A two-year-old boy allegedly murdered by his mother had sustained serious injuries on multiple occasions, not only in the days leading to his death, Wollongong Local Court has heard.
Evidence of the boy's injuries came on Wednesday during committal proceedings against the mother, who has pleaded not guilty to murder.
The woman, from Berkeley, cannot be named for legal reasons.
A neuropathologist at NSW Health's Department of Forensic Medicine, Dr Michael Rodriguez, detailed widespread damage to the boy's brain, some of which "had not occurred immediately before the child died" on August 3, 2012.
Dr Rodriguez said he had found signs of three brain haemorrhages he believed were several days old and two brain haemorrhages he believed were several weeks old.
"It looked to me like there were several areas of bleeding at different times," he said.
Forensic pathologist Johan Duflou described the boy's extensive injuries, including fractures to three ribs, collar bone and wrists.
There was evidence of a blunt-force injury to his stomach and a lump of tissue - "a traumatic mass" - behind his bowels.
"What I think likely was that there were injuries on a number of occasions to the abdominal [area]," Prof Duflou told the court.
Sacs in the boy's lungs were inflamed and his adrenal glands were small and lacking in lipid.
"That ... is an indication of a stress response," Prof Duflou said.
"The stress response indicates there has been a significant problem with this child for at least a number of days, and potentially for longer than that."
Prof Duflou said the boy's short stature placed him in the fifth percentile according to a standard growth chart. His weight placed him lower still on the charts.
"Certainly this child was small ... for his age," said Prof Duflou adding this could be for many reasons, including small parents, disease or malnourishment.
He attributed the cause of death to head injury.
He said not all the injuries could be explained as accidental.
"There are not injuries there that would be typical of a fall, whereas the injuries fit quite nicely as ... [being] due to infliction."
The hearing continues on Thursday before magistrate Michael Stoddart.