A British woman has given birth to a set of healthy identical triplets – an event that happens only in about one in 150,000 pregnancies.

Mae Christina Astley, 25, had the three girls, called Amy, Kim and Zoe, delivered by Caesarean section at Feldkirch State Hospital in Western Austria on Monday.

The three babies, who were conceived naturally without IVF treatment, were delivered prematurely at 32 weeks, each weighing 3.3lb (1.5kg). All are doing well, although they are weak and are being cared for in the hospital’s intensive care unit.

The children’s Austrian father, Thomas Graziadei, 27, told the local newspaper Vorarlberger Nachrichten: “We thank God that everything went well. But they all look the same. I don’t know how we are going to tell them apart when they have not got their hospital wristbands on.”

Miss Astley told the newspaper: “I was conscious but had an epidural so was able to witness it all.”

Her doctor, Peter Schwarzler, said that although the babies were born prematurely and identical triplet pregnancies are among the most dangerous, he expected them to survive and develop normally.

“We need to be careful over the next few days but we are confident that all will go well,” he said. “They are currently getting breathing support, as is usual. The triplets were born in the 32nd week and, as is normal with such premature births, the lungs are not so resilient and fatigue sets in easily.”

Identical triplets are created either when a single fertilised egg divides into three, or when one embryo splits into two to form identical twin embryos, and then one of these divides again. They account for about 6 per cent of all triplet pregnancies.

Identical triplets occur in between one in 130,000 and one in 150,000 pregnancies, although many of these are not carried to term because of complications. About ten sets of identical triplets are conceived in Britain each year.

All triplet pregnancies have a higher risk of miscarriage; stillbirth; death in the first weeks of life; birth defects; and serious disabilities, and these are elevated when the triplets are identical and share a placenta.

Nicholas Fisk, Professor of Obstetrics and Foetal Medicine at Imperial College, London, said that his own centre had experienced 17 identical twin pregnancies in the past 13 years and he had delivered two sets of identical quadruplets. “Identical triplets are not as rare as you might think,” he said. “We generally see a case referred to us about once a year. The outcomes, unfortunately, are often not good. You have all the risks of triplet pregnancies, along with all the risks of sharing a placenta. Around 40 to 50 per cent of these pregnancies end with an adverse outcome.”

While many women who conceive nonidentical triplets opt for foetal reduction – a selective abortion that improves the chances of a healthy outcome for the remaining foetuses – this is also more difficult for identical triplets.

“There is no easy way to do a reduction when there is only one placenta,” Professor Fisk said. “Continuing these pregnancies is often difficult and dangerous.”

Multiple choices

— Multiple births make up one in 68 births compared with one in 98 a decade ago and the pace is accelerating. If the trend were to continue, twins would outnumber singletons by the year 2179

— IVF mostly accounts for the increase in nonidentical twins. The trend for identical multiple births is generally static, despite the large increase in the number of women giving birth later in life. The chances of having identicals increases with age

— Identical twins Reggie and Ronnie Kray scandalised the nation in the 1960s. Ross and Norris McWhirter amazed children across the country in the 1970s. The Olsen twins have made a fortune in the fashion world and the Cheeky Girls capitalised on their image to break into the music business

— Oliver James, the child psychologist, believes that the greatest risk for identicals growing up is the “script” given to them by their parents. Desperate to differentiate between their children, parents often label one as “outgoing” and the other “shy”, or one “clever” and the other “artistic”

— Identicals appear to be a random event and are distributed uniformly in all countries

— Studies on identical twins separated and reared in different environments show that they share similar personality traits, mannerisms, job choices, attitudes and interests

Source: Times database

Times Recommends

• Sarah Brown says 'no thanks' to veal at G8 - twice
• Stockton-on-Tees is obesity capital of Britain
• Stores blame poor sales on Murray factor