Researchers at Edinburgh University have found that women who suffer from stress during pregnancy are more likely to pass on life-threatening diseases to the unborn child and even future generations.
Dr Mandy Drake, Medical Research Council fellow at Edinburgh University and a consultant paediatrician discovered that increased levels of stress hormone in the mother are passed to the foetus and can cause heart disease and diabetes.
However, the most remarkable suggestion from the groundbreaking research is that the hormones can 'flick' a genetic switch that predisposes subsequent generations to the same illnesses.
For the study, Drake used rats and mice in her experiments, giving them artificial stress hormones and examining the results.
She examined the effect of cortisol - the stress hormone released as part of the body's 'fight or flight' response - on the foetus.
A mother who is seriously stressed will produce higher levels of cortisol, the researchers found.
Drake found that if a mother is stressed during pregnancy this can cause health problems such as low birth rate, high blood pressure and diabetes in not just her own babies but her grandchildren as well.
It is thought that high levels of cortisol cross the placenta and alter the way genes function in the developing child, which can in turn affect future offspring.
"If this happens in pregnancy the offspring may be more at risk of low birth weight and developing high blood pressure and heart disease," the Scotsman quoted Drake, as saying.
"We are now starting to recognise that this is also being passed down to the next generation. We are seeing the same problems in the grandchildren," she added.