The pregnancy was announced in November and the baby was due to be born in spring 2017.
Queen Elizabeth's granddaughter Zara and her husband Mike Tindall have lost the baby they had been anticipating, days before Christmas.
Equestrian champion Zara, the Queen's granddaughter, and former England rugby star Mr Tindall announced last month they were expecting their second child. They were reportedly "trilled" at the prospect of Mia having a baby brother or sister. The child would have been the Queen and Prince Phillip's sixth great-grandchild.
Zara Phillips and Mike Tindall suffer a miscarriage in Christmas tragedy
The spokeswoman wouldn't not give any further details about the circumstances surrounding the miscarriage, but Zara is not believed to be in medical danger.
The couple's daughter Mia is almost two. "At this hard time, we ask that everyone respects their privacy", she said. A Buckingham Palace rep confirmed the heartbreaking news to Us Weekly on Saturday, just a day before Christmas.
Sophie underwent a two-and-a-half-hour operation during which surgeons removed the foetus from her Fallopian tube. They had baby Mia three years later. She switched to her married name this year.
San Diego Chargers at Cleveland Browns
RGIII was taken off the field and evaluated for a concussion with 12 minutes remaining in the game. Griffin's exit came in the midst of the Browns and Chargers exchanging seven consecutive punts.