Semen quality in young men has been clearly declining over the past 15 years

First study to examine a very large population of sperm donors within the same laboratory over a long observation period

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January 2017 Study Abstract

To provide information of semen quality among young Chinese men in the past 15 years.

Retrospective cross-sectional study.

Sperm bank.

A total of 30,636 young adult men who applied to be sperm donors at the Hunan Province Human Sperm Bank of China in 2001–2015 were included in the study.

Decline in semen quality among 30,636 young Chinese men from 2001 to 2015, Fertility and Sterility:, January 2017 (Volume 107, Issue 1), Pages 83–88.e2.

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Physical examination and analysis of blood and semen samples.

Main Outcome Measure(s)
Semen parameters, such as semen volume, sperm concentration, total sperm count, progressively motile sperm count, sperm progressive motility, sperm morphology, and round cells.

Many of the semen parameters showed a decreasing trend over the 15-year observation period. The sperm concentration and percentage of sperm with normal morphology decreased from 68 × 106/mL to 47 × 106/mL and from 31.8% to 10.8%, respectively. Although sperm progressive motility showed irregular variation, the progressively motile sperm count decreased from 34 × 106 to 21 × 106 over the 15-year period. Furthermore, the rate of qualified donors fell from 55.78% in 2001 to 17.80% in 2015, and the rate for 2015 was approximately threefold lower than the corresponding rates in 2001.

This is the first study to investigate the semen quality of a large population within the same laboratory in China over a long observation period. Our data clearly illustrate that the semen quality among young Chinese men has declined over a period of 15 years, especially in terms of sperm concentration, total sperm count, sperm progressive motility, and normal morphology. Moreover, the percentage of qualified donors also showed a decreasing trend during this time period. Although bulk semen parameters (reflected by 95% confidence intervals) overlap substantially throughout the study period, overall, these findings are a serious reproductive health warning, and further studies are warranted to confirm the findings of this study in China and to determine the factors causing this phenomenon.

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