Vibha Sachdeva, New Delhi: Smoking during pregnancy can adversely affect the foetus, so women should avoid it, says a study. But now there's a pressing reason for men to quit smoking too and it's linked to DNA damage.

A Canadian study published in the June 1 Issue of Cancer Research found that smoking affects the DNA sequence in sperm, which can lead to children inheriting permanent genetic damage from fathers who smoke.

Says Dr Rima Dada, " Smoke affects different tissue systems and it causes testicular inflammation and damage. Because of testicular damage, there is an increase in free radical production and free radicals have the tendency to damage the DNA - whether its mitrocondreal DNA or nuclear DNA."

The study, done on mice, also also suggests that damage to the DNA is related to the duration of exposure to smoke.

So what could this mean for children of smokers?

"If the DNA is damaged, if the father is infertile but the couple conceives, the child may also be born infertile. It could affect different systems because smoke is a known teratogenic. It could have affect on the muscular skeletal system and cause developmental delay and other congenital malfunctions in the baby," says Dr Rima Dada.

Earlier studies have shown that smoking can also lead to infertility among men, but a lower sperm count is clearly not the only motivation to quit smoking.