(Reuters) - Vivian Cheruiyot is not defending her world 5,000 and 10,000 meters gold medals in Moscow in August because she is expecting her first child, the Kenyan said in a statement.
The 29-year-old, who won both races at the 2011 world athletics championships in Daegu, South Korea, took silver and bronze in the 5,000 and 10,000 at last year's London Olympics.
In a statement released by her agent Ricky Simms on Wednesday, Cheruiyot said she would resume her career next year. She had first revealed her decision not to compete in Moscow on Tuesday but gave no reason for her absence.
"I am very happy to announce that I will take some time off from athletics this year as I am pregnant with my first child," she said. "I have been running for many years and at 29 feel that now is the right time to start a family.
"I have already spoken to some of my colleagues who had babies to get advice about when to return to training after giving birth," she said, adding that her long term goal was "to finally win Olympic gold."
The world championships will be held in the Russian capital from August 10-18.
(Writing by Peter Rutherford in Singapore; Editing by Patrick Johnston)