The Southeastern Pennsylvania Transportation Authority said the pregnant woman was riding the Broad Street Line subway train Tuesday afternoon when she gave birth, WCAU-TV, Philadelphia, reported Wednesday.
The woman got off the train at Philadelphia's Olney Station with the umbilical cord still attached to the newborn.
SEPTA police officer Loyd Rodgers, who swaddled the newborn in a blanket and called for medical assistance, told KYW-TV, Philadelphia, other train riders took photos and shouted "congratulations" to the new mother.
"It was a celebration, a real celebration," Rodgers said.
SEPTA officials said the mother and child were taken to a hospital where they were said to be doing well.