Simon Parsons, 54, has been struck off from the profession almost two years after he was jailed for the four-year relationship.
He first taught the girl when she was 15 years old and a year later he began kissing and touching her, a hearing heard.
When she turned 17 they started having sex after Parsons, who was 26 years older than her, whisked her off to London on a theatre trip.
The relationship continued and the pair had sex on multiple occasions, including on the premises of Castle School in Thornbury near Bristol.
And the affair continued after the teenager left school and gave birth to Parsons’ son, teaching watchdogs were told.
Parsons was caught in March 2014 after the pupil told her aunt what had happened.
In November he was jailed for 12 months after he admitted to five specimen counts of abusing his position of trust by sexual activity with a female aged 13-17.
He was also forced to sign the Sex Offenders” Register.
Parsons, of Dursley, Gloucestershire, was banned from the job for life by the National College for Teaching and Leadership.
He has now been released from prison, but failed to turn up to the hearing in Coventry.
Decision maker Alan Meyric, for the Education Secretary, said: “She was left feeling confused, lost and let down by a teacher to whom she looked up and trusted.
“The panel accepts that Mr Parsons had a previous good record and was talented teacher.
“However, his actions were deliberate and sustained.”