Tragedy as mother who had gastric-bypass surgery so she could give birth dies from rare infection 'caused by the operation' Joanne Slater had the operation to control a hormone imbalance Doctors believed this was preventing her from becoming pregnant The insurance worker had suffered three miscarriages After the surgery she gave birth to Lily-Mai in 2009 The 38-year-old developed a rare infection and died on January 3 Doctors believe Joanne Slater may have died as a result of having a gastric band fitted in 2005 A mother who had gastric-bypass surgery to have the baby she longed for has died from a rare infection believed to have been caused by the operation. Joanne Slater, 38, from Stannington, Sheffield, had the operation to control a hormone imbalance which doctors thought caused her to gain weight and was preventing her from becoming pregnant. The insurance worker had suffered three miscarriages and tried dieting unsuccessfully before going under the knife in 2005 as a last resort when she reached 23st. At first the results were impressive and Mrs Slater lost half her body weight before giving birth to Lily-Mai, who is now aged four. However, she later developed serious nutritional deficiencies as well as a rare and deadly listeria infection discovered in her blood when she was admitted to intensive care at the Northern General Hospital. The mother went into cardiac arrest brought on by pneumonia and suffered devastating brain damage which led to the decision to switch off her life-support machine earlier this month. Michael Slater, Joanne's husband, said her death was "such a shock" and highlighted the potential risk involved with bariatric surgery. The cancer nurse, aged 47, said: 'When Joanne had her operation, it was still relatively new and doctors are now finding more patients developing problems further down the line. 'It's difficult - if she'd never had the operation we'd never have had Lily-Mai.' Close: Joanne Slater pictured with her husband Michael and the daughter she longed for Lily-Mai Mrs Slater, a former pupil of Sheffield's City School, met her husband when they worked together at a care home in Endcliffe, Sheffield. The couple tried for a baby for years. Mr Slater said: 'We'd almost given up hope. You name the diet, Joanne had tried it. She had hormone problems and was given the opportunity to have an operation. A gastric by-pass makes the stomach smaller, meaning patients feel full more quickly and reduces the amount of calories absorbed by the bowel. Devastated: Michael Slater holds a photograph of his wife Joanne who died earlier this month Mrs Slater had the procedure on the NHS at Thornbury Hospital, Sheffield, in 2005. Her husband said: 'She did very well initially, it couldn't have gone better. She was bright and bubbly, the life and soul of the party. As Mrs Slater slimmed down the couple took up active pastimes such as dancing and walking, and went on exotic holidays, including a trip to Africa in 2006 the same year they were married. Lily-Mai was born three months premature in 2009. Mr Slater said: 'Joanne was so proud. She was fantastic, everything you would want in a mum. But unfortunately her health got worse. Mrs Slater's weight loss became too extreme and she complained of muscle pains and tiredness. Doctors prescribed supplements for a lack of nutrients such as copper and vitamin D, thought to be a side effect of the surgery, but her health continued to decline and she developed a rare and deadly listeria infection in her blood. Mr Slater said: 'The listeria really wiped her out. I asked the consultants if they had any idea how it got there and they said no. It's a rare infection, they could only say it was probably related to the surgery.' She spent Christmas in hospital and went into cardiac arrest on New Year's Eve. Doctors managed to revive her but her brain was severely damaged due to a lack of oxygen. Happier times: Michael and Joanne Slater pictured on their wedding day in 2006 Mrs Slater's parents Rita and David and her brother Doyle gathered at her bedside when she died on January 3. Her funeral was held on Wednesday at Christ Church Stannington followed by a burial at Crookes Cemetery. Donations were collected for baby charity Tommy's and future fundraising events have been planned. Joanne Slater was admitted to the Northern General Hospital in Sheffield where she died earlier this month