NAIROBI, May 22 (Xinhua) -- Kenya's Vivian Cheruiyot will not be able to defend her 5,000 meters and 10,000 meters titles at this year's Moscow world championships as she is expecting her first child.

The runner said in a statement on Wednesday that she felt it was "the right time to start a family" at the age of 29.

Cheruiyot planned to return for the 2014 season and compete in the 2015 World championships in Beijing.

Cheruiyot has not competed since she won a 5,000m silver and 10,000m bronze medal at the London Olympics last August.