Police did not have details on the length of her hospital stay but said the woman was treated and released from the Danbury Hospital.
There was no further information on the baby boy, who had been reported in "general good health" last week at Danbury Hospital.
"The investigation is still active and ongoing at this time," police said in a statement. It is not clear whether any arrests will be made in the case.
The woman, who has not been identified, had walked into the Danbury Police Department just after midnight Friday, May 26, after police asked for the public's assistance in locating her. Police released the 911 call reporting the discovery of the baby and photos of the clothing that he was wrapped in.
The baby was found late Sunday, May 21, in the bushes behind Zaytuna Grocery Store at 397 Main St. He was crying and cold, the 911 caller said.
When officers were searching for her, police said, "Our main concern at this time is for the mother, who may need medical attention or is a victim of a crime herself."
Click here to follow Daily Voice Danbury and receive free news updates.