Health authorities are investigating a cluster of birth defects affecting an alarming number of babies born in a small northern New South Wales community.

Gastroschisis is a condition where a baby's intestines and organs grow outside the body through a hole in the abdominal wall.

The global incidence of gastroschisis is one in 5,000, but data from the Australian Bureau of Statistics puts the incidence for NSW's Northern Rivers region at one in 950 births.

In the past three years there have been at least seven babies born with the defect around the community of Wadeville.

NSW Health declined to be interviewed by ABC1's 7.30, but it is currently investigating a possible gastroschisis cluster in the Northern Rivers and an expert panel is expected to meet this month.

Wadeville resident Angela Summers is one mum who has first-hand knowledge of the condition. Her second child, Indi Black Summers, was born with Gastroschisis.

"I felt really alone being at a hospital no one knew nothing. It was hard," she said.

But a small article in the local newspaper about Indi set off a staggering chain of events.

Parents Jacqui McSkimming and her partner Matt Ostilla saw the article after their son Olive was also born with Gastroschisis.

The couple from Barkers Vale, just five minutes drive from Wadeville, discovered their son had the condition 36 hours before he was born.

"It was just a chaos, a mess having so much stuff hanging outside of him; actually I don't know how the surgeon held him up without it all falling on the ground," Mr Ostilla said.

Until Ms Summers and Ms McSkimming met they had no idea how similar their experiences were.

Nor did they realise there were many more families from the area whose babies had been born with the same birth defect in the past three years.

"Six other babies with gastroschisis all at once, all in the Mater Mothers," Ms Summers said.

Kellie Thomas and her partner Troy Rose from Goonellabah were one of the six families. Their third child Mia was born with an acute case of Gastroschisis.

"It was hard, it was really hard to sit there and watch Mia, it was hard to watch her vomiting every two hours," Ms Thomas said.

"Her bowel turned right around and pushed her appendix up on the other side. It was horrible just watching her and not being able to do anything to help her."

Risk factors

Ms Thomas says she did not have any of the known risk factors associated with having a baby born with Gastroschisis, such as amphetamine and cannabis use, drinking alcohol, smoking cigarettes, or being under the age of 20.

"I was wondering why. Why it was happening? Because we were told there was no reasons for this and then all of a sudden there's all these babies within a 35 kilometre range with the same problem," she said.

"And we really would like to know what has caused this and if someone's to blame, well we need to know."

Elowyn Paitson also had no risk factors. But her daughter Obelia, now two-years old, was born with an extreme case of Gastroschisis.

Up to 10 per cent of children born with the condition do not survive and Obelia's doctor feared the worst.

"He was really not optimistic about her chances of surviving the first surgery. The actual hole was only about two centimetres but all of her large intestine and most of her small intestine, part of her liver and all of her reproductive organs were on the outside," Ms Paitson said.

"It's definitely really concerning. We don't live in a highly populous area."

Brisbane paediatrician Dr Tim Donovan has also been monitoring the rising rate of gastroschisis in Queensland.

"It's essentially risen by a factor of 500 per cent over the last decade," he said.

"It is a large increase and that is why there is interest in this particular anomaly."

Pesticide link

In 2010, the Environmental Defenders Office and the National Toxins Network investigated which pesticides and herbicides were being sprayed by farmers in the Northern Rivers.

"On that list it's incredible to find that there are seven pesticides that are actually banned in the European Union," Jo Immig, an environmental scientist and spokesperson for the National Toxins Network said.

One of those chemicals is Atrazine, a herbicide widely used in Australia to control weeds in a variety of crops.

In 2010, researchers at the University of Washington released a landmark study analysing almost 20 years of medical and agricultural data for Eastern Washington.

It linked the rising rate of gastroschisis to exposure to Atrazine-contaminated waters, particularly for women who conceived in spring - the peak spraying time.

Another 2010 study from the University of California found one in 10 male frogs exposed to Atrazine turned into females, while 75 per cent were rendered sterile.

Studies done by the manufacturer of Atrazine did not come to the same conclusions.

The Australian Pesticides and Veterinary Medicines Authority (APVMA) is the regulator of pesticides.

"The APVMA has reviewed in detail scientific studies that suggest possible links between Atrazine and gastroschisis and Atrazine and Hermaphrodism in frogs. While the studies are interesting, they do not satisfy internationally accepted standards of scientific rigour relevance and reliability, which regulators rely upon to make decisions," the APVMA said in a statement.

Dr Donovan says there may be no link between gastroschisis and pesticides and herbicides used in the Northern Rivers

"In gastroschisis if there was a pesticide link then the link would probably include some difference between rural mothers with a rural postcode and rural addresses versus metropolitan mothers," he said.

"And there is no clear answer but the risk seems to be higher in metropolitan mothers in Europe particularly, in the United Kingdom particularly than it is in regional mothers.

"That doesn't mean that pesticides can't be part of multiple causes but it certainly makes it less likely that it's the only cause."