James, Joshua, Lauren and Emily are the children of Sharon and Julian Turner, who had been trying to conceive since 2009 using in vitro fertilization,
The Daily Telegraph reported Thursday.
"It's been quite a journey. We found out it was to be a multiple birth at the 12-week scan. We were absolutely overjoyed. At each scan it seemed the doctors were surprised that everything was still going well," Julian Turner said.
It was difficult to tell the twins apart, he said.
"I've been told the odds of having two sets of identical twins are something like 70,000,000 to one," Turner said. "The hospital hasn't seen quads for fifteen years, although one or two sets are born in the U.K. each year. And they've never had two sets of identical twins, ever."
The date of the quadruplets' birth after 29 weeks, three days gestation at John Radcliffe Hospital in Oxford was not reported. Doctors said that after being placed in intensive-care incubators, the babies were healthy enough to be transferred to the Royal Berkshire Hospital in Reading, closer the Turners' home.