Regional differences in semen quality in Europe

Abstract

Recent reports have indicated a decrease in semen quality of men in some countries, and suggested regional differences. A study was undertaken of semen samples from 1082 fertile men from four European cities (Copenhagen, Denmark; Paris, France; Edinburgh, Scotland; and Turku, Finland). Semen analysis was standardized, inter‐ laboratory differences in assessment of sperm concentration were evaluated, and morphology assessment centralized. Lowest sperm concentrations and total counts were detected for Danish men, followed by French and Scottish men. Finnish men had the highest sperm counts. Men from Edinburgh had the highest proportion of motile spermatozoa, followed by men from Turku, Copenhagen and Paris. Only the differences between Paris/Edinburgh and Paris/ Turku were statistically significant (P < 0.003 and P 0.002 respectively). No significant differences in morphology were detected. A general seasonal variation in sperm concentration (summer 70% of winter) and total sperm count (summer 72% of winter) was detected. Semen quality of a ‘standardized’ man (30 years old, fertile, ejaculation abstinence of 96 h) were estimated. Topically, sperm concentrations (x 106/ml) for winter/summer were: Turku 132/93; Edinburgh 119/84; Paris 103/73; and Copenhagen 98/69. These differences in semen quality may indicate different environmental exposures or lifestyle changes in the four populations. However, it remains to be seen whether such changes can account for these differences. These data may also serve as a reference point for future studies on time trends in semen quality in Europe.

Decline of semen quality among 10 932 males consulting for couple infertility over a 20-year period in Marseille, France

“…49 It is important to emphasize the marked geographical differences in the last secular trend in male reproductive function. [50][51][52] The explanation for this regional trend is not known. Giwercman and LundgergGiwercman 46 argue that the population may genetically differ, but that probably environmental or life style related factors are operating.…”

“…Nevertheless, the observed discrepancies between studies suggest regional differences in semen quality. [20][21][22] Variations in environmental factors, industrial pollution and/or lifestyle could explain these discrepancies. A large number of environmental factors can pollute air, drinking water and food.…”

Misconceptions about falling sperm counts and fertility in Europe

“…These questions prompted an unprecedented, prospective and coordinated action in Finland, Denmark, Scotland and France in which sperm parameters were related to couple fecundity-almost 1000 couples took part. [42][43][44] The results of the combined data of the four countries demonstrated an overall trend of a relation between increasing sperm concentrations up to about 50 million per ml with shorter times to pregnancy corresponding with better fecundity. However, the results also revealed that the relation between sperm concentration and couple fecundity was far from straightforward.…”

Reference limits: limited references in laboratories worldwide

“…Previous data from screened and general populations showed that there are obvious differences in semen quality between continents [6], countries [7] and even different areas in the same country [6,8,9]. Some of the studies also revealed temporal differences [10].…”

“…Profound comments on this regard have been made and published in the Special Issue in Asian Journal of Andrology on "Semen analysis in 21st Century Medicine" in Issue 1 in 2010 [2][3][4][5]. In this letter, I would like to present some of my views and suggestions on reference limits of semen parameters.Previous data from screened and general populations showed that there are obvious differences in semen quality between continents [6], countries [7] and even different areas in the same country [6,8,9]. Some of the studies also revealed temporal differences [10].…”