PREGNANT SMOKERS TRANSMIT TOXINS

BOSTON -- Women who smoke cigarettes during pregnancy transmit one of
the most powerful carcinogens in tobacco smoke straight to the blood
of their unborn babies, scientists reported here yesterday.

Until now, public health authorities believed that nicotine and carbon
monoxide were the two most dangerous substances passed from the blood
of smoking mothers through the placenta into the blood of a developing
fetus.

Carbon monoxide decreases the amount of oxygen circulating inside the
fetus' body. Nicotine, which is highly addictive, has its own adverse
effects. Both substances got much of the blame for rouge's gallery of
harmful effects linked known to occur in babies born to smoking mothers.

"This represents an unacceptable new risk to the fetus," Dr. Stephen
S. Hecht said in an interview. "Women should make every effort to not
to smoke during pregnancy, or any other time, for that matter."

Dr. Hecht reported the first direct chemical evidence that a powerful
tobacco carcinogen, NNK, is transmitted to the developing fetus when a
woman smokes cigarettes. He announced the finding at the 216th
national meeting of the American Chemical Society (ACS), being held
here this week.

With 155,000 members, the ACS is the world's largest scientific
organization. About 14,000 members are gathering here to present and
hear 6,700 reports on new advances in scientific fields -- ranging
from astronomy to zoology that involve chemistry.

In addition to holding national meetings, the ACS publishes most of
the world's top chemistry journals, sets standards for chemical names
and education, and engages in other activities.

Smoking is surprisingly common among pregnant women, Dr. Hecht
noted.

Tobacco smoke contains more than 2,500 chemical compounds, including
about 40 carcinogens, substances that cause cancer.

Dr. Hecht and his associates detected NNK and related compounds in
urine samples collected from newborn infants whose mothers smoked
during pregnancy. No NNK was found in urine of infants born to
non-smoking mothers.

Since the carcinogen is found only in tobacco smoke, there was no
other possible way, aside from cigarette smoking, in which it could
have gotten into the infants' bodies, Dr. Hecht said.

Researchers do not know whether NNK, like nicotine, also is passed to
infants in the breast milk of smoking mothers who nurse, Dr. Hecht
said.

Women who smoke have a higher risk of complications during pregnancy,
low birthweight babies, stillbirths, and more babies who die during
the first month of infancy, according to the American Cancer Society.

The society said studies also link smoking during pregnancy with
long-term effects on a child. At age 7, for instance, children whose
mothers smoked heavily during pregnancy were shorter in stature and
had lower reading ability than other children.

Dr. Hecht said the precise risks to unborn infants from NNK are not
yet clear.

One major concern involves the possibility that infants exposed to
such a carcinogen before birth may have an increased of cancer as
adults, he said.

The cancer society says that children exposed to 10 or more cigarettes
during pregnancy have a 50 per cent higher risk of cancer.

Checked-by: Patrick Henry