Secondhand Smoke Risk Seen in Pregnancy

Pregnant women exposed to other people’s cigarette smoke might be raising their fetuses’ risk of developing cancer in childhood.

A study found that babies born to such mothers showed higher rates of a kind of genetic mutation in blood cells. This kind of mutation is caused by a certain enzyme and is often found in childhood leukemia and lymphoma.

Experts said it is the first time scientists have linked secondhand smoke to genetic mutations in a fetus. Prior research found elevated mutation rates in fetuses from women who themselves smoked during pregnancy.

The study doesn’t show a direct link to cancer. In fact, the specific gene mutations it monitored are harmless because they occurred in a gene unrelated to cancer.

The findings only suggest that the mutation-making enzyme might become more active, raising the risk of hazardous mutations in cancer-related genes.

The study couldn’t define how big a risk secondhand smoke might pose, but it’s rare for children to get leukemia or lymphoma. About 3,000 new cases, mostly leukemia, are expected in the U.S. this year in children 14 and younger.

The work was presented in the October issue of the journal Nature Medicine.