Cherie 'must not blame herself'

Cherie Blair may have suffered a "bad luck miscarriage" which caused her to lose her baby, experts said today.

Professor Lesley Regan, head of Obstetrics and Gynaecology at St Mary's Hospital in Paddington, said: "It is very unusual for miscarriage to occur because you have done something wrong. The most common reason is a genetic abnormality, a 'bad luck' miscarriage, you might call it. Women often blame themselves for a miscarriage - and they shouldn't."

Experts said chromosomal damage in the egg was the more likely cause rather than anything to do with Mrs Blair's famously punishing schedule. Women in their late forties are particularly vulnerable, with up to half miscarrying.

Days ago, Mrs Blair was seen watching the closing ceremony of the Commonwealth Games in torrential rain as she again juggled her long hours as a high-flying barrister with fulfilling her public duties as the Prime Minister's wife.

But doctors said that neither the weather nor the stress of juggling private, public and family life could be blamed for her loss.

Miscarriage counsellors said it was important that women who suffer the loss of an unborn baby do not blame themselves.

Pregnancy rates for women over 40 have risen by 41 per cent in the past decade, mainly due to fertility treatment in which younger, more stable eggs are implanted to ensure a better chance of conception - and full-term pregnancy.

The biggest problem facing an older woman is the fact that their eggs are of poorer quality and therefore more vulnerable to damage in the crucial first few weeks of pregnancy.

While women aged 25 to 30 have a 16 per cent risk of miscarrying, by the age of 40 that has reached 25 per cent and by the age of 47, as with Mrs Blair, there is a one in two chance of losing the baby. This is because older eggs do not respond so well to the hormones released during pregnancy.

Peter Bowen-Simpkins, spokesman for the Royal College of Gynaecologists, said: "Over the age of 40 the chance of a chromosomal abnormality rises sharply, to around one in eight by the age of 50. Very often this leads to early miscarriage, between eight to 12 weeks of pregnancy."

Mrs Blair may not even have realised she was pregnant until the first symptoms of miscarriage, such as stomach pains or bleeding, began.

Fertile women in their forties have as little as a one in 20 chance of becoming pregnant naturally. By the age of 35, they are half as fertile as they were at 21, and most women have started the menopause by the age of 51.

But as women approach the menopause, their periods and egg production become erratic. Believing that they are no longer able to become pregnant, many stop using contraception - but this can be a mistake as they are still fertile and eggs are being produced.

Mr Bowen-Simpkins said: "It is unusual and unlikely, but it can still happen. Some women do start the menopause much later than others and therefore stay fertile longer. And if a woman is generally fit and healthy, it is always a possibility."

Two years ago Mrs Blair amazed medical experts - and her husband - by becoming pregnant at the age ofScientists now believe that a genetic fault may be the cause of most miscarriages. A defect in a gene called TBP makes the mother's immune system view the foetus as foreign tissue and attack it rather than nurturing it.

Recent research found that pregnant women who drink the equivalent of a bottle of wine a week may treble their chances of miscarriage.

Miscarriage can also be caused by an infection called toxoplasmosis, which is caught through contaminated meat, soil, milk or infected animals.

The risk of miscarriage decreases dramatically after the eighth week of pregnancy, so Mrs Blair may have only been carrying her fifth child for a matter of weeks.

She is most likely to have undergone a small operation called a D&C (dilatation and curettage) to reduce the chances of infection and stop any bleeding.

Recent research found that women are not given enough support as they try to cope with the feelings of grief and loss experienced after miscarriage.

Counsellors said Mr Blair's feelings should also not be ignored as sympathy inevitably focuses on his wife.

A study in the British Medical Journal last year said: "After a miscarriage, the father's feelings are rarely given consideration because of the assumption that they do not bond with the unborn child."