Pregnant star Nicole Richie has checked into an 18-month anti-drinking program in California, according to reports.

The 26-year-old Simple Life star signed up for the SB 38 Alcohol Program on Sept. 26, according to documents obtained by People.com.

The course is for people convicted of driving under the influence more than once within seven years--according to the Santa Barbara Council on Alcoholism and Drug Abuse.

Richie was arrested for DUI on Dec. 11 after she was spotted driving the wrong way down Highway 134 in southern California. She admitted to smoking marijuana and taking the painkiller Vicodin.

In the course, Richie will have to undergo 52 hours of group counseling, biweekly face-to-face interviews and 12 hours of alcohol education.