Western sperm counts 'halved' in last 40 years

Conclusion This research presented a useful summary of existing studies in the area of human sperm count, and presented some interesting findings relating to trends over time. But this study does have some limitations: The research was based on a wide range of populations who, in some cases, may only have been assessed once. Following a fixed population over time in a cohort study might have had different findings. Research that wasn't published in English wasn't included, and there also aren't many studies published before 1985 from countries in the other category. This might have an effect on whether the estimates from this population are correct, as studies from those countries might be less likely to be published in English. Having fewer studies to draw upon may be why there are no significant trends in this group.  The study looked at sperm count and concentration, not the quality of the sperm itself, because there was limited reporting of this information in older studies. Likelihood of conception depends not only on the amount of sperm but also its quality, so it would be useful to have this information to be able to make predictions about the impact of these findings on fertility rates. The authors didn't report any kind of formal quality assessment of the studies they included in their analysis. Although this research suggests there may be a decline in sperm count in Western countries in recent years, it doesn't offer any explanations. It also doesn'...
Source: NHS News Feed - Category: Consumer Health News Tags: Pregnancy/child Lifestyle/exercise Source Type: news