It's dangerous to have a baby sleeping in a pram because even tiny babies can wiggle and fall out or get caught in straps but AFAIK the removable bassinets that some prams have are ok. Just so long as it has no straps that bubs can get tangled in and a 'wall' so they can't slip out.

Another option is a hammock - you can move them around the house easily and they're pretty small and you get more use out of them than a bassinette.