THE medical profession last night applauded an appeal court's decision to uphold a conviction against a doctor described as being ''a professional abortionist''. In what is believed to be the first case of its kind involving a registered doctor, Lai Sau-kuen, 53, lost her appeal in the High Court yesterday to overturn a conviction for performing illegal abortions at her Mongkok clinic. She will now be investigated by the Medical Council and almost certainly faces being struck-off the medical register. Professor Rosie Young, Medical Council chairman and vice-chancellor of Hongkong University, said: ''She will automatically have a disciplinary hearing, and it is a likely possibility that she will be struck off. This is a serious offence and will act as a deterrent.'' Under Hongkong medical law, disbarment for a criminal conviction is not automatic, and Lai was back seeing patients at her Fa Yuen Street clinic hours after leaving court. ''I don't want to talk any more about these bad memories,'' she said. ''I'm very busy seeing patients.'' Some doctors are highly critical of this arrangement, claiming a criminal medical conviction should, at least, result in immediate suspension of practice. Dr Theresa Howard, of Maryknoll hospital, said: ''The Hongkong Medical Association indicated recently that anyone who is convicted should be liable to be struck off the register, and that's what should happen to this doctor. ''It should be a warning to the rest of the medical profession who do this sort of thing.'' Any registered doctor is legally permitted to carry out abortions in certain Hongkong institutions, a law which has also been criticised, but moves are underway to create a specialist gynaecology and obstetricians register. The Chinese-trained Lai also failed in her appeal against a three-year prison sentence, suspended for two years, and a $250,000 fine. At the original trial, Deputy Judge Sharwood described this figure as equivalent to six months' salary for the doctor. He said there were ''cogent reasons why she should not be sent to prison, including the fact her medical career would be in ruins, and the embarrassment and suffering she had undergone''. The trial was in May last year, and weeks after she walked out of court on that occasion, Lai was again offering to carry out apparently illegal abortions. In what became an award-winning investigation, the Sunday Morning Post published an expose on Hongkong's thriving and lucrative illegal abortion trade. Post reporters highlighted the case of Lai, and other unscrupulous abortion doctors, by posing as a young couple with an unwanted pregnancy. Yesterday's Court of Appeal, comprising Mr Justices Kempster, Litton and Bokhary, rejected the argument put forward by defence counsel Neville Sarony, QC, that the jury which found Lai guilty had not been properly directed at the original trial. In her defence, Lai, who qualified in China and sat the licentiate examination to practise in Hongkong, had told the court the victims had already had a spontaneous miscarriage, and all she had done was perform a ''clean-up'' operation. She had not told the patients they had miscarried because an abortion fee had already been agreed. The Court of Appeal was told the defence application was: ''Since the defence was so lacking in real merit it was incumbent on the judge to carefully sum up the case before the jury . . . Proper consideration of the case should not be swamped by the applicant's own admission of deceit.'' However, Mr Justice Litton said it was an ''extraordinary coincidence that within about one month two women in early stages of pregnancy with no previous gynaecological problems were found upon examination to have already miscarried''.