Lauren Jane Curnow, 18, of Cambridge St, pleaded guilty in the Victorian Supreme Court to one count of infanticide.

She was convicted and released on the good behaviour bond, with a condition that she undertake counselling and treatment as directed by her psychologist.

In sentencing Curnow, Justice Bernard Bongiorno said infanticide was a form of culpable homicide and carried a maximum penalty of five years' jail.

"It is a very serious offence ... It's an offence which strikes at the sanctity of human life as our society understands it," he said.

"Society must protect those weakest of its members, who are placed in vulnerable positions. The circumstances in which you killed your little boy, he was the weakest member of society."

But Justice Bongiorno said he did not believe jail was the appropriate penalty for the teenager, who was just 17 when she committed the offence.

"I'm satisfied that the interests of the community and your interests will be best served by your becoming a useful member of society and certainly not going to jail," he said.

Earlier, Crown prosecutor Jeremy Rapke, QC, told the court Curnow became pregnant while studying Year 11 at Ballarat Secondary College, but hid it from her family and friends.

She gave birth to a baby boy on her bed about 4pm on August 17 last year, while her mother Debra was outside washing the car.

The court heard that after the delivery, Curnow cut the umbilical cord with scissors and repeatedly punched the baby to the head.

She then wrapped the boy in a towel, placed him beside her bed and had a shower in the bathroom.

Mrs Curnow later discovered the dead baby beside the bed and took him and her daughter to Ballarat Health Services Base Hospital.

Curnow had not previously sought medical treatment for her pregnancy.

Mr Rapke said while it was not known how many times Curnow had hit her son, a post-mortem examination showed the baby had suffered multiple skull fractures.