London, Nov 25 (UNI) Smoking is to blame for pregnant women undergoing needless and risky tests for Down's Syndrome, experts warned.
Chemicals in cigarettes distort the results of screening for disability. They change a woman's body chemistry and give a false reading that a baby has a high chance of being born with Down's.
This puts women at high risk of miscarriage because they then have to undergo a screening test for abnormality, the tests published in Daily mail warned.
Those who had smoked came out with a high ''false positive'' score for an abnormal baby and was required to undergo a special test known as ''amniocentesis''.
This involved a needle being inserted into the womb so that doctors could take a sample of fluid from around the baby. However, the test is risky as there is a one in 100 chance of this causing the mother to miscarry.
The findings revealed by the Royal College of Obstetricians and Gynaecologists are based on a study of 2,337 women in the first three months of normal pregnancies.
Dr Philip Steer of the British Journal of Obstetrics and Gynaecology, said the findings were further proof of the damaging effects of smoking during pregnancy.