She was tested for a condition called Hughes Syndrome.

Often known as "sticky blood", this is a condition in which there is increased risk of clotting of the blood.

Twenty years ago most miscarriages were regarded as unknown cause, but it is now known that one in five recurrent miscarriages are due to Hughes Syndrome.

Due to the blood clotting tendency in pregnant women with Hughes Syndrome, clots block the placenta causing it and the baby to wither and die. Tragically many women suffer repeated miscarriages (commonly six or more and as many as 38 in one extreme case) and these can occur at any time during the pregnancy, including stillbirths.

Hughes Syndrome is easily diagnosed by simple blood tests and pregnant women can be treated using junior aspirin and heparin injections to thin the blood. This treatment has been shown to be extremely effective and raising successful pregnancies from a low of 20 per cent to 85-90 per cent. But two positive tests eight weeks apart are required for diagnosis.

Gill from Sheffield says: "I was lucky to be treated by Prof TC Li and his team at the Jessop Wing in Sheffield, one of only a handful of miscarriage clinics in the country. I had one positive test and one negative and so was declared to be free from the condition.

"However, my intuition told me that this was what was causing the miscarriages and I insisted on a third test as I wasn't prepared to go into another pregnancy with those 50/50 odds. The test came back positive and I have since come across others to whom the same has happened."

According to the Hughes Syndrome Foundation, this is not an uncommon picture as the condition is cyclical.

"If I had not pressed the matter, I would probably have continued to lose babies," says Gill.

She was given daily injections of blood thinning drugs and 10 months ago Gill gave birth to Nathan.

At Nathan's naming ceremony in the village of West Burton in the Yorkshire Dales, Gill and Zac decided that rather than accept gifts for their son, they would like to raise awareness and funds for the Hughes Syndrome Foundation which helps to fund research into the auto immune condition.

Johanna Frels also lost three babies to Hughes Syndrome. She says: "I urge couples not to give up hope when they have lost babies because of this condition, it is in most cases treatable with simple aspirin or heparin and the results are amazing."

Johanna is now a mum of three herself following treatment at the Jessop wing.

A spokesman for the Hughes Syndrome Foundation said: "The real problem is that a lot of GPs and hospitals don't know about the condition, so it often goes undetected or misdiagnosed – at the moment it's still relatively unheard of."

To make a donation, contact the Hughes Syndrome Foundation www.hughes-syndrome.org 0207 188 8217.

www.miscarriage association.org.uk 01924 200799.