Objective: To investigate the effect of cigarette smoking on main sperm variables.
Design: Cohort study.
Setting: Men attending the andrology laboratory in the context of infertility investigation in the couple.
Patient(s): 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.
Result(s): 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.
Conclusion(s): Cigarette smoking is associated with reduced semen quality.