Changing Tendency Analysis of Chinese Normal Male's Semen Quality in Recent 25 Years: Samples from Chinese Documents

To analyze the trend of change in semen quality of Chinese healthy men over recent 25 years. A total of 115 reports were collected on quality inspection of semen of healthy Chinese men between 1985–2009 through literature search, which involved 23 126 persons from 69 counties and cities. Trend of change in semen parameters was analyzed by linear regression model and rank sum test. Sperm concentration and non-progressive motility (c%) declined, and the linear equation was of statistics value. Linear equations include y = 2.968−0.004x (P<0.05) and y = 3.204−0.026x (P<0.05). As the results of K-S rank sum test showed, the difference of sperm concentration and total sperm count in the three groups, i.e., the group for 1985–1989, the group for 1990–1999 and the group for 2000–2009 was of statistics value. The semen concentration of healthy Chinese men appears a possible decline over recent 25 years (P<0.05).