DNA methylation, gene expression and poor birth outcomes
The research team put together seven independent cohort studies of the PACE consortium, involving a total of 1,700 mother-infant pairs from Australia, France, Spain, Canada and the United States. Their analysis revealed over 200 methylation sites that were associated with both maternal smoking and pre-term birth or lower weight at birth. These methylation sites were in or near genes involved in multiple placental functions, including regulation of inflammatory or growth signals. They also saw that this response to tobacco smoke was unique to the placenta—such DNA methylation changes were not observed in cord blood DNA.
“The genes and pathways identified in this study can help us decipher the mechanisms by which tobacco smoke affects placental function and foetal growth,” says Bustamante.