Smoking During Pregnancy Could Alter Your Baby's DNA

Smoking during pregnancy may be even more dangerous than we thought, according to this new study that indicates that tobacco smoke could alter your baby's DNA.

Smoking During Pregnancy Could Alter Your Baby's DNA NAR studio/Shutterstock

A new study published in the American Journal of Human Genetics may have found the link between smoking during pregnancy and subsequent health complications in children. According to the researchers involved, this study solidifies evidence that smoking while pregnant can chemically alter a fetus's DNA, causing it to mirror DNA patterns seen in adult smokers.

Researchers have also identified the development-related genes that are affected by genes and suggest a possible explanation for the relationship between a mother's smoking during pregnancy and health issues that arise in her children. Smaller studies have also looked at this link but the current study is reportedly one of the largest of its kind—and it may be the one that helps us understand how smoking during pregnancy wreaks havoc on a fetus.

"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," co-senior author Stephanie London, an epidemiologist and physician at the National Institute of Environmental Health Sciences, said. "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."

The researchers observed over 6,000 subjects to reach their results. They pooled mothers via questionnaires asking them to identify as "sustained smokers" (meaning they smoked through pregnancy,) non smokers, or those who smoked occasionally or stopped early on in pregnancy. Researchers also collected samples from blood found in the umbilical cords of subjects after delivery.

In the newborns born to mothers who smoke occasionally, researchers found 6,073 places where their DNA was chemically modified differently than in the subjects in the "non-smoking" group. The collection of genes that were affected are related to lung and nervous system development, smoking-related cancers, birth defects including cleft lip and palate and more.

The next step? Finding out why smoking causes certain birth defects on a genetic level. The researchers will build on this study in order to determine more. "We already knew that smoking is related to cleft lip and palate, but we don't know why," London said in the study's release. "Methylation [an epigenetic shaping tool which plays a big role in gene expression] might be somehow involved in the process."