A teaching assistant suffered a miscarriage after a pupil kicked her in the stomach, a survey by UK trade union GMB union found.
She is among the more than half of school support staff in Britain that have suffered violence at work, with some threatened by parents.
Assaults named by members of the union included stabbings and attempted strangulation by an eight year old.
Teaching assistants and other school staff have said they were kicked, punched, and bitten.
One person told GMB they had faeces thrown at them, while others said they had been spat at and had their hair cut off.
The anonymous teaching assistant said: "I was pregnant and a child kicked me really hard. After that incident I started bleeding and lost my baby.
"I fell into a deep depression, especially as the school did nothing to support me."
A survey of almost 4800 school support workers revealed a catalogue of violent incidents involving children as young as eight.
Just over half said they had experienced violence at work, with more than 770 saying they were attacked every week.
One support worker had a chair thrown at her. Another had a piece of cement thrown at him.
One suffered a concussion by a "large 19-year-old boy" and another said she had a door slammed on her hand and sustained a broken bone.
Karen Leonard, GMB national officer, said: "These stories from the frontline by GMB's school staff members are truly disturbing.
"They can face a litany of violence that would constitute criminal offences in other jobs.
"No-one should be physically threatened at work. Violence from parents in particular is completely inexcusable.
"School support staff love their jobs, love the kids and want to carry on doing their best for the children.
"All they ask is their school backs them up when it does happen - and takes the common-sense steps needed to protect them.
"Throughout this year we have been asking schools to sign up to GMB's code of conduct to ensure attacks on members, when they happen, are dealt with properly."
School standards minister Nick Gibb said: 'Teachers and school staff have a right to feel safe in the workplace and any form of violence towards them is completely unacceptable.
"We have given schools the powers they need to deal with harassment of staff, and we expect them to have procedures in place to support staff dealing with issues like this."