By Dana Ford

LOS ANGELES (Reuters Life!) - Celebrity socialite and mother-to-be Nicole Richie has opted to serve her jail time for driving under the influence of drugs at the same detention center that TV sidekick Paris Hilton called home for about three weeks.

"Her attorney has contacted us and indicated that Ms. Richie wants to do her sentence in the L.A. County jail," Steve Whitmore, spokesman for the Los Angeles County Sheriff's Department, said on Friday.

Richie, 25, pleaded guilty last week to a misdemeanor DUI charge and was sentenced to four days in jail, with the option of serving her time in a sprawling county lockup for women or in a "pay-to-stay" program operated by a nearby municipality, like Burbank.

Although county jails are considered tougher than city jails, county inmates are often eligible for early release on good behavior because of overcrowding at those facilities. Whitmore declined to comment on whether Richie would be eligible for such a release, but presumably she will be.

Hilton, who co-stars with Richie on "The Simple Life," was sentenced earlier this year to 45 days in county jail for violating her probation in a drunken driving case. She ended up serving 22 days, most of that at the Century Regional Detention Facility for women in suburban Lynwood.

Richie's guilty plea stems from a traffic stop in December in which police said she was driving the wrong way on a Los Angeles-area freeway. Police said Richie failed a field sobriety test and told officers she had smoked marijuana and taken the painkiller Vicodin.

Interest in Richie's case intensified over the last few months because of speculation that the skinny star is pregnant with her first child.

Richie and her boyfriend Joel Madden, lead singer of the rock band Good Charlotte, confirmed she was expecting a baby in an interview that aired on Thursday with ABC's Diane Sawyer.

In the interview, a contrite Richie said she recognized the seriousness of her mistakes and looked forward to a healthier and more responsible future.

In his first comments since she was sentenced, Richie's father, pop singer Lionel Richie, told Us Weekly magazine that he tried to teach his daughter the importance of accepting the consequences of her actions.

"She has not blamed others for her problems and is growing up very quickly, albeit in the heat of the media spotlight," he said. "Her pregnancy has given her a new perspective on life in general."

Nicole Richie has until Sept. 28 to begin serving her sentence. It was not immediately known when she would surrender to authorities.