The girl was admitted to the hospital on September 20 in an advanced stage of pregnancy, with severe complications. She gave birth to the baby boy on Monday, they said.
It is though not clear who sexually assaulted the girl.
Though police tried to register a complaint on the basis of information given by SAT Hospital authorities yesterday, her parents were not willing to do so.
The teenager, an eighth standard student, is from Kottarakkara in Kollam district.