- Tuesday, 30 October 2012
Women who smoke while pregnant could cause health problems for their grandchildren - as well as their children.
Research published in journal BMC Medicine suggests that dangers can carry down generations, with a smoker's grandchildren more likely to suffer from asthma.
Experts believe this is because harm caused by smoking in pregnancy can 'switch on' bad genes, which are then passed on.
A baby's developing lungs can be affected by nicotine during pregnancy - predisposing them to childhood asthma.
This risk is well known but researchers from Harbor-UCLA Medical Center in California have investigated the risks for future generations.
They tested the effect of nicotine exposure during pregnancy on rats, looking at their pups, named F1 and second generation pups, called F2.
Research found exposure to nicotine in the womb resulted in F1 pups having reduced lung function, consistent with asthma.
But it also impaired lung function of FI's offspring F2 - even though the F1 rates were not exposed to nicotine once they were born.
A gene function associated with normal lung development was also reduced in both FI and F2 rates.
Dr Virender Rehan, who led the study, said: "When we looked at the effect of nicotine on DNA in the testes or ovaries of the rats they found that nicotine increased the level of methylation in the testes but reduced it in the ovaries.
"Nicotine also altered methylation of histone proteins in a sex-dependent manner.
"These epigenetic marks may be the mechanism behind how nicotine-induced asthma is transmitted from one generation to the next."
Asthma is the most common chronic disease of childhood and can be caused by many factors.
But he added that maternal smoking during pregnancy is an avoidable risk.
He said: "The effects of smoking during pregnancy are, it seems very long lasting.
"Stop smoking education and intervention aimed at mothers-to-be and women planning pregnancy needs to take into account the fact that nicotine itself contains dangers to their children and their children’s children."
by Claire Hayhurst - Mature Times reporter