July 18 will always be an expensive day for the Hefer family.
Four years ago on that day, Kim Hefer gave birth to twin boys. Incredibly, on the same day, she gave birth to another set after four years.
It is believed to be the first time a pair of naturally conceived twin boys have been born on the same day in different years in Britain.
Although the chances of a mother who has had one set of non-identical twins having another are quite high, it is almost unheard of to have another set on the same day. Mathematicians say the odds are 500,000-1.
Her husband Freddie, 30, a financial manager for Deutsche Bank, said they had been expecting the babies on August 13, but they arrived four weeks early after Mrs Hefer was taken to hospital with high blood pressure.
Logan was born at 11.50pm weighing 5lb 5oz, and Devon a minute later at 6lb 3oz.
‘Tristan and Blake are very excited about their new brothers and said they can’t wait to play with them.’
But she added: ‘We’re definitely not planning to have any more children – I think two sets of twins is quite enough.’ There are only six families in the world with two sets of twins born on the same date.