A pregnant woman critically ill with swine flu was being treated in a Swedish hospital today after being transferred from Scotland for specialised treatment.

The 26-year-old suffered a rare complication and was flown to Stockholm because no beds were available in the UK for the procedure she needed.

The Scot was admitted to Crosshouse Hospital in Kilmarnock, East Ayrshire, last week where she was put on a ventilator because of an extreme reaction to the H1N1 virus.

Earlier yesterday, a new website to diagnose people with swine flu crashed within minutes of launching after it was deluged with thousands of hits a second.

NHS Ayrshire and Arran's specialist intensive care team recommended that the pregnant Scot received a highly-specialised procedure known as extracorporeal membrane oxygenation (ECMO).

This involves circulating the patient's blood outside the body and adding oxygen to it artificially.

ECMO is a relatively new technique that is used when a patient's lungs are functioning very poorly even with ventilation and high levels of oxygen.

The UK has a national ECMO unit in Leicester but all five beds there are currently being used.

However a bed has been found in a similar unit in Stockholm and the patient was transferred under pan-European arrangements for sharing such scarce facilities.

A specialist medical team was sent from Stockholm and the patient was flown to Sweden, arriving at the hospital last night.

The health board said she had adult respiratory distress syndrome.

Dr Robert Masterton, executive medical director of NHS Ayrshire and Arran said: "Once an ECMO bed was identified in Sweden, our intensive care specialists worked closely with our Swedish colleagues to make sure the patient was stable before being transferred.

"The family have been fully involved in this decision and support this referral. They have asked for privacy while they concentrate on the patient's treatment and recovery."

Scottish health secretary Nicola Sturgeon said: "This woman has suffered severe complications and requires urgent and highly specialised treatment.

"It is therefore absolutely right that she is transferred to Sweden for treatment which could save her life."

Speaking on BBC News 24 last night, Ms Sturgeon said health services in Scotland were coping with the swine flu outbreak and agreed levels of the illness were low compared to England.

She said: "In Scotland one of the advantages we have at the moment of our relatively low level of flu is that our GP services and NHS 24 are coping with demand so we haven't had to switch on the pandemic flu service today as has been the case in England.

"We don't yet have the levels of flu to necessitate the switch-on of that service."

The Government said last night that a new website to diagnose people with swine flu was experiencing "unprecedented demand".

The system, which launched at 3pm yesterday, was receiving 2,600 hits per second - or 9.3 million hits per hour - at around 5pm.

The website crashed within minutes of launching but appeared to be running normally a short time later.

But the Government admitted it was having to increase capacity due to demand.

It comes after new figures showed there were an estimated 100,000 new cases of swine flu last week - around double the 55,000 in the previous week.