A young mother killed her newborn baby before placing the body in her handbag and leaving it in bushes under a tree when taking the dog for a walk, a court has heard.
Crown prosecutor Andrew Grant said the woman, 19, - who will not be jailed - waited eight days before telling her sister what had happened and they went to the police.
The woman, who cannot be identified, pleaded guilty in the Supreme Court on Thursday to infanticide.
She had been due to stand trial for child homicide, which carries a maximum penalty of 20 years, before pleading guilty to the lesser charge.
Infanticide, which under the Crimes Act is when a woman causes the death of her child when the balance of her mind is 'disturbed' after the birth, carries a maximum penalty of five years' jail. There have only been two other reported cases of infanticide in Victoria.
Mr Grant, who agreed not to read out parts of the prosecution summary which could distress the vulnerable young woman, said she had played basketball with her sister and partner of 18 months on February 25 last year before staying at her father's home.
She claimed not to have known she was pregnant despite not having had her period since June 2013, when she complained her stomach was hurting after dinner.
The woman gave birth to a baby girl weighing four kilograms in her bedroom in the early hours of February 26.
She later told police the baby was alive after the birth, moved her head and made a noise. She said she placed her hand over the baby's mouth to stop it from making more noise.
The woman claimed the baby's umbilical cord was wrapped around her leg and when she cut the cord, the baby did not respond and she realised the baby was dead.
She did not call triple 0 because she was scared and did not know what to do so she placed the baby in a 'Cotton On bag' in her room and went for a shower. She then used bleach to try to clean the bloodstains in her room before going to sleep.
The next day she continued to clean up the bloodstains and placed the bag into two garbage bags which she put into the green wheelie bin in the backyard.
When her mother came to pick her up two days later, she retrieved the bag containing the baby and placed it in her handbag. At about 7pm or 8pm, she took the dog for a walk and left the bag under the tree.
The prosecutor said the woman waited until March 6 to tell her sister what had happened and took her to the tree where she had left the baby.
Both women were crying when they drove to a nearby police station and the woman told police, "something bad has happened."
An autopsy was conducted but no cause of death could be established.
Justice Jack Rush, who indicated he did not plan to jail the young woman, had to briefly adjourn the pre-sentence hearing when she became visibly distressed and began sobbing.
Mr Grant said psychological reports indicated the young woman had been suffering from "pervasive denial" of her pregnancy, and her mental state altered when she saw the baby's head and realised she was giving birth.
The woman experienced an acute stress disorder, a feeling of disassociation and her mind was disturbed at the time when the child was born in a weakened state.
The prosecutor said there was no lawful justification for the young woman's actions when she failed to seek medical help for the baby.
Defence barrister Helen Spowart described the woman as a gentle, loving person devoted to her family who had been leading a quiet, law-abiding life.
Ms Spowart said the naive, vulnerable and frightened woman now suffered from agoraphobia, blamed herself for what had happened, struggled with nightmares and felt fearful and alone at night.
Ms Spowart urged the judge to place the woman on a community correction order given the circumstances of the case. The woman will be sentenced next week.
Justice Rush extended a suppression order banning the media from reporting anything that might identify the woman. The suburb where the baby's body was found is also suppressed.