Anna Watkins will not compete at Rio 2016 with Katherine Grainger

Great Britain's Anna Watkins has told Katherine Grainger she will not defend their double sculls Olympic title at Rio 2016 after the birth of her son.

However, 30-year-old Watkins could return for the Tokyo Olympics in 2020.

Grainger, 38, whose gold at London 2012 came after she was a silver medallist at the previous three Games, is yet to announce her plans.

"Rowing has to take a back seat for a while while other life-changing events take precedence," Watkins said.

"Post London I knew I'd have an enormous quandary on my hands, especially after having my son William. As an athlete, I have put so much into rowing, it took everything I had to get to that level."

It is unclear whether Watkins, who won bronze in the double sculls at the Beijing Olympics in 2008, will compete in a different event in Rio.

However, she is contemplating competing in Tokyo in six years, with an option being the single sculls, in which Great Britain have never won a medal.

She added: "I definitely have the drive to want to do it all again. Rio is pretty unlikely - I'm kind of busy. But a Tokyo 2020 comeback is a really exciting idea."

In three seasons together, between 2010 and 2012, Watkins, who is based in Berkshire, and Grainger won all of their 23 races.