The accused, who works as a tailor, was arrested yesterday, they said.
The incident happened Sunday evening when the accused took the girl to his home. Since the victim's father, who runs a tea stall in the area, knows the accused, he often lets Yadav play with the girl.
A couple of hours later, Yadav left the baby at the entrance of her house where her family found her bleeding from her private parts.
They rushed her to a hospital nearby but she was in a critical condition and was referred to the LNJP hospital where she is undergoing treatment and is stated to be stable, police said.