A neighbour has found a heavily pregnant woman screaming and slumped in his doorway after she was stabbed during a violent home invasion.

The 33-year-old woman, who is seven-months-pregnant, was stabbed multiple times in the stomach, chest and arm in her Mt Colah home in Sydney's north about 9pm Thursday.

The 14-year-old intruder was arrested after he was found at a nearby home in Beechworth Place about an hour after the horrific incident with stab wounds to his hands.

Neighbours yesterday detailed how they ran outside to find the woman 'screaming and extremely stressed'.

Mark (pictured) revealed he found his heavily pregnant neighbour screaming and 'very stressed' outside her home after the Thursday night stabbing

Joanna Diment said she and her husband Adam held the woman as she bled profusely.

'She was just slumped in the doorway, I think she was holding her side, they put blankets around her,' Mrs Diment told The Daily Telegraph.

A second neighbour, Mark, said he phoned Triple 0 and stayed with the woman until paramedics arrived.

'She was very stressed, very, very, very stressed, which she would be you know, home by herself,' he told Seven News.

The woman was rushed to the Royal North Shore Hospital, where she remains in a stable condition.

The condition of her unborn baby is unknown.

Forensic police are pictured at the northern Sydney home where the 33-year-old woman was stabbed during a violent home invasion

Police at the scene after a seven-months pregnant woman was stabbed multiple times at a home in northern Sydney

The alleged intruder is under police guard at Hornsby Hospital awaiting surgery for his hand wounds.

Blood stains reportedly remain on the doorstep of the neighbour's home, where the 33-year-old begged for help.

New South Wales Police are investigating.

Police established a crime scene at the Mt Colah home on Thursday evening as they launched an investigation into the incident