The woman, who have no children, had yesterday approached Keerthika, who gave birth to a girl a few days ago at the Tirumarugal Primary Health Center posing as a health worker and taken the kid in the pretext of administering immunisation drops.
Since the woman did not return back, Keerthika raised an alarm.
The woman was arrested after examining the CCTV footage in the hospital, police said, adding, the child was handed over to her mother.