Analysis of Screening Results of 1012 Sperm Donors in China: A Retrospective Cohort Study of Geographic Differences in Semen Quality

Male reproductive health has become a concern in public health, and semen quality is essential to male reproduction. To investigate the geographical differences in semen quality of sperm donors from the north and south of China, a total of 1012 sperm donors from all over China were enrolled in this work, which were divided by their residential latitude. There were statistically significant differences in sperm concentration among men from different latitudes in China(P=0.04). The sperm concentrations of people from 18°-27° north latitude were lower than those from 36°-45°, and 45°-54° (median 131, 134, 146, respectively, P=0.021[18°-27° vs. 36°-45°] and P=0.01[18°-27° vs. 45°-54°]). It was further confirmed when the samples were re-divided into 2 groups (typically north and south) that contains 667 samples. The analysis also showed a significant difference in terms of the regions to which the samples belonged (the median of the north is 134; the median of the south is 125; P =0.015). Although other sperm parameters don’t show significant change with latitude, some of them possess a strong relationship with sperm concentration ( r =-0.19364, P<0.001). Specifically, we suppose that environmental pollution and mental stress due to increased population may be the main factors in the difference.