After the student was asked to stand on a chair as a punishment, the two had a verbal exchange, in which the student repeated all the teacher's questions, belittling her in front of the class.
The teacher then referred to the girl being pregnant and said words to the effect of "if you think having an abortion makes you an adult then it doesn't''.
The girl, who had fallen pregnant and had an abortion earlier that year, left the class in tears.
The teacher reported the incident to the dean and principal at the end of the period, and was deeply remorseful of her actions, the decision said.
Counsel for the teacher, David Martin, said her judgement was clouded because she was emotionally fragile after a recent bereavement.
The tribunal, chaired by Kenneth Johnston, said the teacher had overcome adversity in her life and had a previously unblemished record.
She had abused her position in a way which was humiliating and painful for the student, but the incident was out of character and unlikely to be repeated.
The teacher was censured and ordered to inform any prospective teaching employer of the finding for a period of three years.