Helping the youngest
Telling a child the truth is of utmost importance in everyday life situation; when one of his/her beloved ones (parent, grandparent, uncle/aunt..) is admitted in hospital this behaviour gains more and more relevance. An appropriate language and few simple words could be enough; no need for details and deeper explanations.
A child must understand that feelings like sadness, fear and anger are normal in settings like this; the adult must reassure the youngest and legitimate his/her own feelings also in the hardest situations such as the moment of hospitalization and everytime new events happen.
A child needs to feel your support because reassurance begins with staying next to him. A qualified expert, such as a psycologist, could help the family in this setting; whoever will help the baby, he/she would choose his/her closest ones.