Smoking is clearly one of the causes of low sperm count and
infertility. Men who smoke not only have poorer sperm quality than nonsmokers, but also
have lower sex drives and less frequent sex, investigators
reported at the joint annual meeting of the American Society for Reproductive Medicine and the Canadian
Fertility and Andrology Society, held in Toronto.
Dr. Panayiotis Zavos, professor of
reproductive physiology and andrology, University of
Kentucky, Lexington, and colleagues at other centers
recruited 290 couples undergoing evaluation for
infertility at the Andrology Institute of America. On
their initial visit, couples were asked to complete a
questionnaire detailing their smoking habits, and their
marital and sexual history, including how often they had
sex and their level of sexual satisfaction.
"In all couples that participated in
this study on infertility and causes of low sperm count, the females were nonsmokers," the
investigators note. In contrast, in 158 couples, the male partners
smoked at least 30 cigarettes a day and had smoked for
more than 7 years.
Results from the questionnaire revealed
that where the male partner smoked, the couple had been
trying to conceive for 3.1 years compared with 2.6 years
for nonsmoking couples, an observation that researchers
felt was "biologically significant."
Smokers also reported having sex only
5.7 times per month compared with nonsmokers who had sex
11.6 times per month. "This is a very dramatic effect,"
Zavos told Reuters Health.
Nonsmoking couples also reported
significantly greater satisfaction with their sex life,
giving it an 8.7 on a scale of 0 to 10, 10 being
"extremely satisfactory." In contrast, smoking couples
gave their sex life a 5.2 rating on the same scale, the
Results from semen analyses also
revealed the quality of spermatozoa from nonsmokers was
superior to that of smokers both in terms of sperm
viability and longevity, indicating clearly that smoking is one of the causes of low sperm count.
Investigators do not yet understand how
smoking affects both the quality of sperm and the male's
sexual habits, but they postulate that smoking might
impair spermatogenesis secondary to various hormonal
alternations caused by smoking. Alternatively, toxic
substances from cigarette smoke may end up in the seminal
"The irony here is that it costs up to
$40,000 in the US for couples seeking infertility
treatment and they still smoke," said Zavos. It also does
not help if the woman herself is a nonsmoker, he added,
because if she co-habits with a smoker, "she's a smoker,
"The cheapest and most efficient way of
improving infertility difficulties is to quit smoking,"
affirmed Zavos. "And if (couples) stop smoking
immediately, that would probably be the first gesture
(they could take) towards treatment for infertility and causes of low sperm count."
Source: Reuters Health, 29 September