Olympic champion Adlington says she suffered miscarriage

Double Olympic gold medallist Rebecca Adlington suffered a miscarriage at 12 weeks into her pregnancy and underwent emergency surgery, the now-retired British swimmer said on social media.

Adlington, who won the 400 and 800 metres freestyle titles at the 2008 Beijing Olympics, shared the news in an Instagram post on Saturday with a photo of her lying in a hospital bed with a cup of tea and an IV line in the back of her hand.

"On Tuesday me and Andy (her husband) went to hospital for our 12 week scan only to discover we've had a miscarriage which resulted in emergency surgery," Adlington said.

"I managed to leave hospital Thursday only to be readmitted Friday. After a day of treating sepsis, a kidney infection and a fever I'm slowly on the mend. Long way to go but I'm in the right place.

"It's such a devastating time but important in times like these we remember we aren't alone and have so much support."

Adlington has two children - a seven-year-old daughter from her previous marriage to fellow swimmer Harry Needs and a one-year-old son with husband Andy Parsons.