The incident happened early morning yesterday, police said.
Lahu Dhndre, the accused, hails from Sarola Kherdi village in the tehsil.
He married Lata, daughter of Laxman Gaikwad, resident of Nandri, in May last year.
Lata had returned to her parents because of alleged torture at the in-laws' house.
On Wednesday early morning, Lahu allegedly sneaked into his in-laws' house at Nandri, lifted the sleeping baby, and slit her and threw the body outside.
Police arrested him on suspicion. Probe is on.