The British endurance track cyclist, who has previously suffered with endometriosis, confirmed that she was expecting her first child.
Barker rode in the qualifying round of the team pursuit as Great Britain secured silver behind a world record setting German quartet in the final.
Five times a world champion, Barker was part of the British unit that won gold in Rio de Janeiro in 2016, alongside Laura Kenny (then Trott), Katie Archibald and Joanna Rowsell.
Barker’s younger sister Megan is riding at the European Championships in Grenchen, Switzerland this week ahead of the Track Cycling World Championships in Roubaix, France, which begin in two weeks.
Road cycling team Uno-X have announced that the elder Barker will join them and return to the road for the next two seasons after her pregnancy.
The new women’s team have also secured the signing of former British national champion Hannah Barnes from Canyon-SRAM for their inaugural 2022 season.