Stephanie Greene
Stephanie Greene

A mother who killed her daughter with poisoned breast milk has been jailed for 20 years.

Nurse Stephanie Greene, 39, from South Carolina obtained morphine and other painkillers without telling doctors that she was pregnant.

Her six-week-year-old daughter, Alexis, died in 2010, and a toxicology report found lethal amounts of four drugs in her system. The amount would have been enough to kill an adult, the court heard.

Greene was found guilty of homicide by child abuse, involuntary manslaughter and unlawful neglect of a child.

"This is not an indictment on breast feeding," said solicitor Barry Barnette.

"She loved her drugs more than she loved her baby."

Greene's defence team argued that not enough of the drugs could have been passed through the breast milk to have killed the child, but the prosecution argued that there was no evidence that the child had been killed in another way.

Greene was convicted of homicide by child abuse, involuntary manslaughter and unlawful conduct towards a child.

Under South Carolina law, she must serve at least 16 years in jail.