Reginald Dixon, an obstetrician and gynaecologist, aborted the 11-week- old foetus without consent during a routine hysterectomy operation.
Mr Dixon, 58, was found not guilty of unlawfully procuring a miscarriage during an operation on Barbara Whiten, in March 1994 at the King's Mill hospital, Sutton-in-Ashfield, Nottinghamshire.
"I felt I had made a particularly hard and difficult decision which has turned out to be wrong, which I very much regret," he said.
Mr Justice McCullough said Mr Dixon, who is regarded as an eminent and caring physician by his colleagues, could not have been absolutely certain that Mrs Whiten was pregnant.
"She was lying on the table with her abdomen open and her uterus exposed. This was the situation in which Mr Dixon had to make up his mind."
Nottingham Crown Court was told that Mrs Whiten, a part-time university lecturer, now 38, was not told of her pregnancy until after the operation. She said she was devastated by the news and that, although on the pill at the time, she "would have loved to have had a baby", but believed she was infertile.
During surgery, Mr Dixon noticed a swelling of the womb and realised there was a possibility that his patient was pregnant. He decided to go ahead with the operation after failing to contact her husband, and consulting medical notes which revealed she had previously overdosed on anti-depressants. Mr Dixon believed Mrs Whiten could not cope with an unwanted and unplanned pregnancy and if she had the baby there would have been a grave risk of permanent injury to her mental health.
"The easiest thing for me to do would have been to take a look, closed the abdomen and walked away. I was trying to do the best for my patient, but that would have been doing the best for myself," he said.
He also feared the foetus might have been abnormal because of drugs Mrs White had taken for suspected endemetriosis, a painful spreading of the womb lining, which was the reason for the original operation. He added that her age, then 35, also influenced his decision.
The jury ruled that Mr Dixon, who will soon return to King's Mill, acted within the law in an emergency situation, where his patient's mental health was at risk.
"It is a great relief to see the end of nearly three years of severe stress for me, my family and, of course, Mrs Whiten," he said.
Mrs Whiten, who broke down and sobbed loudly as the verdict was announced, is believed to be pursuing a civil action for damages.
In a brief statement her solicitor said it had been "a very rough and difficult three weeks" for Mrs Whiten and her family.Reuse content