A coroner is asking social services to clarify the advice offered to families after two infants died alongside their parents in bed.
Cleethorpes coroner Stuart Atkinson is conducting inquests on Wednesday into the deaths of Alisa Marie Warton, five months, and new-born McKenzie Heafey.
The so-called "overlaying" deaths are among four such cases being heard by the same coroner in the next few weeks.
North and NE Lincolnshire social services have been invited to attend.
Mr Atkinson wants to know what information, in the form of either booklets, leaflets or direct advice, is available to the parents of new-born children.
Sheffield pathologist Dr Marta Cohen is also due to attend the inquests after recently dealing with six infant overlay deaths.
Seven years ago the Bradford Coroner Roger Whittaker wrote to the Department of Health requesting specific guidance for parents after a child died while sleeping in the same single hospital bed as her parents.