Prince Edward's wife Sophie has been putting on a brave face after losing her six-week-old baby because of an ectopic pregnancy. She was rushed by air-ambulance last Thursday for an emergency operation at the private King Edward VII Hospital in central London, which she left yesterday.

The 36-year-old Countess of Wessex spoke of her sadness at losing her first baby - but remained optimistic she and her husband could still start a family.

"I'm obviously very sad - but it was just not meant to be," she said. "But there will be other chances."

She is right to be positive. Dangerous as an ectopic pregnancy can be, many sufferers do go on to give birth to perfectly healthy children.

York GP Dr Sarah Bottom says it is possible Sophie and Edward could still go on to have a family of their own.

"It depends on the extent of the surgery," she says. "Normally you would expect to lose one ovary as a result of surgery. But assuming that the other one is still in good working order, lots of people have successfully achieved a pregnancy following an ectopic."

The condition is more common than many people think - one in 100 pregnancies is ectopic. But, according to the Ectopic Pregnancy Trust, about 65 per cent of women who suffer such a pregnancy will become pregnant again within 18 months.

The actress Amanda Redman, who is the Trust's patron, has herself suffered two ectopic pregnancies. The first was diagnosed fairly early, but the second was more serious. She was making a film with Griff Rhys-Jones and had told everyone on the set she was having a baby.

"We were about to shoot a film and I really wasn't feeling well," she says in an interview published on the Ectopic Pregnancy Trust website. "The cameraman was looking through the view finder at me, setting up the shot, when he suddenly went 'Oh my God. Look at Amanda, she's gone grey!' All the colour had drained out of my face and I had this deathly pallor. Everyone insisted I go straight to hospital."

An ectopic pregnancy was diagnosed. As Amanda was wheeled into the operating theatre she believed she was going to die and began to cry. All she remembers of the operation is that as she went under the anaesthetic she kept repeating a message to her little girl: "I love you, Emily."

She was back at work within three weeks. "But even so, I felt very frail and very vulnerable... emotionally I'm still not over it, even now seven years later."

Having experienced two such pregnancies, Amanda Redman agreed to become patron of the Ectopic Pregnancy Trust. "I feel anything that can help make people more aware is extremely important," she says.

So what are the facts about ectopic pregnancies? Below, with thanks to the Ectopic Pregnancy Trust, are a few of the more common questions - and some answers.

What is an ectopic pregnancy?

Put very simply, an ectopic is "an out-of-place pregnancy". It happens when a woman's ovum, when it has been fertilised by a man's sperm, instead of moving down her fallopian tube into the womb to develop there, remains "stuck" in the tube.

What are the causes of an ectopic pregnancy?

The most common reason for an ectopic pregnancy is damage to the fallopian tube, causing a blockage or narrowing. There could also be a problem with the walls of the tube, which should normally contract and waft the fertilised egg into the womb. Conditions such as appendicitis or pelvic infection can damage the tube by causing kinks or adhesions, thus delaying the passage of the egg, allowing it to implant in the tube. In most cases however, the cause of the ectopic is not known

What are the symptoms?

- Abdominal pain, which can be persistent and severe. The pain may be on one side, but not necessarily on the side of the ectopic

- Shoulder-tip pain

- Abnormal bleeding, which may be heavier or lighter than usual and prolonged. Unlike a period, this bleeding is often dark and watery, sometimes described as looking like 'prune juice'

- A missed or late period

- Bladder or bowel problems. Pain when moving the bowels or on going to the toilet

- Pregnancy test (urine). This may be positive but not always

- Sickness and diarrhoea. Often confused with gastroenteritis

- Collapse. You may be feeling light-headed or faint, and often this is accompanied by a feeling of something being very wrong.

At what stage in pregnancy are ectopic pregnancies most likely to occur?

Ectopic pregnancies usually cause symptoms which lead women to seek help between the 4th and 10th week of pregnancy and most commonly between 6-7 weeks.

Is it possible to have another ectopic pregnancy?

The overall chances of a repeat ectopic pregnancy are about ten per cent and this depends on the type of surgery carried out and any underlying damage to the remaining tube(s).

What are the chances of a future successful pregnancy after an ectopic pregnancy?

This very much depends on the condition of your remaining tube(s). The loss of a tube does reduce success rates, but you can still become pregnant and have a successful pregnancy with only one tube intact. Overall, 65 per cent of women will become pregnant within 18 months after an ectopic.

Who is at risk of an ectopic pregnancy?

Any sexually active woman of childbearing age has a risk of an ectopic pregnancy. However, ectopic pregnancies are more likely if you have had:

- Pelvic inflammatory disease

- Endometriosis

- Any previous abdominal surgery

- A coil fitted

- Are on the progesterone-only contraceptive pill (mini pill)

The Ectopic Pregnancy Trust helpline is on 01895 238025; website: www.ectopic.org