A coroner has found that it is 'inherently dangerous' to share a bed with an infant.

SIDS risk ... Co-sleeping an "inherently dangerous" act, coroner says.

Parents sleeping in the same bed or even on a sofa with their babies are putting their children's lives at risk, a Victorian coroner has said.

Coroner John Olle said a parent sleeping in the same bed with an infant aged under 12 months was "inherently dangerous", following his investigation into four babies who died of SIDS after co-sleeping.

I am satisfied sharing a sleep surface with an infant is an inherently dangerous activity 

Mr Olle found babies should sleep on their back in a cot in the same room as their parents for the first six to 12 months of life.

"I am satisfied sharing a sleep surface with an infant is an inherently dangerous activity," he said in the Victorian Coroners Court.

"Caregiver/infant sharing of sleep surfaces, beds, sofas, mattresses and armchairs, increases the risk of infant death from a fatal sleep accident, and may increase the risk of infant death from SIDS."

Judge Olle recommended a consistent and clear message on the risks of co-sleeping be provided to parents before and after the birth of a child.

The findings echo the statements made on the Sids And Kids website, which recommends that "after feeding and cuddles, baby is placed into their own separate and safe sleeping place, next to the parents’ bed."

"Experts agree that it is important for parents to be in close sensory contact with their baby, and they also agree that a cot or bassinet next to the parents bed achieves this closeness," it reads.

AAP