Many hypotheses have been put forward to explain a suspected decline in semen quality. Up to now many sources of data were used but conflicting results are present in the literature. To study whether modifications of sperm parameters actually exist we used data from two groups of patients checked and two small groups of sperm bank donors selected at the beginning ’80s and ’90s. We tried to reduce bias to a minimum: all the semen analyses were carried out by the same biologist, using the same methods, groups were clinically evaluated by the same andrological team, the study groups were homogeneous for age, geographic-ethnic origin, residence, monthly-seasonal distribution and abstinence period. Comparing patients from the ’80s and the ’90s, sperm concentration and motility showed a significant reduction. Furthermore, the decrease in concentration and motility was mainly due to the higher age classes. In donors, no decline was observed. These results seem to indicate that sperm donors remain unaffected, while patients with lower levels of semen quality are experiencing a real decline. Unfortunately, many confounding variables, analyzed in detail in this review, still remain despite efforts at standardization.
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Carlsen E., Giwercman A., Keiding N., Skakkebæk N.E. Evidence for decreasing quality of semen during past 50 years. Br. Med. J. 1992, 305: 609–612.
Keiding N., Giwercman A., Carlsen E., Skakkebæk N.E. Falling sperm quality. Br. Med. J. 1994, 309: 131.
Olsen G.W., Bodner K.M., Ramlow J.M., Ross C.E., Lipshultz L.I. Have sperm counts been reduced 50 percent in 50 years? A statistical model revisited. Fertil Steril. 1995, 63: 887–893.
Fisch H., Goluboff E.T. Geographic variations in sperm counts: a potential cause of bias in studies of semen quality. Fertil. Steril. 1996, 65: 1044–1046.
Becker S., Berhane K. A meta-analysis of 61 sperm count studies revisited. Fertil. Steril. 1997, 67: 1103–1108.
Auger J., Kunstmann J.M., Czyglik F., Jouannet P. Decline in semen quality among fertile men in Paris during the past 20 years. N. Engl. J. Med. 1995, 332: 281–285.
Bujan L., Mansat A., Pontonnier F., Mieusset R. Time series analysis of sperm concentration in fertile men in Toulouse, France between 1977 and 1992. Br. Med. J. 1996, 312: 471–472.
Van Waeleghem K., De Clercq N., Vermeule L., et al. Deterioration of sperm quality in young healthy Belgian men. Hum. Reprod. 1996, 11: 325–329.
Wittmaack F.M., Shapiro S.S. Longitudinal study of semen quality in Wisconsin men over a decade. Wis. Med. J. 1992, 91: 477–479.
Fisch H., Feldshuh J., Goluboff E.T., Olson J.H., et al. Semen analyses in 1283 men from the United States over a 25-year: no decline in quality. Fertil. Steril. 1996, 65: 1009–1014.
Paulsen C.A., Berman N.G., Wang C. Data from men in greater Seattle area reveals no downward trend in semen quality: further evidence that deterioration of semen quality is not geographically uniform. Fertil. Steril. 1996, 65: 1015–1020.
Irvine S., Cawood E., Richardson D., et al. Evidence of deteriorating semen quality in the United Kingdom: birth cohort study in 577 men in Scotland over 11 years. Br. Med. J. 1996, 312: 467–471.
Rasmussen P.E., Erb K., Westergaard L.G., Laursen S.B. No evidence for decreasing semen quality in four birth cohorts of 1,055 Danish men born between 1950 and 1970. Fertil. Steril. 1997, 68: 1059–1064.
Adamopulos D.A., Pappa A., Nicopoulou S., et al. Seminal volume and total sperm number trends in men attending subfertility clinics in the Greater Athens area during the year 1977–1993. Hum. Reprod. 1996, 11: 1936.
Vierula M., Niemi M., Keiski A., et al. High and unchanged sperm counts of Finnish men. Int. J. Androl. 1996, 19: 11–17.
Berling S., Wölner-Hanssen P. No evidence of deteriorating semen quality among men in infertile relationships during the last decade: a study of males from Southern Sweden. Hum Reprod 1997, 12: 1002–1005.
Nikkanen V. The effects of vasectomy on viscosity, pH and volume of semen in man. Andrologia 1979, 11: 123–125.
Suominen J., Vierula M. Semen quality in Finnish men. Br. Med. J. 1993, 306: 1579.
Adami H.O., Bergström R., Möhner M., et al. Testicular cancer in nine northern European countries. Int. J. Cancer 1994, 59: 33–38.
Clermont Y. Quantitative analysis of spermatogenesis of the rat: revised model for the renewal of spermatogonia. Am. J. Anat. 1962, 111: 111–119.
Steinberger E., Tjioe D.Y. A method for quantitative analysis of human seminiferous epithelium. Fertil. Steril. 1968, 19: 960–970.
Johnson L., Chaturvedi P.K., Williams J.D. Missing generations of spermatocytes and spermatids in seminiferous epithelium contribute to low efficiency of spermatogenesis in humans. Biol. Reprod. 1992, 47: 1091–1098.
Pajarinen J., Laippala P., Penttila A., et al. Incidence of disorders of spermatogenesis in middle aged Finnish men, 1981–91: two necropsy series. Br. Med. J. 1997, 314: 13–18.
World Health Organization Laboratory Manual for the Examination of Human Semen and Semen-Cervical Mucus Interaction. Cambridge University Press, Cambridge, 1982.
World Health Organization Laboratory Manual for the Examination of Human Semen and Semen-Cervical Mucus Interaction, ed. 2. Cambridge University Press, Cambridge, 1987.
World Health Organization Laboratory Manual for the Examination of Human Semen and Semen-Cervical Mucus Interaction, ed. 3. Cambridge University Press, Cambridge, 1992.
Nelson C.M., Bunge R.G. Semen analysis: evidence for changing parameters of male fertility potential. Fertil. Steril. 1974, 25: 503–507.
Feichtinger W. Enviromental factors and fertility. Hum. Reprod. 1982, 6: 1170–1175.
Sharpe R.M., Skakkebæk N.E. Are oestrogens involved in falling sperm counts and disorders of the male reproductive tract? Lancet 1993, 341: 1392–1395.
Editorial Male reproductive health and enviromental oestrogens. Lancet 1995, 345: 933–935.
Yasuda Y., Kihaja T., Tanimura T. Effect of ethinyl estradiol on the differentiation of mouse fetal testis. Teratology 1985, 32: 113–118.
Figà-Talamanca I., Dondero F., Gandini L., et al. Male infertility and occupational exposures: a casecontrol study. J. Occup. Med. Toxicol. 1992, 1: 255–264.
Forti G., Serio M. Male infertility: is its rising incidence due to better methods of detection or an increasing frequency? Hum. Reprod. 1993, 8: 1153–1154.
Sherins R.J. Are semen quality and male fertility changing? N. Engl. J. Med. 1995, 332: 327–328.
Jørgensen N., Auger J., Giwercman A., et al. Semen analysis performed by different laboratory teams: an intervariation study. Int. J. Androl. 1997, 20: 201–208.
Setchell B.P. Sperm counts in semen of farm animals 1932–1995. Int. J. Androl. 1997, 20: 209–214.
MacLeod J., Gold R.Z. The male factor in fertility and infertility. II. Spermatozoa counts in 1000 men of known fertility and in 1000 cases of infertile marriage. J. Urol. 1951, 66: 436–449.
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Gandini, L., Lombardo, F., Culasso, F. et al. Myth and reality of the decline in semen quality: An example of the relativity of data interpretation. J Endocrinol Invest 23, 402–411 (2000). https://doi.org/10.1007/BF03343745
- Semen quality
- male fertility
- sperm concentration
- sperm motility