LONDON: Moms-to-be, please note -- if you don't want to risk miscarriage, just quit smoking.

A team of international researchers has carried out a study and found that chemicals in cigarettes change a pregnant woman's body chemistry and distort the results of screening for disability in the foetus, the 'Daily Mail' reported on Saturday.

This puts women at high risk of miscarriage as they then have to undergo a further screening test for abnormality, according to the researchers.

According to Imperial College-based Prof Philip Steer, the Editor-in-Chief of the 'British Journal of Obstetrics and Gynaecology' which has published the study, "The findings were further proof of damaging effects of smoking during pregnancy.

"Babies of mothers who smoke during pregnancy are small for gestational age and tend also to deliver earlier. This research indicates smoking may also cause over-estimation of the risk of Down's (Syndrome), thus exposing the mother to a higher risk of an unnecessary amniocentesis."

In fact, the researchers came to the conclusion after analysing the effects of smoking on 2,337 women in the first three months of normal pregnancies. Those who had smoked just a few cigarettes a day came out with a high "false positive" score for an abnormal baby.