Police said the mother, 19-year-old Marlen Ochoa-Lopez, was lured to a home where she was killed and had her baby taken from her womb on April 23.
The baby, Yovanny, had been hospitalized in intensive care before dying Friday.
In a statement, the family spokesperson said, "It is with great sadness that we inform you of the passing of baby Yovanny Jadiel Lopez. He passed away this morning Friday June 14, 2019 from his severe brain injury. Please keep his family in your thoughts & prayers as they go through this difficult time."
Three people have been charged in Ochoa-Lopez's death.
Prosecutors said Clarisa Figueroa lured the 19-year-old to her home with the promise of free baby clothes, then allegedly killed the young woman with the help of her daughter Desiree.
Police said Figueroa removed the child from the womb and then showed up to the hospital with the infant.
According to the Department of Children and Family Services, the hospital contacted the agency on May 9, more than two weeks after Figueroa first checked into the hospital.
Three weeks after Marlen's disappearance, authorities said her remains were found in the Figueroa's home where police said she was murdered.
Clarisa Figueroa and Desiree Figueroa have been charged with first-degree murder.
Clarisa's boyfriend, Piotr Bobak, has been charged with concealing a homicide.