The child was close to death after being discovered wrapped in towels in a trash sack. Police said the mother had disposed of the newborn shortly after she gave birth to it on Friday.
A newborn baby girl was rescued from a garbage bag on Monday in the German town of Kierspe in the western state of North Rhine-Westphalia.
Police discovered the child behind a house after officers heard crying from a bush, public prosecutor Michael Burggräf said.
The newborn, whose body temperature was a dangerously low 31 degrees, was struggling for air after some three hours in the knotted sack.
Burggräf said the baby has since recovered and was receiving medical care at a nearby clinic.
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Police said a 31-year-old woman had told them that she had placed the girl in the sack shortly after giving birth to the child on Friday.
When her partner saw that she was bleeding, he allegedly suspected that she was suffering from an infection and called an ambulance despite the woman's wish to stay at home.
After she arrived at the hospital, doctors discovered she had been pregnant, prompting police to search for a baby near her home.
"The woman did everything she could to keep the pregnancy secret," Chief Inspector Andreas Mölle said.
Police are investigating the mother for attempted manslaughter.
jsi/amp (AFP, dpa)