A woman who underwent IVF treatment to have triplets died just over a week after their birth from an undetected heart condition, Winchester Coroner's Court heard.
Isabel Mason, 34, had triplets, Mattias, Lukas and Sarah, delivered four weeks early in a planned Caesarean section on March 2 last year. She was kept in the Royal Hampshire County Hospital for observation after suffering from pre-eclampsia and anaemia, which left her weak, dizzy and short of breath
Eight days later, the court heard she was joking with staff about needing a bigger car to fit her children in and was about to have a blood transfusion when she told anaesthetist Dr Nicola Bosley that she felt odd before "her head rolled back". Mrs Mason died 35 minutes later, despite attempts to revive her.
"One minute, Mrs Mason was talking about the babies' buggy and how she needed a bigger car - the next she passed out," midwife June Phillips said.
"At first, we thought she had fainted but it soon became clear it was more than a faint because she was so limp."
A post-mortem examination revealed that the mother had died of haemopericardium, a condition when blood leaks into the sac surrounding the heart from a tear in an artery. The inquest heard that Mrs Mason, who came from Weeke near Winchester, had suffered two tears in her aorta, 3.5cm and 2.2cm long.
Martin Pitman, a consultant in obstetrics and gynaecology at the hospital said: "Aortic dissection is a phenomenally rare event, and this is only the second case in 20 years that I have had even peripheral contact with."
"It is difficult, if not impossible, to know if it just burst or if there was a gradual seepage of blood.
"The evidence would suggest it was a sudden burst."
In a statement, Mrs Mason's husband Paul said: "Isabel was overjoyed to be having a family and introducing the triplets to all the experiences we both loved.
"Sadly Isabel only had eight days with the triplets between their birth and her unexpected death. As the triplets have grown and their personalities have developed I regularly see so much of Isabel in them. From facial expressions to personality traits such as her characteristically determined happy-go-lucky mischievousness.
"Sadly she didn't have the opportunity to watch her children grow and introduce them to all the things she enjoyed from her cosmopolitan background. We feel extremely sad to lose Isabel; she has left a huge gap in all our lives."
Central Hampshire coroner Grahame Short recorded a verdict of death by natural causes, saying the accident was a rare occurence that could not have been detected and was impossible to repair once it had happened.