1984. Although our results cannot close the debate about purported deterioration of sperm analysis results, they seem to indicate that we should take reports of universal decrease in sperm concentration in the seminal fluid with a grain of salt.