OTTAWA -- The Supreme Court of Canada says an Alberta woman who tossed two of her newborn children into the garbage is not guilty of second-degree murder.

By a 7-0 margin, the high court has agreed with the lawyers for Meredith Borowiec of Calgary, who argued that she was guilty of the lesser offence of infanticide.

The Supreme Court was ruling for the first time on the infanticide provision of the Criminal Code, which turns on the definition of what constitutes a disturbed mind for a new mother.

Borowiec was originally charged with two counts of second-degree murder for the deaths of two of her children in 2008 and 2009.

In 2014, she was convicted of infanticide and sentenced to an additional 18 months in jail on top of the 18 months she had already spent in custody. Alberta's Court of Appeal upheld the infanticide verdicts, but it was a split decision, meaning the matter automatically moved to the Supreme Court.