Meet Julia Padgett, her identical twin sister, Ruth, and Julia’s identical twin sons, Joseph and Thomas.

It was a one-in-62,500 chance, and it happened.

Being an identical twin is rare enough – one in 250 pregnancies. But the chance of an identical twin giving birth to identical twins is almost unheard of.

Non-identical twins often run in families, occurring when two eggs are fertilized in women who are predisposed to release more than one at the same time.

But there is nothing genetic about identical twins, so the chance of it happening twice in one family is extremely rare.

“It’s completely random and not hereditary. It happens between day two and day four of your pregnancy, when the fertilised egg splits in two,” said Julia, 33. Julia told her mum, Anne, about the twins after she had her first scan.

“I sat down and showed her one picture and said ‘this is your next grandchild’, then showed her another and said ‘and this is your next grandchild’. She was quite shocked.”

Joseph and Thomas were born in August after a difficult pregnancy. “Having twins puts more pressure on your body,” said Julia. “The first 28 weeks were a breeze, but after that I had complications.”

Julia developed cholecystitis, a rare condition that affects the liver and can be dangerous for the mother and the unborn babies. She was monitored closely and went into labour six weeks early.

She and her husband, Richard, 43, went to York Hospital, but there were not enough special care cots, so they transferred to Scarborough District General Hospital and the boys were delivered by caesarean section.

After two weeks, Julia and Richard were able to take their babies back home to Wigginton.

Julia, a research manager, said it was useful having a mum who had had twins herself for advice.

“But she does say the first year was a blur. She also had to look after our older brother, Hugh, who was two when we were born.”

Julia can also look to twin sister Ruth, who has sons Finley, four, and Isaac, three, for support.

“Having a twin sister is great, particularly with her having two boys herself,” said Julia. Richard, a sales manager, is very proud of his boys, who are now five months old and have just started to recognise and smile at each other.

Rachel Gardiner-Hill, of the Twins And Multiple Birth Association, said: “Identical twins are completely random and for this to happen is extremely rare. I have been working with the association for ten years and have heard of only two or three cases like this.”