Pregnant teachers are raising concerns about having to go back into the classroom with unvaccinated students.
Teacher's are ''losing sleep'' thinking about returning to the classroom, according to the Association of Secondary Teachers.
The ASTI is calling on the Education Minister to examine the issue.
The union wants those who are due to have a baby to be allowed to work from home.
Teachers who were pregnant before the Summer holidays were allowed to work remotely, but are now being asked to go back to school.
General Secretary of the ASTI Kieran Christie says the situation is distressing:
"Many of these teachers are telling us that their consultant are advising them not to return to work, because their professional view is that it is unsafe. On the other hand the Department of Education and [...] Medmark are telling them that they should. You can imagine how stressful for a pregnant teacher when you're sandwiched between those conflicting opinions."