Smokers' sperm less fertile
MEN who smoke are less likely to make a woman pregnant than
non-smokers, and the more they smoke the worse their chances
are, a new study finds.
Researchers from the American State University at Buffalo School
of Medicine say that male smokers experience changes in their
sperm that make fertilisation difficult.
Lead author Lani Burkman, an associate professor in the
department of gynaecology and obstetrics, said earlier studies
had shown that when nicotine and its byproduct, cotinine, were
added to sperm in the lab, they changed the way the sperm moved.
The smokers' sperm were able to break down the egg wall but they
were much less able to make a good bond.
"If the tail is very weak, it will never push itself rough the
zona," Dr Burkman said.
The study estimated that the sperm of chronic smokers (smokers
of four or more cigarettes a day for at least two years) were on
average 75 per cent less fertile than those of nonsmokers.