PASSIVE smoking damages a woman’s fertility as much as if she were a smoker, according to research released today.

Doctors have long cautioned that smoking reduces female fertility, but the new research suggests that exposure to smoke, given off by a smouldering cigarette, is just as damaging.

The study, published in the European medical journal Human Reproduction, found that among 225 women seeking fertility treatment, those who lived with a smoker had only the same rate of success in conception as women who smoked.

That rate was half that of “smoke-free” women, said Dr Warren Foster, professor of obstetrics at McMaster University in Ontario, who led the research.

Non-smokers achieved about 48 per cent pregnancy rates per embryo transfer, smokers around 19 per cent and the side-stream smokers 20 per cent.