Bounty

Baby boys exposed to tobacco while in their mothers' womb risk developing fertility problems in later life, according to a new study.

Researchers found that male embryos in women who smoke during early pregnancy develop significantly fewer immature reproductive cells than foetuses in non-smoking mothers.

A team of scientists led by Professor Claus Andersen, from the University Hospital of Copenhagen in Denmark, examined the number of germ cells - the cells that develop into sperms in males and eggs in females - in embryos obtained through legal termination of pregnancies between 37 and 68 days.

They studied 24 embryos and found that those from women who smoked had less than half the number of germ cells in those from non-smokers. Embryos from smoking mothers also had a third fewer non-reproductive somatic cells.

Previous research on female foetuses had shown similar results, the team said in their paper published in the journal Human Reproduction.

Meanwhile, a second study found reduced levels of a protein, which plays an important role in the development of sperm, in men who smoke.

The new work sheds further light on the links between smoking and infertility, and reinforces public health advice urging couples to quit the habit before attempting to conceive.

Copyright Press Association 2010