The baby boy was born on November 30, bringing the total number of Australian children in the al-Hawl camp to 47, most of whom are aged under five.

"It's hard to imagine a worse place for a child to be born than inside these camps," Save the Children spokesman Mat Tinkler said on Wednesday.

"The arrival of another brutal Syrian winter brings the added threat of snow storms, sleet and icy conditions."

The boy's mother, from western Sydney, was pregnant when she entered the camp.

His father is missing.

In the past year, hundreds of children have died, either inside the camps or on their way to them from conflict zones.

"This baby has the odds stacked against him from the very first day of his life," Mr Tinkler said.

"He is one of thousands of children forced to live without running water, proper healthcare facilities and where food supply is highly uncertain."

The baby boy and his mother are said to be in reasonable health.

"However, this child's life - and the lives of the more than 40 other Australian children trapped in this camp - remain at risk as long as they remain in such a dire environment," Mr Tinkler said.

"A number of these children are already suffering pneumonia and other treatable illnesses, a situation which will only be exacerbated with the onset of winter."

Save the Children has repeated calls for the Morrison government to evacuate Australians from the camp.

The government has repeatedly rejected calls to repatriate the women and children, arguing it would place Australian lives at risk.

Australian Associated Press