The woman has been staying with her in-laws at Puduvalasai village in this district while her husband worked in the Middle-East for the past two-and-a-half years.
Her second baby was born on March 20. She slit the baby's throat and buried it in the backyard of her house.
In the meanwhile, people in the neighbourhood enquired about her about the child and one of the neighbours informed police suspecting that she could have committed infanticide.
Police after recovering the body, registered a case of infanticide and trying to erase the evidence and arrested her, police said.