Cigarette Smoke to Prevent Pregnancy Complication

A potentially poisonous gas found in cigarette smoke could prevent pre-eclampsia.

Carbon monoxide, a potentially poisonous and even carcinogenic gas found in cigarette smoke and automobile emissions, may prevent the premature death of cells in placenta. This way, carbon monoxide may help treat pre-eclampsia, a common pregnancy compication.

Pre-eclampsia is present when hypertension arises in pregnancy in association with significant protein in the urine.

Smokers, who inhale relatively high levels of carbon monoxide, have a lower-than-average risk of pre-eclampsia, note Dr. Graeme M. Smith and associates at Queens University Hospital in Kingston, Ontario.

Cells in placental tissue exposed to carbon monoxide had a 60-percent lower death rate than cells in unexposed tissue, according to the report in The American Journal of Pathology.

However, this doesn't mean that pregnant woman should start smoking or inhaling second-hand smoke. Carbon monoxide as a treatment for pre-eclampsia is many years away, scientists report. Before any treatment becomes a reality, doctors must determine what levels of this dangerous chemical are safe for the fetus. They also need to find a safe way to deliver carbon monoxide to the mother.

"I suspect we're three or four years away from pregnant animal studies, to get an idea of 'safe' carbon monoxide levels from the fetal point of view," Dr. Smith told Reuters Health.

"That would mean a year or two after that before we'd be looking at human studies. The ideal would likely be to maintain carbon monoxide levels comparable to a moderate (say one pack per day) smoker without all the bad stuff in cigarette smoke."