Sharon's Baby (1975)

Something is wrong with Gino and Lucy Carlesi's newborn baby: he seems to possess an otherworldly, almost-demonic strength. As a string of bizarre incidents and a wet-nurse's strange death send shivers down the spine, the worried parents turn to Lucy's obstetrician, the cryptic Dr. Finch, for help, only to realize that the baby's abnormal energy grows stronger by the minute. It's up to Gino's nun sister Albana to take over and try to expel the evil force that resides in the seemingly-innocent child. What is the secret of the monster?