Wow, this is a big deal. Research published in the American Journal of Human Genetics shows that if pregnant women smoke, it can alter the DNA of their unborn children.

From an article by Medical Daily, reprinted by Raw Story. I’ll let it speak for itself:

“I think women already know that they shouldn’t smoke,”co-senior author Stephanie London told Medical Daily, noting that the new findings solidify evidence that smoking while pregnant does impact the fetus. “So it’s not like this ‘oh maybe it has some effect’ … we can physically see this evidence.”

The study, led by an international team of researchers, found that cigarette use during pregnancy resulted in some modifications in the fetus’ DNA. What’s more, these changes mirrored those seen in adult smokers.

“What surprised me most about the study is you see the same changes in a newborn from the mother smoking during pregnancy as you’d see  in an adult from their own smoking. Many of the same changes,” London said.

Researchers combed through data from 13 studies involving 6,685 newborns and their mothers from around the world. The mothers fell into one of the three categories: “sustained smokers” who continued to smoke daily throughout their pregnancies, and “non-smokers,” or those who smoked occasionally during their pregnancies. To examine the newborns’ DNA, researchers collected samples mainly from the blood in the umbilical cord after delivery.

The data showed that sustained smokers gave birth to children who had their DNA chemically modified in 6,073 places. Researchers said half of these locations were tied to specific genes related to the development of the lung and nervous system, smoking-related cancers, and birth defects such as having a cleft lip or palate. This means the offspring of mothers who smoked during pregnancy may be more likely to suffer health complications during their lifetime because smoking affects organ systems and developmental processes in newborns, London said.

“I find it kind of amazing when we see these epigenetic signals in newborns, from in utero exposure, lighting up the same genes as an adult’s own cigarette smoking. There’s a lot of overlap,” said London, an epidemiologist and physician at the National Institute of Environmental Health Sciences (NIEHS). “This is a blood-borne exposure to smoking — the fetus isn’t breathing it, but many of the same things are going to be passing through the placenta.”

I read some of the comments on a couple of stories about this, with some smokers expressing skepticism about the results. Really? In this day and age? Smokers still in denial.

For me, the most shocking statement in this story wasn’t that smoking is thought to cause DNA damage in fetuses … it’s that in this day and age 12.3 percent of expectant mothers smoke. Holy Christ on a crutch .. that many pregnant women still smoke today? That sincerely blew me away.

Here’s the truth … it’s been known for some time that the chemicals in smoking, one of which is a radioactive isotope called Polonium-210,  tears apart the DNA in smokers’ lung cells, which is the No. 1 reason why some smokers get lung cancer.  So, why is it such a big leap for this people to believe some fairly extensive research showing potential DNA damage to fetuses? Especially when it’s been long known that smoking by pregnant women causes low birth rate and increases the risk of SIDS.

It’s certainly a sea change from old attitudes about pregnancy and smoking. Believe it or not, there was really, actually a real honest to goodness cigarette ad in the 1950s featuring a pregnant woman buying tobacco. No, not this fake ad from Bioshock Buried at Sea. A real ad. I included both. See if you can tell which one is fake and which one is for real.