Double Olympic gold medallist Shelly-Ann Fraser-Pryce of Jamaica will not defend her 100 metres title at this year's World Athletics Championships in London ©Getty Images

Double Olympic gold medallist Shelly-Ann Fraser-Pryce of Jamaica will not defend her 100 metres title at this year's World Athletics Championships in London after announcing she is pregnant.

The 30-year-old, who won bronze at the 2016 Olympic Games in Rio de Janeiro, is hoping to return to the track in 2018.

The Jamaican, winner of the 100m Olympic gold medal at Beijing 2008 and London 2012, had hoped to compete at the World Championships, scheduled for August 5 to 13.

She has vowed to be the "greatest mother she can be" in announcing the news on Facebook.

"All my focus heading into training for my 2017 season was on getting healthy and putting myself in the best possible fitness to successfully defend my title in London 2017," Fraser-Pryce wrote.

Shelly-Ann Fraser-Pryce won relay silver and individual 100m bronze at Rio 2016 ©Getty Images
Shelly-Ann Fraser-Pryce won relay silver and individual 100m bronze at Rio 2016 ©Getty Images

"But life is filled with many blessings with God, so here I am thinking about being the greatest mother I can be with my biggest blessing and the promise God made me."

Fraser-Pryce has seven World Championships gold medals to her name and would have again been a threat in London, despite enduring a difficult 2016, where she was hampered for large periods by injury.

The Jamaican was also a part of the women's 4x100m relay team which took silver at Rio 2016.

"Moving forward on this journey, I look forward to seeing you all in 2018 when I return to competition on the tracks and around the world," she added.

"Thank you to my sponsors Nike, GraceKennedy and Digicel for their unwavering support and a loyal fan base that's willing to join and share in my journey."