Semen quality analysis of military personnel from six geographical areas of the People's Republic of China

Objective: To examine the determinants of semen quality in a large sample of military personnel from different geographical areas of the People's Republic of China. Design: Cross-sectional study. Setting: Six representative geographical regions in China: Beihai, Lhasa, Germu, Xinzhou, Huhehaote, and Mohe. Patient(s): 1,194 army personnel aged 18 to 35 years at the time of their inclusion in the study, sampled between 2007 and 2009. Intervention(s): None. Main Outcome Measure(s): Semen volume (in milliliters), sperm concentration (in millions per milliliter), percentage of motile spermatozoa, total sperm count (in millions), and relative risk of subfertility. Result(s): The median values were 3.0 mL for semen volume, 39.4 x 10(6) per mL for sperm concentration, 120.1 x 10(6) for total sperm count, 15.8% for sperm rapid progressive motility, 30.1% for sperm progressive motility, and 43.9% for total motility. We found that 88.3% of the servicemen had at least one semen parameter below normal values according to World Health Organization (WHO) recommendations (1999), and 62.5% according to WHO recommendations (2010). Season, average altitude, and duration of sexual abstinence all were statistically significantly associated with semen quality. Conclusion(s): The men had markedly lower mean sperm concentrations, sperm counts, and sperm motility compared with WHO recommendations. Possible contributory factors included diet, lifestyle, climate, and altitude. (Fertil Steril (R) 2011; 95:2018-23. (C) 2011 by American Society for Reproductive Medicine.)