The murder conviction of an Alberta woman who admitted to killing her newborn son has now been overturned.

Katrina Effert was found guilty of second-degree murder and received a life sentence with no parole for at least ten years. She admitted to strangling her newborn son hours after giving birth in her parent's home.

In a nine-page document, Alberta's Court of Appeal has found the jury could not have fully understood the evidence of two mental health experts.

Both experts said when a then 19-year-old Effert gave birth in her parents' home in 2005, and subsequently strangled her newborn, "her mind was disturbed."

Now, the murder conviction has been set aside and in its place, she will be sentenced for infanticide.

Alberta Justice stands by the case prosecutors made in court and believes the jury made the right decision.

"We believe the evidence supports a conviction for second-degree murder and that's what we argued in court. Obviously the Court of Appeal didn't agree with us. We'll be making a thorough review of the decision before we take any next steps," said spokesperson Carla Kolke.

The maximum sentence for an infanticide conviction is just five years.

No date has been set yet for sentencing.

With files from David Ewasuk