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, 39.4×10(6) per mL for sperm concentration, 120.1×10(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.