0852 GMT July 23, 2019
Their findings add significant weight to existing knowledge of the dangers of smoking while pregnant and show that risks may be even greater than previously thought, Physorg said.
The study, by researchers from the universities of Aberdeen, Edinburgh and Glasgow, together with Professor Kevin Sinclair from the University of Nottingham, showed that maternal smoking leads to crucial changes in chemical tags known as 'epigenetic marks' which are normally attached to DNA. These epigenetic marks, known as DNA methylation, can affect how genes function. The researchers were able to show for the first time that such changes are present in the livers of fetuses of between 12 and 20 weeks gestation.
Professor Paul Fowler, from the University of Aberdeen who led the Medical Research Council funded project, said, "We identified changes in DNA methylation of genes which are crucial for the growth and development of a baby when a mother smokes.
"These findings strengthen and extend previous studies by showing that such changes are detectable during second trimester development. This is a clear demonstration that maternal smoking early in pregnancy can program incorrect development of the liver, which is a vital organ both in the fetus and, of course, after birth.
"This is significant because a worryingly high number of women will continue to smoke during pregnancy and the observed effects of DNA methylation may become amplified with ongoing exposure to cigarette smoke in the womb."
Despite current health warnings, it is estimated that the prevalence of smoking during pregnancy remains high. In developed countries up to 25 percent of pregnant women smoke and fewer than 4 percent stop smoking while pregnant.
These early changes in DNA methylation may mean the baby is more susceptible to a range of diseases in the future.