BABIES born to women who smoked while pregnant could be exposed to different health problems as adults depending on their sex, according to new research.

Scientists have discovered that the livers of foetuses start to process chemicals transferred from blood from their mother's placenta at the end of the first trimester.

And new research shows that by-products of cigarettes cause changes in the amounts of important proteins in the livers of the developing baby at the age of just 10 weeks.

Researchers from the universities of Aberdeen, Glasgow and Edinburgh found that some of these changes were sex-specific and could manifest themselves in different ways in later life.

Male babies are believed to be more likely to develop liver cirrhosis and cancer compared to females, who are more at risk of conditions such as obesity and diabetes when they are adults.

Yesterday Aberdeen University Professor Paul Fowler, who was involved in the research, said: "Even in foetal life organs may be aware of which sex they are.

"In male foetuses there is a big pulse of testosterone made by the testes between 10 and 14 weeks of gestation. And a lot of organs have a particular receptor for testosterone and will respond to that testosterone in a way that will make them more male.

"What we are seeing here in our study is that this has implications right down to how the liver is responding to the challenge of the mother smoking."

Professor Fowler said at least 4,800 chemicals from cigarette smoke get into the foetus when a pregnant woman smokes and the first place they go to in the foetus is the liver.

"We found that the changes in the male foetuses are linked with liver cirrhosis while those in the female are linked with disorders of glucose metabolism," he said.

"The implications are that the foetal livers are already being programmed towards metabolic syndrome, i.e. obesity, cardiovascular disease and liver disease. It is likely that these changes might make these individuals more susceptible to these diseases in adulthood."

Scientists at the universities now believe that smoking alters proteins in the liver of foetuses which reduces how well they work.

Tests were carried out on the livers of second trimester foetuses donated by mothers who had non-medical pregnancy terminations since 2004.

Professor Fowler said the researchers used sophisticated online software to determine the disease or toxicological pathways on altered proteins.

He said: "We saw that in males in particular, some of the pathways that were changed were changed in the direction that would suggest that the individual was becoming more prone to cancer."

The links between maternal cigarette smoking and reduced health in offspring are well known.

Previous studies have suggested that smoke exposure in the womb has been associated with different health outcomes for boys and girls - with boys at a higher risk of conduct disorder while girls are more prone to drug dependence and increased body weight.

Professor Peter O'Shaughnessy, from the University of Glasgow, says: "The different responses between male and female livers suggest that sex-specific health outcomes might be related to important different molecular responses in the womb, indicating that sex differences in foetal liver responses to maternal smoking may contribute to subsequent disease predisposition."

It is hoped that this latest research could be taken forward to help counteract any health issues that babies exposed to smoke in the womb may develop.