A British couple has beaten odds of a million to one by having two sets of identical twin girls, The Sun reported Monday.
Newborns Isabella and Chloe Dawson had to fight a life-or-death battle to join their six-year-old sisters Lilly and Sophie.
They were delivered two months prematurely with breathing problems and had to spend weeks in intensive care.
Parents Michele and James Dawson already endured a worrying time when the babies needed an operation to survive while still in the womb.
At 20 weeks old the girls developed deadly twin-to-twin transfusion syndrome, where one takes vital nutrients from the other.
A team at London's King's College Hospital saved their lives by performing keyhole laser surgery to separate the placenta. The babies remained in the womb for three more months.
At 32 weeks, they were delivered by C-section at London's St. Mary's Hospital on May 19. Both weighed three pounds, three ounces.
They are now well and being cared for by their proud twin sisters back home in Northaw, southern England.
"When I learned I was expecting my first set of twins it took three days for the news to sink in so imagine how I felt this time," Michele Dawson, 34, said.
"To hit the twin jackpot was lucky but to do it again six years later is incredible. They're all gorgeous, our pride and joy. We are blessed, though we may need to extend the house soon," she added.
Lilly and Sophie were born on April 22, 2005, weighing four pounds, eight ounces and three pounds, six ounces.
All the girls were born without the aid of fertility drugs or IVF, known to boost the likelihood of multiple births.