By linking data from the Mater-University of Queensland Study of Pregnancy - Australia's largest longitudinal study tracking mothers and their children - with reports of maltreatment recorded by the Department of Child Safety, Dr Strathearn found mothers who breastfed were less likely to neglect their children.

"Mothers who didn't breastfeed were almost four times more likely to be reported for maternal neglect than mothers who breastfed for four of more months," he said.

"For mothers who breastfed for less than four months, the risk was about 2.3 times."

In what is believed to be the first population study to provide statistics on the rate of child abuse in Australia, seven percent of children were identified as victims of maltreatment.

Of the 7223 children in the birth cohort, 512 were confirmed cases of maltreatment, with the mother identified as the perpetrator 60 percent of the time.

While it was impossible to conduct a randomised trial, Dr Strathearn said breastfeeding offered a realistic explanation.

"The difficulty with this research subject is that you can't randomly assign a woman to breastfeed her baby and another one not to, so there's always potential for bias," he said.

"But, these results make sense biologically because breastfeeding is associated with oxytocin release, and we know from animal studies that oxytocin is produced in the brain and helps activate areas of the brain that are involved in maternal care and behaviour.

"There are some other functional MRI studies which show how an intranasal dose of oxytocin actually affects how the brain responds to stressful or anxiety-provoking situations and increases trust in a dyadic exchange between two people.

"There are all these results from placebo-controlled trials which provide evidence that oxytocin does result in changes in social behaviour, and so I think this study fits in nicely with that other research."

While the biological function of oxytocin offered a logical explanation, Dr Strathearn said the physical bond created between the mother and baby during breastfeeding could also be a contributing factor.

"I think for a long time we've thought anyone can feed the baby as long as it's expressed breast milk," he said.

"But this is saying well hold on, it's not just the milk, it's that relationship that's important.

"Breastfeeding may simply promote that interpersonal bond between a mother and her baby - the physical touch, the holding, the eye-to-eye contact.

"It ensures that physical touch occurs in an attuned way, but I would imagine a similar result for any mother who has that same one-on-one contact while they're feeding on a regular basis."

The study will be published in the February issue of medical journal, Pediatrics. http://pediatrics.aappublications.org/

Provided by University of Queensland