A 1-year-old Bronx girl was punched in the head multiple times by her mom’s teen boyfriend, leaving the baby so badly hurt she needed surgery to remove a piece of her skull, prosecutors say.

The tiny victim was only semi-conscious when cops responding to a 911 call from her mother arrived at the apartment on Union Ave. near E. 152nd St. in the South Bronx about 9:30 p.m. last Thursday, officials said.

The tot’s face and head were badly swollen, especially around her bruised left eye and she was struggling to breath, according to a criminal complaint.

Medics rushed her to Harlem Hospital, where she was in critical but stable condition. She needed to be placed on a ventilator and life support and had extensive subdural hemorrhaging on the right side of her head, according to court pap

See Full Page