The woman, a resident of the city’s eastern Widzew district, was charged with abusing the child with particular cruelty and causing bodily harm.
She faces up to 10 years in prison if convicted.
The baby remains in hospital. Doctors found fractures to both arms and one leg, as well as bruising on his body, state news agency PAP reported.
The mother said the boy had been injured while she was changing his diaper, but a doctor concluded that the injuries could not have resulted from an accident and were caused by violence, police said.
A court rejected a request from prosecutors to place the woman in pre-trial detention. She has instead been placed under police supervision.
"The family court will now decide the child’s future," Paweł Jasiak, spokesman for the District Public Prosecutor’s Office in Łódź, said.
The boy is the woman’s first child.
Police became involved on August 26 after an acquaintance of the mother called emergency services.
The woman told police she had received an online message from the mother indicating that she had hurt her child.
She said she urged the mother to take the baby to hospital and then contacted the authorities.
Police spokeswoman Kamila Sowińska said locating the mother proved difficult because the two women knew each other only through the internet and the person who raised the alarm did not know where the suspect lived.
Officers checked possible addresses based on the mother’s history and eventually reached an apartment where she was believed to live with the child and her partner.
They found the child’s father outside the building. He told officers that, according to his partner, the baby had been hurt during a diaper change.
Police later located the mother at the hospital and detained her after receiving the doctor’s assessment of the child’s injuries.
Officers also detained the child’s father after checking his identity and discovering that he was wanted under an arrest warrant to serve a prison sentence.
(rt/gs)
Source: IAR/PAP