A British servicewoman has given birth in Afghanistan, after not realising she was pregnant.

The woman, who is originally from Fiji, had a healthy son at Camp Bastion on Tuesday.

Both mother and baby are in a stable condition and will be flown home in the coming days.

A specialist medical team from the John Radcliffe Hospital in Oxford is due to arrive in the Helmand Province base to help take them home.

The birth took place just four days after the camp, where the bulk of the UK's 9,500-strong force is deployed, was attacked by Taliban insurgents who destroyed six aircraft and killed two US Marines.

An MoD spokesman said: "We can confirm that on September 18 a UK servicewoman serving in Afghanistan gave birth in the Camp Bastion Field Hospital to a baby boy.

"Mother and baby are both in a stable condition in the hospital and are receiving the best possible care.

"A specialist paediatric retrieval team is being prepared and will deploy in the next few days in order to provide appropriate care for mother and baby on the flight home."

The spokesman added: "It is not military policy to allow servicewomen to deploy on operations if they are pregnant. In this instance the MoD was unaware of her pregnancy.

"As with all medical cases, when the need arises, individuals are returned to the UK for appropriate treatment/care."

According to the Daily Mail, the woman served as a gunner with the Royal Artillery, and had been deployed with the 17th Mechanised Brigade since March.

The newspaper said she only discovered she was pregnant after she went to medics complaining of stomach pains, and the baby was born five weeks prematurely.

A military expert called for more rigorous checks on women going to frontline duties to ensure they are not pregnant because of the risks to their welfare.

Major Charles Heyman, an author of books about the British Army and a former soldier, said he understood a simple urine test could have disclosed the woman's condition.

"The Army needs to make sure, for the welfare of the female soldier concerned, that they are not pregnant before they deploy.

"I'm not an expert on pregnancy but I'm told that it is easy to tell that a woman is pregnant with a visit to a doctors' surgery and a urine test and that should perhaps be looked at before women go out on operations.

"This whole situation does surprise me. Whatever rules you put down, there is also someone who slips by to have a baby in an operational theatre, but it's quite unusual.

"This sort of thing makes life difficult for everyone else but the important thing is the welfare of the female soldier. This could have gone wrong and we don't know if the attack on Camp Bastion might have forced the birth.

"It's maybe that the excitement of the tour masked the symptoms of the pregnancy, but I know it's not a good thing for a woman or the baby to be born there. It's not like they have a maternity wing out there.

"Perhaps because of that the baby should be called Bastion."

Maj Heyman said the training and checks undergone by the woman would not have picked up a problem as it was too early.

"All soldiers going out to theatre go through training and checks. But as far as I can make out she was out there for four or five months before she gave birth and was pregnant when she deployed.

"A lot of the training for her was six months before she went out.

"She was also based at Camp Bastion which, relative to the rest of Afghanistan, is a peaceable place despite the recent attack and not a hell-hole like Nad-e Ali.

"Also the physical requirements for logistics personnel are different from frontline infantry, who are basically athletes.

"Logistics personnel need to be fit but the situation is different for them."

Belinda Phipps, chief executive of the National Childbirth Trust, said it was unusual for a woman not to know she was pregnant until the last minute.

But she said that being in such a stressful situation as an operational tour in Afghanistan could take a woman's focus away from her body.

"Most of us put on two or three stone (28-42lbs) while we are pregnant and by the end of pregnancy feel very much as though it is dominating our entire being, so it would be hard to get to the later stages of pregnancy and not realise it," she said.

"However, the symptoms of pregnancy vary in their intensity from one woman to another and bump size can also differ a lot.

"If you are young or in your 40s when the pattern of your periods may vary and you may be experiencing other physical changes, it is easier not to realise you are pregnant.

"Also if you don't expect to be pregnant, are busy and stressful or in a life or death situation, you may be so focused on what is happening in your life that you don't spot or put to the back of your mind the signs of pregnancy you may be experiencing."

The woman who gave birth is not the first to have been pregnant while on the frontline.

Last year it emerged that Private Kayla Donnelly, then 21, from Penrith, Cumbria, gave birth just two weeks after leaving Afghanistan.

She did not know she was carrying her baby while fighting in Helmand province from March to September 2010.

The machine gunner from 12 Logistic Support only discovered she was pregnant with her son Josh when her contractions began while on holiday in Tenerife.

Around 500 of the 9,500 British forces in Afghanistan are women.