ST. PAUL (AP) - A St. Paul woman has pleaded guilty to first-degree manslaughter for suffocating her infant son.

The Ramsey County Attorney's office says 23-year-old Shwe Htoo entered her plea Thursday in the November 2015 death of her 5-week-old son, Michael Kyaw Htoo.

Htoo initially was ruled incompetent to stand trial but later was found competent. A charge of second-degree murder will be dismissed when she's sentenced next month.

As part of the plea agreement, Htoo admitted her fed her son formula tainted with poison. When she found him still alive the next morning, she suffocated him using a blanket and her hands.

Htoo then loaded her son into the back seat of a car and drove it into a light pole in Como Park.

She faces up to 15 years in prison.