The 22-year-old woman told police she had been hiding the pregnancy because she was afraid of a scolding from her parents and couldn't afford an abortion, police said.
On Saturday she gave birth to a baby boy in a squat toilet at her apartment building and said the baby slipped into the sewer before she could grab him, Shanghai Daily reported Wednesday.
She told police she notified the landlord and firefighters were called to cut the pipe. The baby was taken to a hospital where he was freed. The child had severe bruising but was listed in stable condition.
The woman, whose name wasn't reported, was on the scene of the rescue operation and expressed worry, though police said they weren't suspicious that she was the mother until they interviewed her Monday and found blood-stained tissues in her apartment, China Radio International reported.
Police said they had been treating the case as an attempted homicide but now that the mother has come forward, it isn't clear if she will face charges. Officials haven't determined if she legitimately attempted to save her baby or intentionally dumped him, the Daily said.