Exposure to second-hand smoke in the womb may affect long-term health

Children born to non-smoking mothers exposed to second-hand smoke during pregnancy have genetic mutations that may affect long-term health, according to a University of Pittsburgh Graduate School of Public Health study.

The abnormalities, which were indistinguishable from those found in newborns of mothers who were active smokers, may affect survival, birth weight and lifelong susceptibility to diseases like cancer, the study revealed.

The study confirmed previous research in which study author Stephen G. Grant, associate professor of environmental and occupational health at Pitt's Graduate School of Public Health, discovered evidence of abnormalities in the HPRT gene located on the X chromosome in cord blood from newborns of non-smokers exposed to environmental tobacco smoke.

In the current study, Dr. Grant confirmed smoke-induced mutation in another gene called glycophorin A, or GPA, that is representative of oncogenes - genes that transform normal cells into cancer cells and cause solid tumors. The GPA mutation was the same level and type in newborns of mothers who were active smokers and of non-smoking mothers exposed to tobacco smoke. Likewise, the mutations were discernable in newborns of women who had stopped smoking during their pregnancies, but who did not actively avoid second-hand smoke.

"These findings back up our previous conclusion that passive, or secondary, smoke causes permanent genetic damage in newborns that is very similar to the damage caused by active smoking," Dr. Grant said.

"By using a different assay, we were able to pick up a completely distinct yet equally important type of genetic mutation that is likely to persist throughout a child's lifetime. Pregnant women should not only stop smoking, but be aware of their exposure to tobacco smoke from other family members, work and social situations," he added.

The study was published in the online Open Pediatric Medicine Journal.