A 36-YEAR-OLD woman desperate for another child died during an operation to treat her infertility, a Coroner's Court was told. A jury yesterday returned a verdict of death by misadventure on hawker Lau Tsui-chun, after hearing that she died at the Baptist Hospital on February 22 of complications caused by an air embolism - blockage of an artery by air or blood bubbles. Coroner Rodney Venning was told Lau gave birth to a baby girl three years ago. However, she had failed to conceive again and consulted private practitioner Dr Andrew Ho last year. The air embolism arose through air entering the blood stream in the uterus during the operation to unblock a fallopian tube. Dr Ho testified that he was trying to find out whether muscle spasms had temporarily caused the blockage of Lau's fallopian tubes. He tried a dye test, which was inconclusive, then injected 40 millilitres of air into Lau's body. According to evidence, 100 millilitres of air would have impaired the function of the heart to the point that it failed. Lau died despite resuscitation. In his summing-up, Mr Venning told jurors that theoretically there was an anticipated risk of air embolism, although this was the first such case found in Hong Kong during this type of operation. Expert witness Dr Ho Pak-chung, reader of the Department of Obstetrics and Gynaecology at the University of Hong Kong, considered what Dr Ho did was acceptable, although he would have undertaken a different procedure. He said the medical procedure used by Dr Ho had been used by other gynaecologists. Mr Venning said Dr Ho Pak-chung's testimony alone removed any possibility of a verdict of a lack of care, or the words ''aggravated by a lack of care'' being added to the verdict.