The public defender for Jeffery Reynolds changed his client's plea from a plea of not guilty during a hearing, The (Baton Rouge) Advocate reported Monday.
Reynolds, 31, told reporters "I love my wife" as he walked to the courtroom. He did not say anything in court.
Reynolds is charged with first-degree homicide, attempted second-degree homicide and battery on a police officer.
Police allege he stabbed his pregnant wife, Paula, in October, cut the fetus from her, called 911 and fought officers when they arrived.
Paula Reynolds survived.
His attorney, Jasper S. Brock, asked District Judge Beth Wolf to set a date for a sanity hearing.