When Aileen Smith meets people in the North Yorkshire town where she has lived and worked for 60 years, few call her by her name.

Maureen Worley and Kathleen Reynard have become accustomed to the same socially awkward situation when shopping in Thirsk – despite being well-known figures in the community.

This apparent paradox, however, has a simple, if extremely unusual, explanation – Maureen, Aileen and Kathleen are identical triplets and their friends fear getting their names wrong.

The O’Brien triplets, who this month celebrated their 60th birthdays with a fundraising party at Thirsk Town Hall, said their features and mannerisms are still so similar their families – even their grandchildren – continue to get them muddled up.

While in the past this confusion proved a source of frustration for the sisters, Maureen says she has gradually come to accept the situation and treats it as a bit of a running joke.

She said: “It is quite hard at times and can be frustrating, but over the last 10 years we have laughed more about it.”

Kathleen, who helps run Thirsk In Bloom, adds: “People very rarely call us by our names. Sometimes they will look at me and say ‘Which one are you?’ Others say ‘Hello’ and then get embarrassed, because they are Maureen or Aileen’s friends.

“Other times people say ‘I saw you the other day and you didn’t speak’. So I tell people I will smile if I see them on the street.”

The Multiple Births Foundation estimates that, while triplets occur once in every 10,000 naturally conceived births, the chance of identical triplets being born are at least one in 150,000.

The odds of identical triplets born in the post-war period all living to the age of 60 are much longer.

Advances in obstetric practice and perinatal care have greatly increased the survival rates of premature triplets, so when Hilda O’Brien gave birth to Maureen, Aileen and Kathleen two months before her due date, on April 30, 1952, doctors were amazed they all survived.

First born at the Mount Hospital, Northallerton, weighing 4lbs 2ozs, was Maureen, and then in less than 30 minutes followed Aileen, at 4lbs 7ozs, and Kathleen, who weighed 3lbs 4ozs.

Their arrival stunned Mrs O’Brien, who was 33 and already had two children, Joanna, five, and John, three, as she had been expecting just one child.

Such was the rarity of triplets being born, the Queen sent the family a letter of congratulations and £1 for each girl.

The sisters speak with immense pride about how their mother, who died last New Year’s Eve, aged 92, coped with five children under the age of six, despite their father’s regular absences and little money.

Kathleen said while friends and family rallied to help, their mother’s time was so stretched she could be found washing clothes at 1am.

She said: “Nowadays, families who have identical triplets usually get sponsorship, but mum had nothing and after we were born we had to move house because there wasn’t enough room.

“Also, it wasn’t easy to find the equipment needed for the three of us then. They had to go to Leeds for a quad pram.

“After I had my first child, I got a bit low, but when I thought about my mother’s situation, it immediately pulled me together.”

From the outset, Mrs O’Brien dressed the girls in identical outfits – which homeopath Aileen says was the accepted thing to do with multiple birth children in the 1950s – and at junior school they had to wear name badges.

As youngsters, they never had individual photographs taken and it wasn’t until they started at Thirsk School aged 11 that they were allowed to dress differently.

The sisters say being treated in this way had some profound effects on their early lives.

Maureen, who works in the school’s food and textiles department and runs the town’s Royal British Legion band, said: “We never had a best friend because they always felt they had to be friendly with all three of us.

“People still assume that if one of us likes red we all like red, if one of us votes Labour we all do, like we don’t have independent minds.”

Nevertheless, the triplets, who each had three children, passed their driving tests in the same week and married joiners, talk animatedly about their shared passions for music and the guides movement.

The sisters are also keen to highlight several telepathic experiences associated with identical siblings, which they are at a loss to explain.

When they were about 14, they went out separately to buy presents for three friends, and all returned with the same perfume packs.

Aileen said: “When Maureen was pregnant with her first daughter, I went on holiday and as I was coming back I got stomach cramps and backache. Then at 3pm they suddenly went. It was only when I spoke to my mum that I found out Maureen had had her baby, with it arriving at 3pm.”