The findings of a new, international study of 6,685 mothers and their newborns may explain why certain infant and child health problems frequently have been seen in the offspring of mothers who smoked during pregnancy, Kendall Morgan, Ph.D., wrote in the National Institutes of Health Director’s Blog.
The study, published in the American Journal of Human Genetics, “found significant differences between the epigenetic patterns of babies born to women who smoked during pregnancy and those born to nonsmokers, with many of the differences affecting genes known to play key roles in the development of the lungs, face, and nervous system,” Dr. Morgan wrote in the April 12 blog entry.
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Smaller studies show there is evidence that maternal smoking can have epigenetic effects on a fetus. The new research from 13 research cohorts reaffirms and renders this finding more statistically powerful, Dr. Morgan wrote. In the infants of women who smoked every day during pregnancy, the researchers found more than 6,000 places where chemical marks on the DNA differed from those of babies born to mothers who did not smoke during pregnancy. The researchers also observed more than 4,600 epigenetic modifications in the DNA of babies of mothers who self-identified as falling under the broad category of having engaged in “any smoking during pregnancy.”
The genes thought to cause a cleft lip and/or palate were among the others to have been epigenetically modified in the fetuses of women who smoked while pregnant. The study also suggested that thousands of the epigenetic modifications seen affected children until at least age 4 years.
Read the study in the American Journal of Human Genetics (doi: 10.1016/j.ajhg.2016.02.019).