A soon-to-be mother is in hospital and a 14-year-old boy in custody, after a violent home invasion in which the pregnant woman was stabbed in the chest and stomach in Sydney’s north on Thursday night.

Neighbours have described the screams of Pie-Jiun Cheah, a 33-year-old physiotherapist, after the bloody attack in her Mount Colah home, shortly before 9pm.

Pei-Jiun Cheah (right) - the victim of a home invasion and stabbing attack in Mount Colah overnight. Credit:Facebook

"She just knocked on our door and said 'I've been attacked help me, help me'," neighbour Mark Bolger told reporters on Friday.

"We could see blood but not her actual wound. She was just totally distressed as we tried to ask her questions to get more information but she was so stressed she just couldn't speak about many other things."