Smoking
can have adverse effect on semen quality, and may consequently
cause a reduction in male fertility, research confirms.
"Many studies have suggested that cigarette smoking is associated with altered
semen quality, but conclusions about the extent of the deleterious effects vary
widely," write Dr. Nick Bersinger (University of Berne, Switzerland) and
co-authors. Postulating small study sizes and differences in the thresholds used
to define smokers and non-smokers could explain this variation, the researchers
studied a large group of men in whom the definition of "smokers" was
strict (1 or more cigarette per day).
The study included 655 smoking and 1,131 non-smoking men, who completed a questionnaire
including questions on age, alcohol use, and reproductive history. Semen samples
were collected for analysis from each participant.
Cigarette smoking was associated with a significant decrease in sperm density,
sperm count, number of motile sperm, and citrate concentration. Sperm morphology
was also adversely affected by smoking.
The researchers conclude that, while sperm variables in
smokers may remain in the normal range, a "clear negative trend is observed." Accordingly, "men
with borderline semen quality who wish to have children should especially benefit
from quitting smoking," they suggest.
Source: Fertility
and Sterility 2003; 79: 287-91, 3 March 2003
Infertility