ST. CHARLES COUNTY — Prescription drug problems led a Lincoln County woman back to prison Monday, more than three years after drinking during pregnancy killed her baby.

Sherri J. Lohnstein, 36, of Foley, had been on probation for involuntary manslaughter for the death of her daughter, Zreanna. Circuit Judge Nancy Schneider revoked Lohnstein's probation Monday, ordering her to serve a seven-year sentence.

"Apparently, Ms. Lohnstein has not been clean and sober since being placed on probation," Schneider said.

Lohnstein was drunk on Sept. 9, 2006, when doctors at a Lake Saint Louis hospital performed an emergency Caesarean section. Her blood-alcohol level was 0.18 percent. Zreanna, who died of acute intoxication, had a blood-alcohol level of 0.17 percent.

In Missouri, a driver is presumed to be intoxicated at 0.08 percent.

Lohnstein pleaded guilty in December 2007 in exchange for a recommendation that she complete a prison treatment program and be placed on probation for five years. After her release from the treatment program, she also was to complete drug court, a program that combines drug testing, treatment and consequences for offenders with addiction problems.

She completed the prison treatment program, but Karla Duryea, a state Division of Probation and Parole worker, said Lohnstein was kicked out of Lincoln Court drug court.

Duryea said Lohnstein went to an emergency room to get prescriptions for painkillers and tried using old prescriptions to get the drugs. She said Lohnstein was warned several times, but she never stayed off drugs.

Richard Scheibe, who heads the public defender's office in St. Charles County, said Lohnstein had several health problems. He said she received the drugs from doctors who were qualified to decide whether she needed them.

There was no evidence that Lohnstein used alcohol, Scheibe said, and while the court programs she was assigned to might not have fit her problems, she did not violate probation. He asked Schneider to keep Lohnstein on probation.

Assistant prosecutor Carrie Barth said Lohnstein had been given several opportunities to receive help, and the court had no choice now but to send her to prison.

Lohnstein said little during Monday's hearing. She wiped tears from her eyes as she said goodbye to her boyfriend, Jim Harrison, who was Zreanna's father. Harrison and Lohnstein have been raising Lohnstein's older daughter. While in prison, Lohnstein gave birth to another daughter, whom she put up for adoption.

St. Charles County Prosecutor Jack Banas said Lohnstein will receive credit for time she spent in jail and in the prison treatment program.