Bassinets and bedside sleepers which are opened on one side and face your bed have weight restrictions. Some have weight limits as light as 10 pounds, which may barely last a month depending on your baby's size at birth, but the majority can handle up to a 20-pound infant. The weight restriction for your bassinet may be found in the instruction manual or on the manufacturer's website. If you can't locate the weight restriction, err on the side of caution and put your baby in a crib after they reach 15 pounds.