ST. PAUL (AP) - A St. Paul mother has been sentenced to 15 years in prison for fatally smothering her newborn son.

Twenty-three-year-old Shwe Htoo pleaded guilty to first-degree manslaughter in the November 2015 death of the 5-week-old Michael Htoo.

Prosecutors acknowledged the mother struggled with postpartum depression, but said Htoo knew what she was doing with she filled her son's bottle with poison and fed it to him. When that failed to kill him, Htoo smothered her child with her hands.

A charge of second-degree murder was dismissed as part of an agreement with prosecutors.

Htoo cried during the sentencing hearing Wednesday in Ramsey County court, but declined to speak despite her defense attorney's advice to offer a statement.