The document was handed out to students at Dixons Academy, Liverpool, and the school have since stood by the contentious tactic.
The paper has left parents furious at what their children are being told, The Liverpool Echo reports.
One mum slammed the school for “massively stereotyping” and stigmatising young parents, as well as being completely wrong.
The “offensive” statement on the worksheet reads: “Young people who truant are more likely to use alcohol or drugs” and another said that students who miss school were “more likely to become young parents.”
The statements were among 10 made on the worksheet handed out to children in the academy’s isolation unit, known as Mountain Support.
It asked children to identify which of the statements were true, including: “young people who regularly skip school are more likely to have early sex”.
Another statement read: “Young people who truant or get involved in crime or anti-social behaviour can seriously harm their future education and chances of getting a job.”
The sheet claimed all 10 statements are true and “if you truant, you put yourself at risk.
“However your behaviour also impacts others around you including your family, your friends, teachers and staff at school and others in the community.”
One mum, whose son was handed the worksheet, branded the document as “ludicrous”.
She said: “When he should have been in class instead of learning he was asked to reflect on these issues. Apparently if you truant then you are more likely to have sex or have no friends in your life.
“This is ludicrous. I particularly take offence to the comment about young parents, a lot of the kids in that school come from so-called young parents.
“They are massively stereotyping the local community as well as stigmatising being a young parent as bad as associated with bad behaviour in school.
“Not only is it offensive but completely wrong.” Parents are said to be “at the end of their tether” with the school in search of answers around the document
One added: “Our biggest concern is the lack of work provided while in so-called isolation. The kids should be learning whether in isolation for punishment or not, how can the kids go back to class not knowing what work has been missed?
“In any event this particular sheet of paper is alarming.”
A spokesperson for Dixons Academy defended the document and said the school was making students aware of issues “so that they are better prepared to make decisions around keeping themselves safe.”
In a statement, the spokesperson said: “Safeguarding all of our school community is our main priority, part of ensuring that children are kept safe is to help them to be aware of the risks they could face in the wider world.
“We work with students to make sure they understand these risks so that they can make better decisions.
“One area of concern are the risks that children who truant could face while being absent from school.
“Children who truant are more at risk of a range of issues including lower educational outcomes, sexual exploitation, involvement in criminality and other risk-taking behaviours.
“We make students aware of these issues so that they are better prepared to make decisions around keeping themselves safe.
“We want students to be educated in a safe learning environment that prepares them for later life and not be left at risk.”