A pregnant woman is suing her health trust after she was forced to conceive using a donated egg because of delays in treating her.
Greta Mason, 42, claims a barrage of unnecessary fertility tests followed by a six-year wait for treatment meant her eggs were too old to be used and she could only conceive using a donor.
She is upset that she will now give birth to a baby to which she is not genetically related, and claims earlier tests showed it was her husband who had the fertility problem.
Mrs Mason, from Worthing, West Sussex, claims that when she was finally given a clean bill of health, she and her husband Chris were kept on an NHS waiting list for four years before they even got an appointment for IVF.
Then when they had treatment after a further two years, doctors discovered that Mrs Mason's eggs were too old to be used and she could only conceive using an egg donor.
Mrs Mason, who expects her baby next week, said: 'Whilst I am sure I will love this baby when it arrives, I am absolutely devastated that it is not genetically mine.
'I had always dreamed of having my own flesh and blood child who will inherit my genes so it was an absolutely shattering blow.
'But the hospital failed to monitor my hormone levels and did not notice that my ovaries were getting too old to undergo fertility treatment.
'I always wanted a baby with my husband but the truth is that this baby is genetically another woman's, and at times during my pregnancy, because the baby is not related to me, I have simply felt like an incubator.
'It is so upsetting to think had we not had to wait four years just to get an appointment, we could have had our own genetic child by now.
'Chris and I know we are having a baby boy and are very much looking forward to having him but I also feel terribly sad because I will never look at my son and think, "He's just like me".'
Mrs Mason and her husband, a 43-year-old bus driver, married in 1993 and started trying for a baby in 1995, when Mrs Mason was 29.
After two years without success, they began fertility investigations.
It was soon discovered that Mr Mason had a problem, but doctors insisted that Mrs Mason should also have a range of tests, even though she had become pregnant in an earlier relationship, and miscarried.
'Unsurprisingly, all the tests came back showing my uterus was healthy and my eggs were normal,' she said.
At last, the couple were put on an NHS waiting list for IVF treatment. But after six years, when the treatment started, Mrs Mason was given the shattering news that her ovaries were too old.
'We have since discovered that whilst I was on the waiting list my hormone levels should have been checked twice a year to ensure I was not nearing the menopause,' she said.
'If this had been done, the doctors would have had an early warning that my eggs were getting too old to be used for IVF and they could have brought us in for treatment earlier.'
Having been told their only hope was an egg donor, the couple found there were virtually none in the UK and were forced to seek private IVF treatment in Spain, where donors are guaranteed anonymity and are more plentiful.
Mrs Mason said: 'Because fairhaired donors are rarer in Spain, guaranteeing a baby with blue eyes like me would have meant a wait of another year in Spain, so we opted for the next available donor.
'This means our baby might well have brown eyes and will not have any of my fairer characteristics. But I couldn't deny Chris his chance of having a baby.
'Whilst we were thrilled to be having a baby at last, I couldn't help feeling how unfair it was that although I did not have any fertility problems, I was the one who ended up without a genetically related baby. It has put a huge strain on our marriage.'
The couple have been forced to remortgage their house to pay for their Spanish treatment, which cost £15,000.
A spokesman for Oliver Swain and Co solicitors confirmed that they have taken instructions from Mr and Mrs Mason to sue Worthing and Southlands PCT.
