A Wiltshire woman has made medical history after falling pregnant while already pregnant.
Rebecca Roberts, 39, is now the mother of twins Noah and Rosalie - who were born at the same time but conceived a month apart.
The medical phenomenon, known as superfetation, is incredibly rare and occurs when a second egg is fertilised weeks after a first one. Experts believe there may only be 10 cases of it worldwide.
Miss Roberts, who lives in Trowbridge, found out about the 'double pregnancy' when she went for her 12-week scan for baby Noah.
"To find out I was having twins - I was really shocked, obviously because they originally said there was only one baby," she said.
"But to find out we were having these special twins was remarkable. I Googled it to try and learn a bit about it but there's nothing out there."
Noah and Rosalie are considered twins, despite being conceived on different occasions. They were delivered early by caesarean at Bath's Royal United Hospital due to a problem with Rosalie's umbilical cord.
Noah weighed 4lb 10oz, while his 'younger' sister was just 2lb 3oz. Rosalie had to stay in hospital longer than her twin, but both are now back at home in Trowbridge. They even have their own Instagram page.