Misconceptions about falling sperm counts and fertility in Europe

Abstract

The Science Policy Briefing on male reproductive health published by the authoritative European Science Foundation (ESF) in 2010 echoes the views expressed in the famous paper by Carlsen et al., suggesting that mean sperm counts decreased by 50%. The authors are convinced that the male reproductive system in industrialized countries is under attack from environmental chemicals. This may have far-reaching consequences for the reproductive capacity of future generations. Their arguments, however, contain some misconceptions about declining sperm quality and fertility. Although there is reason for concern about the effect of environmental pollution, the authors' pessimism is not justified. The authoritative ESF aims to provide a common platform to advance European research collaboration and explore new directions for research improving the wellbeing of European citizens. To this end, so-called Science Policy Briefings are regularly published. The September 2010 issue is entitled Male Reproductive Health—Its Impact in Relation to Gneral Wellbeing and Low European Fertility Rates.1 The chief executive of ESF and the chairman of the European Medical Research Council write in their foreword: ‘This Science Policy Briefing is the first to highlight this important issue which could have a dramatic impact on future birth rates and demographic changes in industrialised countries'. Apparently, the authors of this Policy Briefing—six renowned experts in the field of toxicology, reproductive biology and environmental pollution—are convinced that the male reproductive system in industrialized countries has been and still is under attack by environmental chemicals. The decline in sperm quality and the increasing prevalence of genito-urinary abnormalities such as testicular cancer, cryptorchidism and hypospadias are part of the so-called ‘testicular dysgenesis syndrome' which has a common environmental aetiology and is caused by in utero exposure to high levels of ‘endocrine disrupting chemicals'. The authors believe that these perturbing exposures may have far-reaching consequences for the reproductive capacity of future generations, the first signs of which are already apparent. To preclude disaster, extensive, international researches followed by preventive actions are mandatory. Surprisingly, this policy briefing on male reproductive health contains some misconceptions and fallacies about declining sperm quality and fertility. Apart from scientific arguments, strong beliefs seem to play a role in the discussion of whether or not male reproductive health is at risk in Europe. The contents and arguments used in the report lean heavily on the work of the corresponding author and his Danish research group. This policy briefing is in fact a concise outline of the views and concepts of their research as published in numerous papers. Hence we use some characteristic passages as the starting-point of the misconceptions discussed. First we will give some background information on reproduction, fecundity and fertility.