Cigarette smoking and semen quality in men of reproductive age.

The effect of cigarette smoking on conventional semen parameters was studied in voluntary men of reproductive age (n = 190). Special attention was focused on sperm motility and its quantitative and qualitative change in vitro during the observation period. The sperm output war normal in both smokers (n = 54) and non-smokers (n = 110), but semen volume was smaller (p less than 0.03) in heavy smokers (greater than 16 cigarettes/day) than non-smokers. In sperm morphology there was no difference between study groups. The only clear difference between men with different smoking habits was in the percentual change in the sperm motility during 24 hours. At the time of first examination, the sperm motility was better (p less than 0.02) in heavy smokers than those who smoked less than 16 cigarettes per day and the motility decreased more rapidly (p less than 0.007) in heavy smokers than non-smokers. The objectively measured initial mean velocities of the whole sperm population and of the progressive spermatozoa were slightly higher in subgroup of smokers than in non-smokers. The rapid decrease in the survival spermatozoa in smokers may be uneconomical and harmful in respect of fertility.