The journalist initially announced that she would take a hiatus from the ABC morning show on Friday, August 31 to undergo a bone marrow transplant.
Roberts told Good Morning America viewers today (August 30) that she had moved her hiatus up a day to visit her mother in Mississippi, which has been hard-hit by Hurricane Isaac.
"Dear ones, this is my final morn @GMA for a while. Heading home after the show to be w/ my ailing mum in MS. You'll be in my heart & soul," she tweeted earlier.
She will soon have surgery with marrow donated by her sister Sally-Ann in order to help her recover from myelodysplastic syndrome (MDS).
Roberts has said she is very optimistic about her eventual return to Good Morning America. The presenter has anchored the programme for the last seven years.
She also famously battled breast cancer in 2007.