"(Richie's) attorney contacted us and indicated she wants to do her time" at Century Regional Detention Facility in Lynwood, Calif., said Steve Whitmore, spokesman for the Los Angeles County Sheriff's Department.
Whitmore couldn't say whether Richie, who's four months pregnant, would be housed at the facility's medical ward, People reported Thursday.
"That's all determined by our medical staff upon her arrival," Whitmore said.
Richie's sentence arises from her arrest for driving under the influence Dec. 11 to which she pleaded guilty last week. Besides the four days in jail, Richie was sentenced to three years of probation, an alcohol education program and fined $2,048.
Hilton served 23 days in jail in June for violating terms of her probation.