The 32-year-old, who claimed her Olympic medal in the 4x400m relay in 2016, is due to give birth six months before the 2020 Toyko games.

First Minister Nicola Sturgeon was one of the first to offer congratulations to the Scottish runner and hurdler.

"I'm not retiring yet, I'm planning to get back," said the three-time Commonwealth Games silver medallist.

Doyle, the Scottish record holder at 400m hurdles and the indoor 400m, has also won medals at world and European level.