The horrific incident occurred after the child became stuck as it was being born in Aracaju, northeastern Brazil.
The baby boy's headless body remained inside the mother and had to be removed by Caesarian.
Tragic: The 22-year-old mother, who has three
other children, was rushed for an emergency Caesarian where, according
to the woman, the headless body of the baby was removed (file pic)
The 22-year-old mother, who has three other children, told her family she knew something was wrong when she heard something 'crack'.
Gilmara Azevedo dos Santos, the woman's cousin, told Brazil's Globo G1 website: 'She went through a lot of suffering, it was hours and hours and a lot of pain and discomfort, with doctors pushing on her stomach, trying everything to make the baby come out.
He said the mother asked what was happening but didn't get an answer.
She was rushed for an emergency Caesarian where, according to the woman, the headless body of the baby was removed.
Ms Santos added: 'My cousin is totally devastated, the whole family is in shock. She is still in so much pain, as after the head had been pulled off they tried to get the body out by cutting her. In the end they had to open up her body to take out her son's dead body.'
The hospital's clinic director Debora Leite today said that a committee of professionals had been set up to investigate the baby's death.
The family confirmed they intend to sue for medical negligence.