Could a woman's health habits during pregnancy give her baby food allergies?

Allergies can start to develop before babies are born and may be influenced by their mother's behaviour while she is pregnant, new research shows.

For the first time ever the study by the Murdoch Childrens Research Institute in Melbourne showed key differences in the blood samples of babies who have food allergies and babies who don't, which could provide vital clues to identifying the cause of allergies, The Daily Mail reported.

Report author Dr David Martino said when he compared the blood samples of 12-month-old babies he found the samples from infants with allergies had molecular pathways that operated differently.

'We actually looked at the molecular switches that control how genes are expressed and we found that there was an association with food allergy and disruption in some of these switches,' Dr Martino told Daily Mail Australia.

The researchers then examined blood samples taken from the allergic children at birth, and found that the majority of the children showed these molecular differences were present when they were born.

'This means we think that some of the predisposition to developing food allergies may be already programmed into the developing child as early as pregnancy,' Dr Martino said.

He added that this finding would help researchers investigate what mothers are exposed to during pregnancy, and how certain factors can modify the way their babies' genes behave.

Report co-author Katie Allen told The Today Show: 'We want to look to see whether there are some factors that occur in the baby in utero that we can modify simply before the baby is born.

'What we'll be looking at are things like diet and weight and smoking to see if we modify those whether that changes the control of the genes and therefore the risk of the baby developing food allergy.'

The study looked at 24 children in total and will now be conducted on a wider scale with 5300 babies.

Most of the allergic children studied were allergic to egg, and some were allergic to peanuts.

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