Semen quality of male smokers and nonsmokers in infertile couples

To investigate the effect of cigarette smoking on main sperm variables. Cohort study. Men attending the andrology laboratory in the context of infertility investigation in the couple. Eight hundred thirty-nine smokers and 1,266 non-smokers were enrolled; 655 smokers and 1,131 nonsmokers fulfilled the inclusion criteria and were compared. Standard clinical analysis of semen. Cigarette smoking was associated with a significant decrease in sperm density (−15.3%), total sperm count (−17.5%), total number of motile sperm (−16.6%), and citrate concentration (−22.4%). The percentage of normal forms was significantly reduced in smokers, and sperm vitality, ejaculate volume, and fructose concentration were slightly but nonsignificantly affected. Cigarette smoking is associated with reduced semen quality.