Abstract
Objective: To evaluate the changes of conventional sperm parameters in men who referred to an andrology reference center in Catania (Eastern Sicily, Italy) in the decade 2011–2020. Methods: For this purpose, we selected–retrospectively and randomly–the reports of 1409 semen analyses performed according to the 2010 WHO criteria. Data on sperm concentration, total sperm count, progressive sperm motility, and percentage of normal forms were analyzed using linear regression of the raw and logarithmic-transformed data. The sperm parameters were subsequently pooled in two five-year periods (2011–2015 and 2016–2020) and compared with each other. Finally, the influence of the city of residence was assessed on five-year pooled data. Main results: A slight but non-significant decline of total sperm count (−2.26 million/year; p = 0.065) and the percentage of spermatozoa with normal morphology (−0.08%/year; p = 0.057) was observed. In contrast, a significant increase of progressive sperm motility (+0.28%/year; p = 0.008) over time was found. The total sperm count of the quinquennium 2016–2020 was significantly lower. and an upward trend of progressive sperm motility was found. compared to the years 2011–2015. No changes in sperm concentration and morphology occurred in the years 2011–2015 vs. 2016–2020. Sperm conventional parameters did not differ when the five-year pooled data were analyzed according to the town of residence. Conclusions: Divergent trends of total sperm count and progressive sperm motility over time were found in patients from Eastern Sicily. This may point out the need of assessing whether a time-dependent change of biofunctional sperm parameters occurs to really understand the trend of sperm quality over time.
Highlights
The first analyzed data from nearly 43,000 men showed a decline of 52.4% of sperm concentration and 59.3% of total sperm count between 1973 and 2011 among unselected men living in Western countries (North America, Europe, Australia, and New Zealand)
Linear regression analysis of the raw data revealed that sperm concentration did not change over time, but total sperm count showed a downward trend (−2.26 million/year; p = 0.065)
Semen volume showed a significant decline through decades, whereas seminal fluid pH significantly increased, it remained in the normal range (Table 1)
Summary
Whether a temporal trend toward a decline of the sperm quality really exists is still a matter of debate, since both supporting [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15] and opposing [16,17,18,19,20,21,22,23,24,25] evidence has been published so far. Two meta-regression studies collecting data from hundreds of people from several countries have been carried out in an attempt to resolve conflicting evidence. The first analyzed data from nearly 43,000 men showed a decline of 52.4% of sperm concentration and 59.3% of total sperm count between 1973 and 2011 among unselected men living in Western countries (North America, Europe, Australia, and New Zealand). Such a decline was not observed in men from South America, Asia, and Africa [26]. The presence of a sperm-parameter decline throughout the decades has been described in Asian countries [28,29] (Supplementary Table S1), contradicting the findings of the first meta-analysis and making arduous the interpretation of the results
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
