Doctors in Florida have pulled off a medical first that saved the lives of a pregnant woman and her triplets twice over, defying a rare neurological illness that nearly killed all four.

Andrea Temperino, 34, was left close to death and reliant on a mechanical ventilator to breathe for her when she developed a complex form of the neuromuscular disease Myasthenia Gravis eight weeks into her pregnancy. It is the only known case of its kind involving a patient with unborn triplets.

After seven weeks in hospital, she recovered. But three months later, she suffered a second life-threatening condition that left doctors with only minutes to save her and her babies.

Temperino and her infants, who were delivered by emergency C-section at 30 weeks gestation, are now doing well at the University of Miami's Jackson Memorial Hospital.

"We must have had someone watching over us, to have found these people who saved my wife and my babies' lives – not once, but twice," said Anthony Temperino, also 34. "Without them, for sure, all four would have been dead." Andrea said: "They are my little miracles. I'm just so happy it's all over and we have the lives of our three precious babies."

The Temperinos, of Coral Springs, Florida, were told by fertility specialists eight years ago that they had a "0% chance" of having children of their own but, after lifestyle changes that included transitioning to an all-organic and natural diet, celebrated the arrival of their first child, Ayden, last year following in-vitro-fertilisation treatment.

In June this year, following the implant of two more fertilised eggs, Andrea Temperino discovered that she was pregnant again – this time with triplets. But the joy was short-lived as her health inexplicably deteriorated, leaving her struggling to breathe and swallow and with a severely drooping eyelid, confounding doctors at the first hospital where she sought help.

"I was having to beg and plead, I was calling war. We were getting nowhere with finding out what was wrong with her, or even getting some of them to acknowledge that there was anything wrong with her," Anthony Temperino said.

Taking the decision after 10 days to seek help elsewhere, he took his wife to the emergency room at Jackson Memorial Hospital.

"At this point she can't breathe properly, she can't walk, she can't swallow. She's just trying to survive. I was praying: 'Please God, let the doctors figure this out because I'm going to lose her,'" he said.

She was diagnosed within hours as having Myasthenia Gravis with MuSK, a chronic, auto-immune neuromuscular disease in which antibodies attack the receptors that allow brain signals to reach the body's muscles.

As doctors struggled to bring the condition under control, she ended up in intensive care for eight days, where doctors inserted a breathing tube to keep her alive. "They said 'We need to do this quick, she's leaving us,' and I said 'Where's she going?' I didn't realise at first what they meant," said Anthony Temperino, a commercial pilot.

Dr Shahnaz Duara, medical director of the neo-natal intensive care unit at Jackson's Holtz Children's Hospital, said: "What's truly amazing is that Mrs Temperino was at one point so close to collapse, so sick, and yet none of that seems to have transferred to her babies. Her obstetrician had said to me: 'I don't know if I can get her to a point where there will even be any babies for you to take care of.' It was a very serious situation but through it all, those three babies hung in there."

After seven weeks in hospital she was discharged, only to suffer a further emergency three weeks ago when the babies' placenta separated from the wall of the uterus – a life-threatening condition known as placental abruption, causing massive bleeding.

Within 15 minutes, she was in an operating theatre surrounded by 25 doctors. Identical twins Austyn and Alexander, and fraternal triplet Ashton were all delivered within one minute. All are now thriving and expected to survive.

Andrea Temperino's neurologist at Jackson, Dr Ashok Verma, said that the case is "one for the medical history books."

"For a while it was a hard situation … MuSK doesn't respond to the usual medication for MG – in fact she didn't respond at all – and it took a long time to turn things around. I told her 'You are my most precious patient, because there's not just one of you but three other lives to take care of.' I wanted to come out of this with all four of them and we did."

He added: "And after all that, this crazy woman was telling me yesterday: 'Next, I want a girl.'"