Parents Curtis Young and Amy Wang noticed the swelling on January 29 and spoke to caregiver Parbin Kaur the next day, who admitted Jaden had fallen and hit his head on rubber matting.
Wang, a trained nurse, took Jaden to a GP who immediately referred him to Starship Hospital. Scans revealed a 6cm skull fracture and Jaden was admitted to the high dependency unit, where nurses checked his eye movements and motor functions every hour throughout the night.
"This was our worst nightmare," said Jaden's mother Amy. "We were terrified that he would die."
Father Curtis, who works at Unitec, said: "We watched Jaden every moment, of every day for his first year, making sure he was safe at all times. Yet the first day we left him under someone else's supervision, he was gravely injured."
Curtis said there had been a "catastrophic failure" by the caregiver to meet her professional responsibilities and they were meeting lawyers this week to pursue civil litigation.
He said the 24-hour delay in getting medical attention for Jaden could have been fatal.
"If the bleeding had continued, he could have experienced vomiting, unconsciousness, or even brain damage. Not knowing about this accident put Jaden at grave risk. The psychological and emotional impact of the ordeal has hit us hard as parents."
Police visited the Unitec centre on Monday, but found no evidence of criminal action.
In a letter to the parents, centre manager Marlise Shadbolt said: "It is inconceivable that Parbin forgot to complete an accident form at the time and then compounded this by failing to tell Curtis about the incident on Tuesday night."
The parents have noticed Jaden's balance has been affected since the head blow. However, they won't know whether he has any lasting effects for some time because there is no concussion test for toddlers.
The centre's chairman, Tony Carr, said the centre was investigating and wanted to express their sympathies to Curtis and Amy.
"I have children at the centre and it's our priority to make it a safe place for children."
Meanwhile, the caregiver at the centre of the claims, Parbin Kaur, continues to work on.
Young and Wang call Jaden their "miracle baby" after spending three years trying to get pregnant, eventually succeeding through IVF treatment. Jaden was born four weeks premature after Amy suffered heavy bleeding during the latter stages of her pregnancy and spent four weeks in hospital.
Now they are afraid to let him out of their sight. Wang has been forced to take time away from her job as a school dental assistant to care for Jaden.
Young says the family may be forced to take out a second mortgage. "Through no fault of our own, Amy could be out of a job."
ACC figures indicate more than 1000 children aged up to 4 are hurt in accidents at early education centres every year.
There were 1035 claims in 2010, 1189 in 2011 and 1328 in 2012.
One early education teacher, who declined to be named, said there was chronic under-reporting of injuries.
"There are definitely centres who don't have a clue. They don't know the procedure."
The Early Childhood Council believes that young learning centres face a bewildering array of legislation to comply with.
Chief executive Peter Reynolds said it was a highly regulated environment that could lead to misinterpretation of the rules and people not understanding what was required.
