Preliminary information from officials at Centinela Freeman Regional Medical Center, where Donda West died Saturday at 58, indicated she died from "complications of surgery," Lt. Fred Corral told The Associated Press. An autopsy was to be conducted by Wednesday, Corral said.
Patricia Green, a consultant who has worked as a publicist for West in the past, had previously told news agencies that West died after cosmetic surgery. She backed away from those comments in later interviews with the AP, saying she was not sure of the cause because she had received conflicting information.
Donda West, the former chairwoman of Chicago State University's English department, died Saturday night in Los Angeles, said a spokesman for West, who asked for anonymity because not all family members had been notified.
"The family respectfully asks for privacy during this time of grief," the spokesman said.
Donda West was known for the strong bond she shared with her son, by whose side she was often seen at parties and award shows.
Kanye West, 30, often spoke of his close relationship with his mother, who raised him alone after her husband left when Kanye was 3.
She was the inspiration for the song, "Hey Mama," on Kanye West's 2005 album "Late Registration," in which he sings: "Hey Mama, I wanna scream so loud for you, cuz I'm so proud of you ... I appreciate what you allowed for me. I just want you to be proud of me."
Donda West frequently defended her son against critics who accused him of penning misogynistic lyrics and other purported transgressions.
"I support my baby," she said in a Chicago Sun-Times interview. "He is telling how he feels and he is speaking the truth as he sees it."
In May, she published the book "Raising Kanye: Life Lessons from the Mother of a Hip-Hop Star," in which she paid homage to her famous son.
Donda West served as chief executive of West Brands LLC, the parent company of her son's business enterprises, and as chairwoman of the Kanye West Foundation, an educational nonprofit that works to decrease dropout rates and improve literacy.
Kanye West told the Associated Press in August that he and his mother worked together to devise the foundation's first program, "Loop Dreams," which helps public school students get involved in music.
"Me and my mother were discussing ways to give back and came up with the concept," he said.
Donda West worked in higher education for 31 years, before leaving academia in 2004 to help manage her son's career, according to a biography on the Kanye West Foundation's Web site.
She began working at Chicago State University in 1980 and eventually chaired the school's English department, according to the site. She started her teaching career in the early 1970s as an instructor at Brown College in Atlanta.
Kanye West's writing partner Rhymefest lamented Donda West's death Sunday in an appearance on Chicago radio station WCGI.
"She was everyone's mom," Rhymefest said. "A spirit never dies, a spirit lasts forever.