DOCTORS are being trained in how to deliver super-sized babies as the country's obesity epidemic worsens.

The large newborns - most born to obese and overweight mothers - are so big their shoulders are becoming stuck during labour.

In extreme cases doctors have to break their collarbones to free them and save their lives.

One in four Australian women is obese when they become pregnant, increasing health risks for both mother and baby.



In Melbourne, Royal Women's Hospital maternity services director Assoc Prof Louise Kornman said broken bones occurred in busy hospitals a couple of times a year.



"I would imagine this will gradually increase as the size of mothers having babies increases," she told the Herald Sun.

But doctors in Queensland say the shock procedure is carried out on up to 1000 infants across the state.

Brisbane obstetrician Dr Gino Pecoraro, president of the Australian Medical Association Queensland, said an increasing number of cases meant junior doctors now took part in regular mock-up trials.



He said obese and overweight women were more likely to give birth to babies over 4kg, with a greater risk of the babies becoming stuck in a condition known as shoulder dystocia.

"This is far more common in the last five years because of the obesity epidemic," he told the Courier-Mail.

"It is an emergency situation where the baby's head comes out but the shoulders get stuck, compressing the umbilical cord which delivers oxygen.

"We push down on the clavicle with our thumb and finger to free the baby."

It comes as Queensland is in the grip of an obesity epidemic, with almost half of expectant mothers now overweight or obese, and one in four classed as obese.

It is estimated shoulder dystocia affects up to 1.5 per cent of all babies with a birth weight of 2.5kg (5 pounds 8 ounces).



This incidence increases to around 10 per cent in babies weighing more than 4kg (8 pounds 13 ounces) and to 22.6 per cent in babies bigger than 4.5kg (9 pounds 14 ounces.)

Of the 66,097 babies born in Queensland last year, 12 per cent weighed over 4kg and it is estimated around 960 suffered shoulder dystocia at birth.

After delivery the injured newborn is unable to move its arm until the bone heals, which can take weeks.

Dr Pecoraro said despite the risks it was better to let an obese woman try and labour naturally rather than carrying out an elective caesarean.

Meanwhile, thousands of pregnant women are refusing to give up smoking despite an increasing number of Queenslanders abandoning cigarettes.

New figures released today in The Health of Queenslanders report shows the number of Queenslanders smoking has fallen by 6.6 per cent, from 22.1 per cent in 2001 to 15.5 per cent in 2010.

But chief health officer Dr Jeannette Young said one in five pregnant women who are past 20 weeks gestation are still smoking.