A procurator fiscal has said he is still seeking answers from NHS Greater Glasgow and Clyde about why the little boy was not seen for three months by health visitors.
The tot's decomposed remains were discovered at the home of his mother, Kimberley Hainey, on March 31, 2010, in Paisley, close to what would have been his second birthday.
During a preliminary hearing at Paisley Sheriff Court ahead of a Fatal Accident Inquiry (FAI), Procurator Fiscal Hugh Brady said he had asked for a detailed response from the director of the Community Health Partnership about health visitor checks. However, three months later, he said he was still waiting for information.
The FAI is due to start on May 12.
Solicitors representing the Community Health Partnership said a full statement should be ready within the two weeks.
It has emerged that the little boy was not seen by any health visitors between April and July 2008 because of staff reductions.
Mr Brady said he had asked if a risk assessment had been carried out to ensure that care levels were maintained despite the loss of staff.
He said: "One of the issues to be raised is that between April to July, 2009, Declan was under the care of social work and health at that point, but there was a reduction in staff at that time and he was not seen by a health visitor during that three-month period.
"There were two social workers involved. I want to ascertain if any risk assessment was done to ensure that a level of care was maintained."
Mr Brady revealed that he had been in discussions with Renfrewshire Council on what steps, if any, had been taken to introduce changes in light of the publication of the "significant case review" which was carried out and made 16 different recommendations.
In petition papers lodged with the court, it states that the exact date of Declan's death is unknown and that a post mortem failed to pinpoint cause of death.