Regional differences in semen qualities in the Baltic region

Abstract

Recent prospective studies of male reproductive health have shown differences between several European countries. Our objective was to evaluate the current situation in the two Baltic States Estonia and Lithuania. In 1997-99 we investigated semen parameters, levels of reproductive hormones and general health factors of 196 men from the general population in Lithuania; from Estonia, 79 men from the general population and 118 soldiers were investigated. Adjusted for interlaboratory differences and abstinence period, sperm concentration of Lithuanian and Estonian men from the general populations were shown to be 55 and 67 million/mL, respectively. The Estonian soldiers had the highest sperm concentration, 82 million/mL. The frequencies of morphologically normal spermatozoa were 6.2, 7.7 and 9.6%, respectively. In contrast to the semen qualities, highest Inhibin B levels were detected in the Lithuanians (233 pg/mL) followed by Estonian men from the general population (220 pg/mL) and Estonian soldiers (185 pg/mL). The soldiers had also the lowest level of testosterone and oestradiol. The sperm counts of the Estonian and Lithuanian men investigated here are higher than recently shown for Norwegian, Danish, Estonian and Finnish men. Comparisons should be cautiously drawn as the groups are not completely comparable. Still, even within the Baltic region, geographically close and sharing common recent social history, differences in semen quality and levels of reproductive hormones are apparent.

Semen quality analysis of military personnel from six geographical areas of the People’s Republic of China

“…declineing trend in sperm concentration others have failed to detect a temporal trend (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), with the contradictory results variously attributed to sample selection bias, regional differences and/or experimental error (16)(17)(18)(19).…”

“…To our knowledge, most studies were based on subjects who were long-term or permanent residents of a region andor were recruited from the general population (10,19). With globalization of the world economy, population mobility has been increasing rapidly and by 2007 it was estimated that there were estimated to be 120 million internal migrants in China (20).…”

‘Carriers of V‐LH among 1593 Baltic men have significantly higher serum LH’

“…Study participation was voluntary and written informed consent was obtained from all subjects. Details of the study group formation were described previously (Punab et al ., 2002). Men were recruited to the study at the Centre of Andrology, University Clinic of Tartu, Estonia ( n  = 578; all born and living in Estonia), at the Riga Family and Sexual Problems Centre, Latvia ( n  = 300; all born and living in Latvia) and at the specialized laboratory of the Institute of Endocrinology, Kaunas University of Medicine ( n  = 326; all born and living in Lithuania).…”

“…Oligozoospermia was diagnosed according to the World Health Organization (WHO) criteria valid at the time of recruitment (sperm concentration < 20 mln/mL; World Health Organization, 1999). Phenotyping protocol was identical with that in Baltic young male cohort (Punab et al ., 2002); the details of the formation of the study group are described elsewhere (Punab, 2007). In brief, all study participants were of white European ancestry, born and living in Estonia.…”

Ignorance but not bliss: too little is known about the determinants of semen quality

“…There is variation in semen between different regions of France, 39 and different European cities (Copenhagen, Paris, Edinburgh and Turku), 40 although these differences were not correlated with time to pregnancy in these cities, 41 the Baltic states 42 and the United States. 43 It is not yet clear whether these differences are due to genetic or to environmental differences and recruitment bias is difficult to exclude.…”